This work was supported by the UOIT start-up fund. We thank Mr. Matthew Baxter (UOIT) for his assistance in the laboratory.

1. Sintesi di Ynone <ol><li> Utilizzando una bilancia analitica, pesare 0,15 mmol di potassio desiderato sale alkynyltrifluoroborate (1,5 equivalenti) e aggiungere ad una fiala pulita dotata di ancoretta magnetica. </li><li> Usando una siringa di vetro stantuffo con ago, aggiungere 0,5 ml di DCM anidro alla fiala di permettersi una soluzione 0.3 M di trifluoroborate. NOTA: Dal momento che si tratta di una nuova metodologia, le reazioni sono state eseguite per prova di concetto. Al fine di ridurre i rifiuti che sono stati effettuati su piccola scala. La reazione può essere scalata a produrre rendimenti più grandi come richiesto. </li><li> Usando una siringa di vetro, aggiungere 0,15 mmoli di 1,0 M soluzione di tricloruro di boro (1,5 equivalenti, 150 microlitri) goccia a goccia nel recipiente di reazione a temperatura ambiente (20 ° C) sotto agitazione. Sostituire il tappo. Tenere o bloccare il recipiente di reazione capped tale che la soluzione di reazione è al di sotto della linea di galleggiamento in sonicatore. Sonicare la soluzione per 30 sec a 20 ° C e una frequenza of 40 kHz. </li><li> Mescolare la soluzione di reazione a temperatura ambiente (20 ° C) per un ulteriore 20 min. A seconda della natura del materiale di partenza alkynyltrifluoroborate, osservare un cambiamento di colore. Un cambiamento di colore dal bianco al marrone chiaro o marrone scuro, rosso, o viola è comune. </li><li> Aggiungere 0,1 mmoli di cloruro acilico desiderato (1,0 equivalenti) al flaconcino a temperatura ambiente (20 ° C) sotto agitazione. In alternativa, trasferire il contenuto del recipiente di reazione in un pallone caricato con ancoretta magnetica e 0,1 mmoli di cloruro acilico. Sostituire il tappo. Mescolare la soluzione di reazione a temperatura ambiente (20 ° C) per 30 min. NOTA: Generalmente, una modifica a un colore molto scuro è un&#39;indicazione che la reazione ha luogo. </li><li> Utilizzando una cromatografia su strato sottile (TLC) 34 monitorare l&#39;andamento della reazione confrontando con appropriata norma cloruro acilico. NOTA: A seconda della natura dei materiali di partenza, la reazione non può andare a completamento. L&#39;acyl cloruro di materiale di partenza è stato osservato come un punto di funzionamento più elevata del prodotto finale per tutte le ynones preparati per data utilizzando questo metodo. <ol><li> Preparare lo standard cloruro acilico diluendo circa 10 mg di cloruro acilico materiale di partenza di 1 ml di acetato di etile in una piccola fiala. </li><li> Utilizzando un spotter TLC, individuare la soluzione di reazione e lo standard sulla linea di partenza della piastra TLC. Un co-spot con la soluzione di reazione e standard può essere utile per determinare se vi è ancora materiale di partenza presenti nella soluzione di reazione. </li><li> Determinare un adeguato fase mobile TLC per tentativi ed errori. Per la preparazione del prodotto 1a, una fase mobile consistente 1:30 acetato di etile: esani produce valori R f di circa 0,5 e 0,8 per il prodotto ynone e cloruro di benzoile materiale di partenza, rispettivamente. </li><li> Visualizza la piastra TLC sviluppata sotto la luce UV. Utilizzare una matita per segnare tutti i punti visibili. </li></ol></li></ol> 2. acquosa Workup <ol><li> Quench la reazione aggiungendo 1 ml di acqua fredda (circa 5 ° C) al recipiente di reazione. Usando una pipetta Pasteur, trasferire la soluzione in un imbuto separatore pulita. Diluire ulteriormente il contenuto del imbuto separatore con 10 ml di acqua fredda ed estrarre il prodotto una volta in 15 ml di acetato di etile. </li><li> Eliminare lo strato acquoso inferiore e lavare lo strato una volta in più organica con 10 ml di acqua e una volta con 10 ml di salamoia. Raccogliere la fase organica in una beuta pulita e asciutta con solfato di magnesio. Filtrare la soluzione in un pallone a fondo tondo pulito con filtrazione a gravità. </li></ol> 3. Purificazione di Ynone <ol><li> Usando cromatografia su strato sottile, determinare una fase mobile adatto per la purificazione cromatografia flash del prodotto. Un fattore di ritenzione (R f) di circa 0,5 è generalmente sufficiente per separare il prodotto da qualsiasi dall&#39;inizio rimanenteing materiali e prodotti collaterali. NOTA: Nel caso di separazione poveri, un sistema solvente meno polare può essere utilizzato in modo tale che il prodotto ha un valore f R inferiore. A seconda della polarità dei materiali di partenza, una miscela esano: acetato di etile nell&#39;intervallo di 30: 1 a 5: 1 è generalmente adatto. </li><li> Preparare una colonna contenente silice bagnata con la fase mobile appropriata. Aggiungere uno strato di sabbia alla parte superiore della colonna in modo da non disturbare silice dopo l&#39;aggiunta del prodotto e eluente. </li><li> Evaporare la soluzione workup utilizzando un evaporatore rotante con la temperatura del bagno a 40 ° C e la rotazione impostato a 120 rpm. Sciogliere il contenuto del pallone in un 2 ml di fase mobile e caricare la soluzione con attenzione in modo uniforme sulla colonna. Assicurarsi che la silice è bagnato ma la linea del solvente non superi l&#39;altezza della silice. Ad alcuni solvente per eluire tale che il prodotto è silice. Aggiungere una piccola quantità di fase mobile e ripetere. </li><li> Riempire il colleumn con la fase mobile determinata al punto 3.1; nel caso del prodotto 1a, a 30: 1 esani: miscela acetato di etile è appropriato. Raccogliere le frazioni in provette mediante cromatografia flash per accelerare il processo di purificazione. È sufficiente collegare un adattatore con tubi a una presa d&#39;aria. Regolare la pressione dell&#39;aria in modo tale che l&#39;eluente scorre attraverso la colonna ad una velocità adeguata. </li><li> Spot ciascuna delle frazioni di colonna su una piastra TLC. Facoltativamente, individuare lo standard cloruro acilico come riferimento. Sviluppare il TLC con la fase mobile ritenuto opportuno nella fase 1.8. Segnare eventuali macchie visibili ai raggi UV, notando che il prodotto dovrebbe avere un R f inferiore allo standard acilcloruro. </li><li> Raccogliere tutte le frazioni contenenti macchie visibili in un grande pallone a fondo tondo. Se più di un punto con un R f inferiore al materiale di partenza è presente, raccoglierle in flaconi separati. Si evapora il solvente usando un evaporatore rotante e asciugare il materiale raccolto under alto vuoto per due ore. </li><li> Se necessario, effettuare un lavaggio pentano su una piccola colonna per purificare ulteriormente un prodotto ynone preparato da una scarsa cloruro acilico materiale di partenza di elettroni. Su una scala ridotta, ciò può essere eseguita usando una pipetta Pasteur come colonna. <ol><li> Sciogliere il prodotto in un minimo di cloroformio, DCM, o dietiletere e il carico su una colonna di silice bagnata con pentano. Eluire 1-2 lunghezze di colonna di pentano attraverso la colonna e raccogliere in un becher rifiuti. </li><li> Eluire il prodotto puro ynone dalla colonna pentano utilizzando dietiletere o acetato di etile. Raccogliere eluente in un pallone separato, evaporare, e posto sotto alto vuoto per almeno due ore. Ottenere circa 10 mg di prodotto per la caratterizzazione mediante spettroscopia NMR. </li></ol></li></ol> 4. Caratterizzazione di Ynone <ol><li> Caratterizzare e valutare la purezza del prodotto finale con 1 H e 13 spettroscopia NMR C. 34Tipicamente, il chemical shift del carbonio carbonilico appare vicino 177 ppm nello spettro 13 C NMR. I due carboni SP del gruppo funzionale ynone sono rappresentati dai picchi caratteristici vicino 87 e 93 ppm. </li><li> Utilizzare spettroscopia infrarossa 34 per identificare il picco caratteristico carbonilico del prodotto ynone. Electron delocalizzazione del triplo legame adiacente solito provoca il picco carbonilico appaia tra 1.600 e 1.650 cm-1, a seconda delle caratteristiche elettroniche del composto. </li><li> Determinare la massa molecolare del prodotto e convalidare ulteriormente l&#39;identità utilizzando la spettrometria di massa ad alta risoluzione. 34 </li></ol>

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W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+student's+lab+companion:+laboratory+techniques+for+organic+chemistry:+standard+scale+and+microscale.">The student's lab companion: laboratory techniques for organic chemistry: standard scale and microscale.</a> Pearson College Div. , (2008).</li><li>Molander, G. A., Cavalcanti, L. N., Canturk, B., Pan, P. -. S., Kennedy, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+Hydrolysis+of+Organotrifluoroborates+via+Silica+Gel+and+Water.">Efficient Hydrolysis of Organotrifluoroborates via Silica Gel and Water.</a> 74, 7364-7369 (2009).</li><li>Molander, G. A., Ellis, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organotrifluoroborates:+protected+boronic+acids+that+expand+the+versatility+of+the+Suzuki+coupling+reaction.">Organotrifluoroborates: protected boronic acids that expand the versatility of the Suzuki coupling reaction.</a> Acc. Chem. Res. 40, 275-286 (2007).</li><li>Calloway, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Friedel-Crafts+Syntheses.">The Friedel-Crafts Syntheses.</a> Chem. Rev. 17, 327-392 (1935).</li><li>Gore, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Friedel-Crafts+acylation+reaction+and+its+application+to+polycyclic+aromatic+hydrocarbons.">The Friedel-Crafts acylation reaction and its application to polycyclic aromatic hydrocarbons.</a> Chem. Rev. 55, 229-281 (1955).</li><li>Groves, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Friedel&#8211;Crafts+acylation+of+alkenes.">The Friedel&#8211;Crafts acylation of alkenes.</a> Chem. Soc. Rev. 1, 73-97 (1972).</li><li>Kim, B. J., Matteson, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conversion+of+alkyltrifluoroborates+into+alkyldichloroboranes+with+tetrachlorosilane+in+coordinating+solvents.">Conversion of alkyltrifluoroborates into alkyldichloroboranes with tetrachlorosilane in coordinating solvents.</a> Angew. Chem. 116, 3118-3120 (2004).</li><li>Thompson, L., Doraiswamy, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sonochemistry:+science+and+engineering.">Sonochemistry: science and engineering.</a> Ind. Eng. Chem. Res. 38, 1215-1249 (1999).</li></ol>

The authors declare that they have no competing financial interests.

La tabella 1 illustra le misure adottate per ottimizzare le condizioni per la reazione di fenilacetilene trifluoroborate con cloruro di benzoile per formare il prodotto ynone corrispondente. Inizialmente, catalizzatori noti per convertire organotrifluoroborates a organodifluoroboranes sono stati testati. Purtroppo gel di silice, tetracloruro di silicio 35, 36 e trifluoruro di boro 31,32 non promuove la formazione del ynone desiderato (Tabella 1, voci 1-3). L&#39;uso di clorurati catalizzatori acidi Lewis ha dimostrato di essere più successo. Una bassa resa del ynone 1a desiderato è stato ottenuto in presenza di un ferro (III) cloruro di catalizzatore (Tabella 1, voce 4). Successivamente, alluminio (III) cloruro è stato studiato come risultato della sua capacità consolidata per promuovere la formazione di ioni oxocarbenium in acylations Friedel-Crafts. 37-39 Il prodotto desiderato è stato ottenuto nel 62% di resa ottenuta con un alluminio (III) cloruro catalizzatore era employed. Ulteriore ottimizzazione rivelato che l&#39;aria e l&#39;umidità hanno scarso effetto sulla resa della reazione (Tabella 1, voci 5-7). Di conseguenza, le reazioni successive sono state effettuate in vetro non essiccato in presenza di aria. I tentativi di ottimizzare il solvente rivelato che diclorometano (DCM) è particolarmente adatto per la reazione (Tabella 1, voci 8-12). Le incoerenze nei risultati delle reazioni catalizzate da alluminio (III) cloruro richiesto l&#39;esplorazione di catalizzatori alternativi. Commercialmente alluminio disponibili (III) cloruro esaidrato era completamente inattivo nelle condizioni di reazione (Tabella 1, voce 13). Questo è un buon indicatore che la formazione di alluminio (III) cloruro idrato inibisce la reazione. Boro tricloruro stato trovato per produrre rese simili con maggiore coerenza (Tabella 1, voce 14). Su interazione del alkynyltriflu potassiooroborate con tricloruro di boro, a più reattivi specie organodichloroborane è formata. 40 Questa fase iniziale è fondamentale per la reazione con il cloruro acilico e formazione del ynone procedere. Poiché i sali organotrifluoroborate non sono solubili in DCM, la reazione avviene come miscela eterogenea. Dopo aggiunta di boro tricloruro, la soluzione è per facilitare la formazione delle specie reattive dichloroborane aumentando l&#39;area superficiale del sale trifluoroborate disponibili per reagire sonicato. Applicazione di ultrasuoni alla miscela di reazione provoca effetti meccanici attraverso la generazione di bolle di cavitazione. Durante sonicazione, collasso della cavitazione bolle nei risultati fluido in aree localizzate di alte temperature e pressioni. 41 onde d&#39;urto sono prodotti che creano turbolenze microscopica risultante in un aumento dell&#39;energia cinetica dei sali trifluoroborate solidi. L&#39;aumento di energia del sistema durante sonicazione promoTES frammentazione del sale trifluoroborate conseguente aumento della superficie disponibile per interagire con tricloruro di boro. Sonicazione della miscela di reazione prima dell&#39;aggiunta del materiale di partenza cloruro acilico assicura la formazione efficace delle specie reattive alkynyldichloroborane senza la necessità di ulteriori condizioni di separazione o tempi di reazione più lunghi. La Figura 2 illustra i risultati ottenuti quando fenilacetilene trifluoroborate stato fatto reagire con una varietà di cloruri acilici nelle condizioni di reazione ottimizzate. Neutral aromatico (1b, 1c) e alifatici (1 undecies-l) cloruri acilici fornire i ynones corrispondenti rendimenti sinteticamente utili. Quei cloruri acilici portanti gruppi elettron donatori (1d-g) offrono eccellenti rendimenti mentre i gruppi elettron producono rendimenti relativamente modesti (1h, 1i, 1m). Interestingly, quando il gruppo ritirare elettroni si trova in posizione orto (1i, 59%), un significativo aumento di resa è osservata rispetto al para analoghi sostituiti cloruro acilico (1h, 30%). L&#39;interazione sterico del sostituente in posizione orto- può forzare il gruppo funzionale carbonilico fuori dal piano, compensando così il carattere elettron-attrattore dell&#39;anello aromatico. Vale la pena notare che il cloruro di 4-bromobutirril reagito permettere il 1m prodotto desiderato nel 39% di rendimento. A nostra conoscenza, questo è il primo protocollo per la sintesi di ynones tollerare un gruppo funzionale alchilico bromuro. Occasionalmente, quando il cloruro acilico materiale di partenza è neutro o deficiente di elettroni, impurità alifatici appaiono sul NMR protonica. Ciò può richiedere un lavaggio pentano per purificare ulteriormente il prodotto. Mentre possibile, non è economico per effettuare il lavaggio pentano durante la prima fase di purificazione since pentano è costoso in confronto a esani. Completano la purificazione secondaria separatamente su scala minore, come una colonna pipetta Pasteur riduce significativamente la quantità di pentano necessaria. La figura 3 illustra l&#39;effetto dell&#39;identità del sale alkynyltrifluoroborate sulla resa della reazione. In generale, i derivati ​​di cuscinetti sale sostituenti elettron-donatori il fenilacetilene trifluoroborate sull&#39;anello aromatico reagito con cloruri acilici aromatici e alifatici per produrre i ynones desiderati in buono a rendimenti eccellenti (2a-c, 3a-c). Sali alkynyltrifluoroborate alifatici dimostrato di essere substrati meno reattivi. I rendimenti modesti sono stati ottenuti quando hexynyl- e sali cyclopentylethynyltrifluoroborate stati reagire con derivati ​​ricchi di elettroni di cloruro di benzoile (4a, 5a). In conclusione, un nuovo metodo per la preparazione of è stato sviluppato ynones da cloruri acilici e potassio sali alkynyltrifluoroborate. Le rese ottenute per la sintesi di ynones da questo intervallo metodo dal modesto eccellente a seconda della natura del cloruro acilico e trifluoroborate materiali di partenza. In generale, tali materiali di partenza recanti sostituenti elettron donatori subiscono la reazione più facilmente di materiali di partenza recanti gruppi funzionali neutri e elettron. Il valore di questo approccio risiede nella semplicità e gruppo funzionale tolleranza operativa del metodo. Questo semplice, reazione one-pot procede rapidamente a temperatura ambiente in presenza di boro tricloruro senza esclusione di aria e umidità. Questo metodo conveniente può essere impiegato nella preparazione di ynones in modesto ottime rese da una varietà di cloruri acilici e sali alkynyltrifluoroborate.

The intention of this video is to demonstrate a straightforward approach for the preparation of compounds containing an ynone functional group from convenient starting materials. Ynones are valuable building blocks in organic chemistry that have been shown to have biomedical and material significance. Ynones are precursors to valuable organic functional groups including pyrimidines,1,2 quinolones,3 furans,4 pyrazoles,5,6 flavones,7 oximes,8 and chiral propargylic alcohols.9-11 A more convenient method for the preparation of ynones has been sought as a result of the drawbacks of traditional methods including poor functional group tolerance and tedious synthetic routes.
The reaction of metal12,13 and metalloid14 acetylides with acyl chlorides is one common route for the preparation of ynones. Alternatively, the synthesis of ynones from acyl chloride can be achieved via two-step procedures using Weinreb amides and organolithium or Grignard reagents.15 Another prevalent approach includes the addition of organolithium or Grignard reagents to an aldehyde, which is followed by the oxidation of a secondary alcohol to the corresponding ketone.16-19 Poor functional group tolerance of metal acetylides and the need to purify synthetic intermediates after each step are main deficiencies of the aforementioned methods. Transition-metal-catalyzed carbonylative couplings have recently emerged as an alternative approach for the preparation of ynones.20-22 Unfortunately, in addition to cost and toxicity associated with transition metals, metal-catalyzed carbonylative reactions often require elevated CO pressures and suffer from the presence of an undesired Sonogashira coupling byproduct. Given their utility in organic synthesis as well as the drawbacks associated with traditional synthetic methods, the development of a more straightforward method for the preparation of ynones is appealing.
Potassium organotrifluoroborate salts have recently emerged as versatile reagents in organic synthesis. Advantages including ease of preparation,23 inherent stability, low toxicity, and good functional group tolerance have made organotrifluoroborate salts attractive synthetic reagents.24-27 Organotrifluoroborate salts have been used primarily as a bench-stable equivalent of boronic acids for palladium-catalyzed Suzuki-Miyaura coupling.26 Recently, following a seminal work by Matteson and co-workers,28 Bode, Molander and others have highlighted the utility of organotrifluoroborates as reagents in non-metal catalyzed reactions.29-33 The field of transition-metal-free reactions of trifluoroborates is still in its infancy stage. Given the great potential for use of organotrifluoroborate salts in non-metal catalyzed organic synthesis, we sought to develop a novel method for the preparation of ynones from acyl chlorides and alkynyltrifluoroborate salts.

<table border="0" cellpadding="0" cellspacing="0" width="573">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:71px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sonicator</td>
			<td style="width:71px;">VGT</td>
			<td style="width:119px;">1860QT</td>
			<td>Ultrasonic cleaner. Similar sonication devices may be used.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Dichloromethane</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:119px;">270997</td>
			<td>Anhydrous</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Boron trichloride solution&#160;</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:119px;">178934</td>
			<td>1M solution in DCM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Acyl chloride</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:119px;">Various</td>
			<td>Acyl chlorides from other suppliers such as Alfa Aesar may be used. Caution - refer to MSDS for safety information.</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Potassium alkynyltrifluoroborate salt</td>
			<td style="width:71px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td>Synthesized23 from terminal alkyne</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ethyl acetate</td>
			<td style="width:71px;">ACP</td>
			<td style="width:119px;">E-2000</td>
			<td>ACS grade</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Hexanes</td>
			<td style="width:71px;">ACP</td>
			<td style="width:119px;">H-3500</td>
			<td>ACS grade</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Pentane</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:119px;">236705</td>
			<td>Anhydrous</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Magnesium sulfate</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:119px;">M7506</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Filter paper</td>
			<td style="width:71px;">Whatman</td>
			<td style="width:119px;">1093 126</td>
			<td>Student grade. This speceific variety is not necessary.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Silica Gel 60</td>
			<td style="width:71px;">EMD</td>
			<td style="width:119px;">1.11567.9026</td>
			<td>Particle size 0.040-0.063</td>
		</tr>
	</tbody>
</table>

metal-free synthesis of ynones from acyl chlorides and potassium alkynyltrifluoroborate salts

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups and scaffolds. Traditional methods for the preparation of ynones are associated with drawbacks including harsh conditions, multiple purification steps, and the presence of unwanted byproducts. An alternative method for the straightforward preparation of ynones from acyl chlorides and potassium alkynyltrifluoroborate salts is described herein. The adoption of organotrifluoroborate salts as an alternative to organometallic reagents for the formation of new carbon-carbon bonds has a number of advantages. Potassium organotrifluoroborate salts are shelf stable, have good functional group tolerance, low toxicity, and a wide variety are straightforward to prepare. The title reaction proceeds rapidly at ambient temperature in the presence of a Lewis acid without the exclusion of air and moisture. Fair to excellent yields may be obtained via reaction of various aryl and alkyl acid chlorides with alkynyltrifluoroborate salts in the presence of boron trichloride.

Gli sforzi iniziali sono concentrati intorno alla preparazione di ynone 1a dal fenilacetilene trifluoroborate S1 e cloruro di benzoile (Figura 1). Tabella 1 illustra i passi di ottimizzazione eseguita compresa proiezione di vari acidi di Lewis, solventi, nonché esame l&#39;effetto dell&#39;acqua sulla reazione . Successivamente, la portata della reazione è stato esplorato presentando fenilacetilene trifluoroborate alle condizioni ottimizzate in presenza di una varietà di cloruri acilici (Figura 2). Modesto rese eccellenti possono essere ottenuti a seconda della natura del substrato cloruro acilico. La portata della reazione è stata ulteriormente valutata attraverso la preparazione di numerosi altri esempi di sali alkynyltrifluoroborate. La figura 3 illustra esempi selezionati di altri sali alkynyltrifluoroborate che possono essere impiegati nella preparazione dei ynones alle condizioni sviluppati. Derivati ​​di phenylacetylene elettrone cuscinetto trifluoroborate donazione sostituenti offerte i prodotti ynone corrispondenti in buona eccellenti rendimenti, mentre i derivati ​​alifatici di sali alkynyltrifluoroborate dimostrato di essere un po &#39;meno reattivi che offrano rendimenti modesti. <img alt="Figura 1" src="/files/ftp_upload/52401/52401fig1highres.jpg" /> Figura 1: Preparazione di Ynone 1a dal fenilacetilene trifluoroborate S1 e benzoil cloruro Scheme illustrando le condizioni per la preparazione di ynone 1a compresa formazione del dichloroborane intermedio reattivo.. <img alt="Figura 2" src="/files/ftp_upload/52401/52401fig2highres.jpg" /> Figura 2:. Rappresentante 1 H NMR del ynone 1a turni chimici e integrazioni relative di protoni caratteristici sono etichettati. Figura 3:. Rappresentante 13 C spettro NMR di ynone 1a cambiamenti chimici di carboni caratteristici sono etichettati. <img alt="Figura 4" src="/files/ftp_upload/52401/52401fig4highres.jpg" /> Figura 4:. Rappresentante spettro HRMS di ynone 1a ottenuta tramite ionizzazione chimica a pressione atmosferica Il valore m / z misurata del [M + H] + ioni viene segnalato. <img alt="Figura 5" src="/files/ftp_upload/52401/52401fig5highres.jpg" /> Figura 5: Reazioni di sale phenylacetylenetrifluoroborate S1 con cloruri acilici Strutture e dei rendimenti per i prodotti fabbricati variando l&#39;identità.del materiale di partenza cloruro acilico sono illustrati. Le reazioni sono state eseguite con 1 equiv di cloruro acilico, 1.5 equiv phenylacetylenetrifluoroborate potassio S1, e 1,5 equiv tricloruro di boro. <img alt="Figura 6" src="/files/ftp_upload/52401/52401fig6highres.jpg" /> Figura 6:. Reazioni di varie alkynyltrifluoroborates con cloruri acilici Strutture e rese dei prodotti ottenuti variando l&#39;identità del materiale di partenza alkynyltrifluoroborate sono illustrati. Le reazioni sono state eseguite con 1 equiv di cloruro acilico, 2,5 di potassio equiv sale organotrifluoroborate e 2,5 equiv tricloruro di boro. <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td> Ingresso </td><td> Acido di Lewis </td><td> Acido di Lewis (equiv) </td><td> Condizioni </td><td> Dare La Precedenza (%) </td></tr><tr><td> 1 b &lt;/ Sup&gt; </td><td> SiO 2 </td><td> 16.5 </td><td> CH 2 Cl 2 </td><td> 0 </td></tr><tr><td> 2 </td><td> SiCl 4 </td><td> 1 </td><td> CH 2 Cl 2 </td><td> traccia </td></tr><tr><td> 3 </td><td> BF 3 · OEt 2 </td><td> 1 </td><td> CH 2 Cl 2 </td><td> traccia </td></tr><tr><td> 4 b </td><td> FeCl 3 </td><td> 1 </td><td> CH 2 Cl 2 </td><td> 24 </td></tr><tr><td> 5 c </td><td> AlCl 3 </td><td> 1 </td><td> CH 2 Cl 2 </td><td> 62 </td></tr><tr><td> 6 d </td><td> AlCl 3 </td><td> 1 </td><td> CH 2 Cl 2 </td><td> 66 </td></tr><tr><td> 7 e </td><td> AlCl 3 </td><td> 1 </td><td> CH 2 Cl 2 </td><td> 60 </td></tr><tr><td> 8 </td><td> AlCl 3 </sub&gt; </td><td> 1 </td><td> THF </td><td> traccia </td></tr><tr><td> 9 </td><td> AlCl 3 </td><td> 1 </td><td> toluene </td><td> traccia </td></tr><tr><td> 10 </td><td> AlCl 3 </td><td> 2 </td><td> ClCH 2 CH 2 Cl </td><td> 33 </td></tr><tr><td> 11 </td><td> AlCl 3 </td><td> 1 </td><td> DMSO </td><td> traccia </td></tr><tr><td> 12 </td><td> AlCl 3 </td><td> 2 </td><td> acetonitrile </td><td> traccia </td></tr><tr><td> 13 </td><td> AlCl 3 · 6H 2 O </td><td> 1 </td><td> CH 2 Cl 2 </td><td> 0 </td></tr><tr><td> 14 b </td><td> BCL 3 </td><td> 1.5 </td><td> CH 2 Cl 2 </td><td> 67 </td></tr><tr><td> 15 </td><td> BBr 3 </td><td> 1 </td><td> CH 2 Cl 2 </td><td> 20 </td></tr></tbody></table><strong&gt; Tabella 1:. Ottimizzazione delle condizioni per la preparazione di ynone 1a un rendimento del prodotto 1a al variare delle condizioni di reazione e di catalizzatore acido di Lewis. A reazioni sono stati eseguiti con 1 equiv cloruro di benzoile e 1 equiv phenylacetylenetrifluoroborate potassio S1. B 1.5 equiv S1. C condizioni anidro. D La reazione è stata fatta in vetreria non essiccato sotto aria. E condizioni anidre + 1 ml di acqua.

Watch this Scientific Journal Video about Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts at JoVE.com

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts

The goal of this manuscript is to demonstrate a straightforward method for the preparation of ynones from acyl chloride and potassium alkynyltrifluoroborate salt starting materials. The one-pot reaction proceeds rapidly in the presence of boron trichloride without exclusion of air and moisture.

Sintesi senza metallo di Ynones da Acyl Cloruri e Potassio Alkynyltrifluoroborate Sali

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups ...

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11.1K Views.  University of Ontario Institute of Technology. The goal of this manuscript is to demonstrate a straightforward method for the preparation of ynones from acyl chloride and potassium alkynyltrifluoroborate salt starting materials. The one-pot reaction proceeds rapidly in the presence of boron trichloride without exclusion of air and moisture.

Video: Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts

Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of molecular iodine to samarium metal in THF.1,2-3 It is a mild and selective single electron reductant and its versatility is a result of its ability to initiate a wide range of reductions including C-C bond-forming and cascade or sequential reactions. SmI2 can reduce a variety of functional groups including sulfoxides and sulfones, phosphine oxides, epoxides, alkyl and aryl halides, carbonyls, and conjugated double bonds.2-12 One of the fascinating features of SmI-2-mediated reactions is the ability to manipulate the outcome of reactions through the selective use of cosolvents or additives. In most instances, additives are essential in controlling the rate of reduction and the chemo- or stereoselectivity of reactions.13-14 Additives commonly utilized to fine tune the reactivity of SmI2 can be classified into three major groups: (1) Lewis bases (HMPA, other electron-donor ligands, chelating ethers, etc.), (2) proton sources (alcohols, water etc.), and (3) inorganic additives (Ni(acac)2, FeCl3, etc).3
Understanding the mechanism of SmI2 reactions and the role of the additives enables utilization of the full potential of the reagent in organic synthesis. The Sm-Barbier reaction is chosen to illustrate the synthetic importance and mechanistic role of two common additives: HMPA and Ni(II) in this reaction. The Sm-Barbier reaction is similar to the traditional Grignard reaction with the only difference being that the alkyl halide, carbonyl, and Sm reductant are mixed simultaneously in one pot.1,15 Examples of Sm-mediated Barbier reactions with a range of coupling partners have been reported,1,3,7,10,12 and have been utilized in key steps of the synthesis of large natural products.16,17 Previous studies on the effect of additives on SmI2 reactions have shown that HMPA enhances the reduction potential of SmI2 by coordinating to the samarium metal center, producing a more powerful,13-14,18 sterically encumbered reductant19-21 and in some cases playing an integral role in post electron-transfer steps facilitating subsequent bond-forming events.22 In the Sm-Barbier reaction, HMPA has been shown to additionally activate the alkyl halide by forming a complex in a pre-equilibrium step.23
Ni(II) salts are a catalytic additive used frequently in Sm-mediated transformations.24-27 Though critical for success, the mechanistic role of Ni(II) was not known in these reactions. Recently it has been shown that SmI2 reduces Ni(II) to Ni(0), and the reaction is then carried out through organometallic Ni(0) chemistry.28
These mechanistic studies highlight that although the same Barbier product is obtained, the use of different additives in the SmI2 reaction drastically alters the mechanistic pathway of the reaction. The protocol for running these SmI2-initiated reactions is described.

Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.

Preparazione ed uso di samario diioduro (SMI<sub&gt; 2</sub&gt;) Nella sintesi organica: il ruolo meccanicistico di HMPA e Ni (II) sali nella reazione Samario Barbier

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of ...

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Chimica

Nucleoside Triphosphates - From Synthesis to Biochemical Characterization

The traditional strategy for the introduction of chemical functionalities is the use of solid-phase synthesis by appending suitably modified phosphoramidite precursors to the nascent chain. However, the conditions used during the synthesis and the restriction to rather short sequences hamper the applicability of this methodology. On the other hand, modified nucleoside triphosphates are activated building blocks that have been employed for the mild introduction of numerous functional groups into nucleic acids, a strategy that paves the way for the use of modified nucleic acids in a wide-ranging palette of practical applications such as functional tagging and generation of ribozymes and DNAzymes. One of the major challenges resides in the intricacy of the methodology leading to the isolation and characterization of these nucleoside analogues.
	
	In this video article, we present a detailed protocol for the synthesis of these modified analogues using phosphorous(III)-based reagents. In addition, the procedure for their biochemical characterization is divulged, with a special emphasis on primer extension reactions and TdT tailing polymerization. This detailed protocol will be of use for the crafting of modified dNTPs and their further use in chemical biology.

The protocol described herein aims to explain and abridge the numerous obstacles in the way of the intricate route leading to modified nucleoside triphosphates. Consequently, this protocol facilitates both the synthesis of these activated building-blocks and their availability for practical applications.

Nucleosidi trifosfati - Dalla sintesi di biochimica Caratterizzazione

The  traditional strategy for the introduction of chemical functionalities is the  use of solid-phase synthesis by appending suitably modified ...

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

Sintesi e caratterizzazione di funzionalizzato metallo-organici quadri

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

Sintesi e caratterizzazione di supramolecolari colloidi

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

Hydroquinone Based Synthesis of Gold Nanorods

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the synthetic methods for the preparation of gold nanorods are still not fully optimized. In this paper we describe a new, highly efficient, two-step protocol based on the use of hydroquinone as a mild reducing agent. Our approach allows the preparation of nanorods with a good control of size and aspect ratio (AR) simply by varying the amount of hexadecyl trimethylammonium bromide (CTAB) and silver ions (Ag+) present in the "growth solution". By using this method, it is possible to markedly reduce the amount of CTAB, an expensive and cytotoxic reagent, necessary to obtain the elongated shape. Gold nanorods with an aspect ratio of about 3 can be obtained in the presence of just 50 mM of CTAB (versus 100 mM used in the standard protocol based on the use of ascorbic acid), while shorter gold nanorods are obtained using a concentration as low as 10 mM.

This paper describes a protocol for the synthesis of gold nanorods, based on the use of hydroquinone as reducing agent, plus the different mechanisms for controlling their size and aspect ratio.

Idrochinone Based Sintesi di oro Nanorods

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the ...

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. Detailed and generalized protocols are also presented for testing the catalytic activity of such complexes in arylation and Suzuki-Miyaura cross-coupling reactions. Representative results are shown for the catalytic activity of the four complexes in arylation and Suzuki-Miyaura type reactions. For each of the reactions investigated, at least one of the four complexes successfully catalyzed the reaction, qualifying them as promising candidates for catalysis of many carbon-carbon bond-forming reactions. The protocols presented are general enough to be adapted for the synthesis, purification and catalytic activity testing of new palladium N-heterocyclic carbene complexes.

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. The complexes were tested for catalytic activity in arylation and Suzuki-Miyaura reactions. For each reaction investigated, at least one of the four complexes successfully catalyzed the reaction.

Palladio<em&gt; N</em&gt; Complessi di Carbene eterocicliche: Sintesi dei sali di benzimidazolium e attività catalitica in reazioni di formazione di legame di carbonio-carbonio

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from ...

Synthesis and Mass Spectrometry Analysis of Oligo-peptoids

Peptoids are sequence-controlled peptide-mimicking oligomers consisting of N-alkylated glycine units. Among many potential applications, peptoids have been thought of as a type of molecular information storage. Mass spectrometry analysis has been considered the method of choice for sequencing peptoids. Peptoids can be synthesized via solid phase chemistry using a repeating two-step reaction cycle. Here we present a method to manually synthesize oligo-peptoids and to analyze the sequence of the peptoids using tandem mass spectrometry (MS/MS) techniques. The sample peptoid is a nonamer consisting of alternating N-(2-methyloxyethyl)glycine (Nme) and N-(2-phenylethyl)glycine (Npe), as well as an N-(2-aminoethyl)glycine (Nae) at the N-terminus. The sequence formula of the peptoid is Ac-Nae-(Npe-Nme)4-NH2, where Ac is the acetyl group. The synthesis takes place in a commercially available solid-phase reaction vessel. The rink amide resin is used as the solid support to yield the peptoid with an amide group at the C-terminus. The resulting peptoid product is subjected to sequence analysis using a triple-quadrupole mass spectrometer coupled to an electrospray ionization source. The MS/MS measurement produces a spectrum of fragment ions resulting from the dissociation of charged peptoid. The fragment ions are sorted out based on the values of their mass-to-charge ratio (m/z). The m/z values of the fragment ions are compared against the nominal masses of theoretically predicted fragment ions, according to the scheme of peptoid fragmentation. The analysis generates a fragmentation pattern of the charged peptoid. The fragmentation pattern is correlated to the monomer sequence of the neutral peptoid. In this regard, MS analysis reads out the sequence information of the peptoids.

A protocol is described for the manual synthesis of oligo-peptoids followed by sequence analysis by mass spectrometry.

Sintesi e analisi di spettrometria di massa di Oligo-peptoids

Peptoids are sequence-controlled peptide-mimicking oligomers consisting of N-alkylated glycine units. Among many potential applications, peptoids have ...

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine

Amino alcohols are versatile compounds with a wide range of applications. For instance, they have been used as chiral scaffolds in organic synthesis. Their synthesis by conventional organic chemistry often requires tedious multi-step synthesis processes, with difficult control of the stereochemical outcome. We present a protocol to enzymatically synthetize amino alcohols starting from the readily available L-lysine in 48 h. This protocol combines two chemical reactions that are very difficult to conduct by conventional organic synthesis. In the first step, the regio- and diastereoselective oxidation of an unactivated C-H bond of the lysine side-chain is catalyzed by a dioxygenase; a second regio- and diastereoselective oxidation catalyzed by a regiodivergent dioxygenase can lead to the formation of the 1,2-diols. In the last step, the carboxylic group of the alpha amino acid is cleaved by a pyridoxal-phosphate (PLP) decarboxylase (DC). This decarboxylative step only affects the alpha carbon of the amino acid, retaining the hydroxy-substituted stereogenic center in a beta/gamma position. The resulting amino alcohols are therefore optically enriched. The protocol was successfully applied to the semipreparative-scale synthesis of four amino alcohols. Monitoring of the reactions was conducted by high performance liquid chromatography (HPLC) after derivatization by 1-fluoro-2,4-dinitrobenzene. Straightforward purification by solid-phase extraction (SPE) afforded the amino alcohols with excellent yields (93% to &#62;95%).

Chiral amino alcohols are versatile molecules for use as scaffolds in organic synthesis. Starting from L-lysine, we synthesize amino alcohols by an enzymatic cascade reaction combining diastereoselective C-H oxidation catalyzed by dioxygenase followed by cleavage of the carboxylic acid moiety of the corresponding hydroxyl amino acid by a decarboxylase.

Reazioni a cascata enzimatica per la sintesi di Amino alcoli chirali da L-lisina

Amino alcohols are versatile compounds with a wide range of applications. For instance, they have been used as chiral scaffolds in organic synthesis. ...

Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a challenge, as it requires asymmetric growth of symmetric crystals. Here, we report a distinctive synthesis of substrate-bound Au nanowires. This template-free synthesis employs thiolated ligands and substrate adsorption to achieve the continuous asymmetric deposition of Au in solution at ambient conditions. The thiolated ligand prevented the Au deposition on the exposed surface of the seeds, so the Au deposition only occurs at the interface between the Au seeds and the substrate. The side of the newly deposited Au nanowires is immediately covered with the thiolated ligand, while the bottom facing the substrate remains ligand-free and active for the next round of Au deposition. We further demonstrate that this Au nanowire growth can be induced on various substrates, and different thiolated ligands can be used to regulate the surface chemistry of the nanowires. The diameter of the nanowires can also be controlled with mixed ligands, in which another &#34;bad&#34; ligand could turn on the lateral growth. With the understanding of the mechanism, Au nanowire-based nanostructures can be designed and synthesized.

We report a solution-based method to synthesize substrate-bound Au nanowires. By tuning the molecular ligands used during the synthesis, the Au nanowires can be grown from various substrates with different surface properties. Au nanowire-based nanostructures can also be synthesized by adjusting the reaction parameters.

Sintesi di nanofili Au associato a substrato tramite un meccanismo di crescita superficiale attiva

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a ...

Synthesis and Characterization of Amphiphilic Gold Nanoparticles

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of their interactions with cell membranes, lipid bilayers, and viruses. The hydrophilic ligands make these particles colloidally stable in aqueous solutions and the combination with hydrophobic ligands creates an amphiphilic particle that can be loaded with hydrophobic drugs, fuse with the lipid membranes, and resist nonspecific protein adsorption. Many of these properties depend on nanoparticle size and the composition of the ligand shell. It is, therefore, crucial to have a reproducible synthetic method and reliable characterization techniques that allow the determination of nanoparticle properties and the ligand shell composition. Here, a one-phase chemical reduction, followed by a thorough purification to synthesize these nanoparticles with diameters below 5 nm, is presented. The ratio between the two ligands on the surface of the nanoparticle can be tuned through their stoichiometric ratio used during synthesis. We demonstrate how various routine techniques, such as transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and ultraviolet-visible (UV-Vis) spectrometry, are combined to comprehensively characterize the physicochemical parameters of the nanoparticles.

Amphiphilic gold nanoparticles can be used in many biological applications. A protocol to synthesize gold nanoparticles coated by a binary mixture of ligands and a detailed characterization of these particles is presented.

Sintesi e caratterizzazione delle nanoparticelle d'oro dell'anfifile

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of ...