RAF bu çalışmaları desteklemek için Ulusal Bilim Vakfı (CHE-0844946) teşekkür eder.

1. SMI 2 sentezi (0.1 M) <ol><li> Alev bir 50 ml&#39;lik yuvarlak dipli balon kurumaya ve argon ile yıkayın. Bir karıştırma çubuğu ekleyin ve septa ile şişesi kapağı. Samaryum metali (0.2 g, 1.3 mmol) tartılır ve tekrar argon ile şişeyi çalkalama, şişeye ilave edin. </li><li> Iyot kristaller (0.254 g, 2.0 mmol), ardından 10 mL kuru, gazı iyice tetrahidrofuran (THF) ilave edilir. Burnun bir argon balon ekleyin; Bu reaksiyon üzerinde Ar atmosferde bir pozitif basınç tutar. </li><li> 3 saat boyunca oda sıcaklığında kuvvetli bir şekilde karıştırarak. SMI 2 üretilir gibi çözüm renk değişiklikleri çeşitli geçer; turuncu sarı (45 dk), ve sonunda mavi dönüşür yeşil (1 saat) izledi. </li><li> Nihai lacivert renk tek başına iyonlaşmış samaryum oluştuğuna göstergesidir. Tam dönüşüm sağlamak amacıyla, sentez SMI 2 kullanılmadan önce en az 3 saat süreyle çözelti karıştırılır. </li></ol> 2. Samarium Barbier Reaksiyon-heksametilfosforamid (HMPA) Toplama <ol><li> SMI 2-HMPA kompleks hale getirmek için, argon altında, taze hazırlanmış SMI 2 (10 ml, 0.1 M, 1.0 mmol) almak ve argon altında bir şırınga, damla damla yoluyla HMPA ve 1.75 ml (10 eşdeğer., 10 mmol) ilave edin. Derin mor renk formları. </li><li> Ayrı bir argon, eklenti iodododecane (0.45 mmol, 110 ul), 3-pentanon (0.45 mmol, 48 ul) ve kuru THF içinde 2 ml altında temiz, kuru bir şişe içinde. </li><li> SMI 2 / HMPA kompleksi damla damla substrat çözeltisi karışımı ekleyin. </li><li> Karıştırarak 5 dakika içinde, mor renk reaksiyon sonunda gösteren, bulanık bakmaya başlar. </li><li> Reaksiyon tamamlandıktan sonra, gidermek için havaya maruz çözelti, sarı renk değişimleri daha fazla karıştırma üzerine. </li><li> Reaksiyon daha sonra doymuş sulu amonyum klorür ile yıkama ile işlenmiş. Bir ayırma hunisine solüsyonu eklenir ve dietil eter (5 mi) ilave edilir. Dinç sallama kaldırdıktan sonraüst organik tabaka, daha fazla dietil eter ekleyin. Sulu tabaka iki kere daha ayıklamak ve daha sonra organik katmanlar, her bir araya getirir. </li><li> Sulu sodyum tiyosülfatın bir doymuş çözeltisi ile organik tabaka yıkayın. Su ve sonra tuzlu su ile yıkama ile son yıkamadan ve ardından alt tabaka sulu, kaldırın. En iyi organik tabaka elde edilir ve çözelti içinde su bulunan herhangi bir son miktarı kadar emmek için magnezyum sülfat ekleyin. </li><li> HMPA fazla çıkarmak için Florisil tıpası içinden çözelti geçirir. </li><li> Barbier ürünü elde etmek için bir döner buharlaştırıcı üzerinde konsantre çözelti. Ürün GCMS ve 1H NMR ile tespit edilmiştir. 23 </li></ol> 3. Samaryum Barbier Reaksiyon-Ni (acac) 2 Katalistli <ol><li> Ni (acac) 2 (1 mol%, 0.01 mmol, 0.0026 g) tartılır ve argon altında gazı alınmış THF içinde 3 ml ihtiva eden bir temiz, kuru bir şişeye eklenir. Taze hazırlanmış ler için bir şırınga aracılığıyla Ni (acac) 2 çözeltisi ekle0.1 M SMI 2 (1.0 mmol, 10 mL) olution. </li><li> Ayrı bir argon, eklenti iodododecane (0.45 mmol, 110 ul), 3-pentanon (0.45 mmol, 48 ul) ve kuru THF içinde 2 ml altında temiz, kuru bir şişe içinde. </li><li> SMI 2 / Ni karışımına damla damla substrat solüsyonu eklenir. </li><li> Karıştırarak on beş dakika içinde, mavi renk reaksiyon sonunda gösteren bir sarı-yeşil renk oluşturmak için dağılacaktır. </li><li> Reaksiyon tamamlandıktan sonra, gidermek için havaya maruz çözelti, sarı renk değişimleri daha fazla karıştırma üzerine. 0.1 M aq ile yıkayarak reaksiyonu çalışın. Hidroklorik asit (3 ml) eklenmiştir. Bir ayırma hunisine solüsyonu eklenir ve dietil eter (5 mi) ilave edilir. </li><li> Sodyum tiyosülfat, su ve tuzlu su, sulu bir çözelti ile birlikte daha önce tarif protokol, ve magnezyum sülfat üzerinde kurutulur kullanarak organik tabaka yıkayın. Barbier ürün elde etmek üzere konsantre çözelti. Ürün GCMS ve 1H NMR ile tespit edilebilir. 28 </skadar&gt; </li></ol>

<ol>
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Çıkar çatışması ilan etti.

En yaygın katkı maddeleri kullanılarak iki SMI 2 çözeltisi ve organik sentez uygulanışı üretmek için bir basit bir prosedür sunulmuştur. Iki örnek ince ayar SMI 2 reaktivitesi ile reaksiyon mekanik kavrama bölgesinin önemini tasvir tanımlanmıştır. Reaksiyon mekanizmasının temelinin bilinmesi onların reaksiyon ihtiyaçlarına göre sentetik kimyagerler tarafından adapte edilecek bu reaktifin kullanılmasına izin verir. Bu tek elektron homojen indirgeyici kullanımı kolaydır ve ticari kaynaklardan satın alınabilir. Yukarıdaki protokol eylemsiz şartlar altında yapıldığında yalındır iken, ortak sorun giderme yordamları bazıları şunlardır: (a) Sm metal havaya uzun süre maruz Etti (b) bir olabilir, THF düzgün gazı ve kuru olduğundan emin olun dış tabaka okside, temiz bir metal yüzeyini ortaya çıkaracak şekilde bir havan ve pestal ile metal öğütmek (c)Alev kuru argon altında, bütün cam eşya ve serin, (d) daha sonra metal ile etkileşim için gösterildiği gibi argon, azot fazla inert atmosfer tercih edilir (e) SM metal fazlalığının varlığı SMI konsantrasyonunu korumaya yardımcı olur iyot kristali 2, (f) resublime.

<table border="1"><tbody><tr><td> Reaktif Adı </td><td> Şirket </td><td> Katalog numarası </td><td> Yorumlar (isteğe bağlı) </td></tr><tr><td> Samaryum metal </td><td> Acros </td><td> 29478-0100 </td><td> -40 Mesh,% 99.9 (metaller bazında) </td></tr><tr><td> THF </td><td> OmniSolv </td><td> TX0282-1 </td><td> Yenilikçi Teknolojiler solvent arıtma sistemi ile saflaştırılmış. Alternatif olarak ücretsiz-pompa-çözülme yöntemi ile giderildi edilebilir </td></tr><tr><td> Iyot </td><td> Alfa Aesar </td><td> 41955-22 </td><td> Resublimed kristaller,% 99.8 </td></tr><tr><td> Iodododecane </td><td> Acros </td><td> 25009-0250 </td><td> % 98 </td></tr><tr><td> 3-pentanon </td><td> Alfa Aesar </td><td> AAA15297-AE </td><td> % 99 </td></tr><tr><td> HMPA </td><td> Alderich </td><td> H11602 </td><td> % 98; Argon altında CaO dan damıtmak </td></tr><tr><td> Nii 2 </td><td> Alfa Aesar </td><td> 22893 </td><td> % 99.5 (metaller bazında) </td></tr></tbody></table>

preparation and use of samarium diiodide (smi2) in organic synthesis: the mechanistic role of hmpa and ni(ii) salts in the samarium barbier reaction

Başlangıçta ezoterik bir reaktif kabul olsa da, SMI 2 sentetik organik kimyacılar için ortak bir araç haline gelmiştir. SMI 2 THF içinde samaryum metal moleküler iyot eklenmesiyle oluşturulur. 1,2-3 bir hafif ve seçici bir elektron redükleyici ve çok yönlülüğü CC azaltılması dahil olmak üzere, geniş bir yelpazede başlatmak kabiliyetini bir sonucudur-bağ şekillendirme ve kaskad veya ardışık reaksiyonlar. SMI 2 sülfoksitler ve sülfonlar, fosfin oksitler, epoksitler, alkil ve aril halojenürler, karbonil, ve konjüge çift bağ da dahil olmak üzere fonksiyonel grupların çeşitli azaltabilir. SMI-2-aracılı reaksiyon ilginç özelliklerinden biri, 2-12 yeteneği solvent veya katkı seçici kullanımı yoluyla reaksiyon sonucu işleyebilirsiniz. Çoğu durumlarda, katkı maddeleri redüksiyon oranı ile kemo-ya da stereoselektivite reaksiyonların kontrol edilmesinde çok önemlidir. 13-14 Katkı commonly SMI 2 reaktivitesi üç ana gruba ayrılabilir hassas bir şekilde ayarlamak için kullanılmaktadır: (1) Lewis bazları (HMPA, diğer elektron-verici ligandlar, çelatlama eterler gibi), (2) proton kaynağı (alkoller, su, vs ), ve (3) inorganik katkı maddeleri (Ni (acac) 2, FeCl 3, vs.) 3. SMI 2 reaksiyon mekanizması ve katkı maddelerinin rolünü anlamak organik sentez içinde reaktif bir tam potansiyel kullanımı sağlanmaktadır. Bu reaksiyon için HMPA ve Ni (II): Sm-Barbier reaksiyon sentetik önem ve iki ortak katkı maddelerinin mekanik bir rol göstermek için seçilmiştir. Sm-Barbier reaksiyon alkil halid, karbonil, Sm ve indirgeyici bir kap içinde aynı anda karıştırılır olan tek fark ile geleneksel Grignard reaksiyonu ile benzerdir. Bağlama ortağı arasında bir dizi ile Sm-aracılı Barbier reaksiyon 1,15 Örnekleri bildirilmiştir, 1,3,7,10,12 ve ut olmuşturbüyük doğal ürünlerin sentezi anahtar adım ilized. SMI 2 reaksiyon katkı maddelerin etkisi ile ilgili daha önceki çalışmalarda 16,17 HMPA daha güçlü bir üreten, samaryum metal koordinasyon merkezine göre SMI 2 indirgeme potansiyelini arttırır göstermiştir ki, 13-14,18 sterik indirgeyici 19-21 ipotekli ve Sm-Barbier sonraki reaksiyonda bağ-oluşturucu etkinlikler kolaylaştıran sonrası elektron transfer adımda bir tamamlayıcı bir rol oynar. 22 oynama bazı durumlarda, HMPA ayrıca alkil halid aktif hale getirmek için gösterilmiştir bir ön denge adımda bir kompleks oluşturarak. 23 Ni (II) tuzları, Sm-aracılı dönüşüm sıklıkla kullanılan bir katalizör eklenebilir. Başarısı için kritik olmasına rağmen 24-27, Ni (II) &#39;nin mekanistik rol bu tepkimeler de bilinmemektedir. Yakın zamanda, SMI 2 Ni (0) Ni (II) azalttığı gösterilmiştir, ve reaksiyon daha sonra organome yoluyla gerçekleştirilirtallic Ni (0) kimyası. 28. Bunlar, mekanik çalışmalar, aynı Barbier ürün elde edilmiş olmasına rağmen, SMI 2 reaksiyonu içinde farklı katkı maddelerinin kullanımı ile büyük ölçüde reaksiyon mekanistik yolu değiştirir olduğu görülmüştür. Bu SMI çalıştırmak için protokol 2-tepkimesi tarif edilmektedir.

Şekil 1, samaryum Barbier reaksiyon göstermektedir. Herhangi bir katkı maddesi ile birlikte Sm-aracılı reaksiyon 72 saat sürer; kalan kısmında ise başlangıç ​​maddeleri ile istenen ürün% 69 elde edilmiştir. 10 veya daha fazla eşi ilavesi ile. HMPA ve reaksiyon birkaç dakika içinde hemen hemen nicel ve tamam olmaktadır. 1 mol% Ni (acac) 2 eklenmesi ile 15,23, reaksiyon bir% 97 verim ile, 15 dakika içinde tamamlandı. 28 (HMPA) 4 - HMPA SMI 2, yardımcı solvent yerinden SMI 2 oluşturacak şekilde koordine THF eklenir. Hatta daha fazla HMPA (6-10 eşi.) Ilavesi ile, iyodür iyonu dış alan (Şekil 2) ile deplase olur. 19-21 mekanik çalışmalar HMPA Sm-Barbier tepki olarak kullanıldığı zaman da yardımcı solvent etkileşim göstermek alkil halojenür yüzey s aktive karbon-halide bağı uzatır karmaşık bir şekillendirme ilepecies Sm tarafından azaltma (Şekil 3) daha hassas hale getirir. HMPA, HMPA ile Sm-Barbier reaksiyon mekanizmasının Bu rollerin detaylı anlayış sayesinde (Şekil 4) önerilmiştir. 23 öncesi bir denge adımda oluşan alkil halojenür-HMPA kompleksi Sm / HMPA azalır oluşturmak için Adım tespit oranı radikaldir. Radikal karbonil ve protonasyon üzerinde çiftler nihai ürün verimleri organosamarium bir tür oluşturmak üzere daha da azaltılması uğrar. Ni (II) katkı maddesi söz konusu olduğunda, SMI 2 başlangıçta tercihen alt tabaka ya da azaltılması üzerinde Ni (0) Ni (II) azaltır. Kinetik ve mekanik çalışmalar sonucu aşağıdaki mekanizma (Şekil 5) öngörülmüştür. Bir organonikel türlerinin oluşumuna alkil halid bağ içine 28 SMI 2 tarafından düşürülmesinden sonra, çözünür Ni (0) tür ekler. Sm çok oxophilic doğası (III) ile tahrik<html> Geri katalitik döngü içine bir organosamarium ara bültenleri Ni (II) oluşturmak üzere transmetalasyon. Daha sonra organosamarium karbonil çiftler, ve protonasyon üzerine arzu edilen üçüncül alkol oluşturur. Aynı zamanda, Ni (0) nanopartiküllerin Ni Sm-aracılı azalma (II) ile oluşur olduğu görülmüştür, ancak bu parçacıklar atıl ve katalizör deaktivasyon kaynak olduğu bulunmuştur. <img alt="Şekil 1" fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig1highres.jpg" src="/files/ftp_upload/4323/4323fig1.jpg" /> Iodododecane ve 3-pentanon ile, Şekil 1. Samaryum Barbier reaksiyon. <img alt="Şekil 2," fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig2highres.jpg" src="/files/ftp_upload/4323/4323fig2.jpg" /> Şekil 2. SMI 2-HMPA kompleksi. ontent &quot;fo: keep-together.within-page =&quot; always &quot;&gt; <img alt="Şekil 3" fo:content-width="3.5in" fo:src="/files/ftp_upload/4323/4323fig3highres.jpg" src="/files/ftp_upload/4323/4323fig3.jpg" /> Şekil 3,. HMPA ve alkil iyodür kompleksi. <img alt="Şekil 4," fo:content-width="4.5in" fo:src="/files/ftp_upload/4323/4323fig4highres.jpg" src="/files/ftp_upload/4323/4323fig4.jpg" /> Şekil 4. Aşırı HMPA ile samaryum Barbier reaksiyon için önerilen mekanizma. <img alt="Şekil 5," fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig5highres.jpg" src="/files/ftp_upload/4323/4323fig5.jpg" /> Şekil 5,. Katalitik Ni (II) içeren samaryum Barbier reaksiyon için önerilen mekanizması.

Watch this Scientific Journal Video about Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction at JoVE.com

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

Samaryum diiodide hazırlanması için bir basit bir prosedür (SMI<sub&gt; 2</sub&gt;) THF içinde tarif edilmektedir. (Acac) yani heksametilfosforamid (HMPA) ve Ni iki ana katkı maddeleri rol<sub&gt; 2</sub&gt; Sm aracılı reaksiyonlar Sm-Barbier tepki gösterilmiştir.

Hazırlanması ve Samaryum Diiodide Kullanımı (SMI<sub&gt; 2</sub&gt;) In Organic Synthesis: Samaryum Barbier Reaksiyonu HMPA ve Ni (II) tuzlarının Mekanistik Rolü

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

32.6K Görüntüleme.  Lehigh University. Samaryum diiodide hazırlanması için bir basit bir prosedür (SMI 2) THF içinde tarif edilmektedir. (Acac) yani heksametilfosforamid (HMPA) ve Ni iki ana katkı maddeleri rol 2 Sm aracılı reaksiyonlar Sm-Barbier tepki gösterilmiştir.

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

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

The development of fluorescent indicators represented a revolution for life sciences. Genetically encoded and synthetic fluorophores with sensing abilities allowed the visualization of biologically relevant species with high spatial and temporal resolution. Synthetic dyes are of particular interest thanks to their high tunability and the wide range of measureable analytes. However, these molecules suffer several limitations related to small molecule behavior (poor solubility, difficulties in targeting, often no ratiometric imaging allowed). In this work we introduce the development of dendrimer-based sensors and present a procedure for pH measurement in vitro, in living cells and in vivo. We choose dendrimers as ideal platform for our sensors for their many desirable properties (monodispersity, tunable properties, multivalency) that made them a widely used scaffold for several biomedical devices. The conjugation of fluorescent pH indicators to the dendrimer scaffold led to an enhancement of their sensing performances. In particular dendrimers exhibit reduced cell leakage, improved intracellular targeting and allow ratiometric measurements. These novel sensors were successfully employed to measure pH in living HeLa cells and in vivo in mouse brain.

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Fluorescence sensors are powerful tools in life science. Here we describe a methodology to synthesize and use dendrimer-based fluorescent sensors to measure pH in living cells and in vivo. The dendritic scaffold enhances the properties of conjugated fluorescent dyes leading to improved sensing properties.

Sentez, Hücresel Teslimat ve<em&gt; In vivo</em&gt; Dendrimer tabanlı pH Sensörlerin Uygulamaları

The development of  fluorescent indicators represented a revolution for life sciences. Genetically  encoded and synthetic fluorophores with sensing ...

Kimya

Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. Isonicotinic acid, or its derivatives, are coupled to variable length diaminoalkane chains under an inert atmosphere in anhydrous DMF or DMSO with the use of a weak base, triethylamine, and a coupling agent, 1-propylphosphonic anhydride. The products precipitate from solution upon formation or can be precipitated by the addition of water. If desired, the ligands can be further purified by recrystallization from hot water. Dinuclear platinum complex synthesis using the bispyridine ligands is done in hot water using transplatin. The most informative of the chemical characterization techniques to determine the structure and gross purity of both the bispyridine ligands and the final platinum complexes is 1H NMR with particular analysis of the aromatic region of the spectra (7-9 ppm). The platinum complexes have potential application as anticancer agents and the synthesis method can be modified to produce trinuclear and other multinuclear complexes with different hydrogen bonding functionality in the bridging ligand.

This protocol describes the use of amide coupling reactions of isonicotinic acid and diaminoalkanes to form bridging ligands suitable for use in the synthesis of multinuclear platinum complexes, which combine aspects of the anticancer drugs BBR3464 and picoplatin.

Çekirdekli Antikanser Maddeleri olarak Platinum bispiridin tabanlı Ligandların ve kompleks Sentezlenmesi için kullanılan amid bağlantı reaksiyon

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. ...

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.

Fonksiyonlu Sentezi ve Karakterizasyonu Metal-organik Altyapıları

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

Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus

Here we present a protocol for the synthesis of two distinct carbonyl-decorated carbenes. Both carbenes can be prepared using nearly identical procedures in multi-gram scale quantities. The goal of this manuscript is to clearly detail how to handle and prepare these unique carbenes such that a synthetic chemist of any skill level can work with them. The two carbenes described are a diamidocarbene (DAC, carbene 1) and a monoamidoaminocarbene (MAAC 2). These carbenes are highly electron-deficient and as such display reactivity profiles that are atypical of more traditional N-heterocyclic carbenes. Additionally, these two carbenes only differ in their electrophilic character and not their steric parameters, making them ideal for studying how carbene electronics influence reactivity. To demonstrate this phenomenon, we are also describing the activation of white phosphorus (P4) using these carbenes. Depending on the carbene used, two very different phosphorus-containing compounds can be isolated. When the DAC 1 is used, a tris(phosphaalkenyl)phosphane can be isolated as the exclusive product. Remarkably however, when MAAC 2 is added to P4 under identical reaction conditions, an unexpected carbene-supported P8&#160;allotrope of phosphorus is isolated exclusively. Mechanistic studies demonstrate that this carbene-supported P8allotrope forms via a [2+2] cycloaddition dimerization of a transient diphosphene which has been trapped by treatment with 2,3-dimethyl-1,3-butadiene.

Here, we present a protocol for the synthesis of two carbonyl-decorated carbenes. The protocol makes these interesting compounds readily available to chemists of all skill levels. In addition to the synthesis of these two carbenes, their use in the activation of white phosphorus is also described.

Beyaz Fosfor harekete geçirmek Karbonil dekore Karbenlerin hazırlanması ve kullanımı

Here we present a protocol for the synthesis of two distinct carbonyl-decorated carbenes. Both carbenes can be prepared using nearly identical procedures ...

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.

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.

Asil klorür ve potasyum Alkynyltrifluoroborate Tuzlarından Ynones Metal içermeyen sentezi

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

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

Nanoboyutlu Monosodyum Titanate Sentezi ve Reaksiyon Kimya

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

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.

Supramoleküler Kolloidlerin Sentezi ve Karakterizasyonu

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

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the development of antibody drug conjugates (ADCs) and nanomedicine, fluorescent microscopy and systems chemistry. For many of these applications, specificity of the bioconjugation method used is of prime concern. The Michael addition of maleimides with cysteine(s) on the target proteins is highly selective and proceeds rapidly under mild conditions, making it one of the most popular methods for protein bioconjugation.
We demonstrate here the modification of the only surface-accessible cysteine residue on yeast cytochrome c with a ruthenium(II) bisterpyridine maleimide. The protein bioconjugation is verified by gel electrophoresis and purified by aqueous-based fast protein liquid chromatography in 27% yield of isolated protein material. Structural characterization with MALDI-TOF MS and UV-Vis is then used to verify that the bioconjugation is successful. The protocol shown here is easily applicable to other cysteine - maleimide coupling of proteins to other proteins, dyes, drugs or polymers.

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

This protocol details the important steps required for the bioconjugation of a cysteine containing protein to a maleimide, including reagent purification, reaction conditions, bioconjugate purification and bioconjugate characterization.

Protein Bioconjugatlar sentezi<em&gt; yoluyla</em&gt; Sistein-maleimid Kimya

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

Tek Molekül Düzeyde Halkalı Polimerlerin Sentezi ve eritin Devlet Onların Pasif Hareket Karakterizasyonu

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

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.

palladyum<em&gt; K</em&gt; -Heterosiklik Karben Kompleksleri: Benzimidazolyum Tuzlarından Sentez ve Karbon-karbon Bağ Oluşturma Reaksiyonlarında Katalitik Aktivite

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