Name: accessing valuable ligand supports for transition metals: a modified, intermediate scale preparation of 1,2,3,4,5-pentamethylcyclopentadiene
Uploaded: 2017-03-20T14:00:00
Description: Watch this Scientific Journal Video about Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene at JoVE.com

Vi er taknemmelige for National Science Foundation (CHE-1.300.508) og Mount St. Marys University (Start og Summer Faculty Development) for generøs støtte for dette arbejde. Ben Rupert (University of Delaware, massespektrometri Facility) er anerkendt for LIFDI massespektralanalyser.

1. Syntese af en isomer blanding af 3,4,5-trimethyl-2,5-heptadien-4-oler <ol><li> Fyld en ovntørret, 500 ml bægerglas med 200 ml hexaner og dække med en ovntørret urglas. <ol><li> I en tom hætte, bruge en ren saks til at klippe halv tomme stykker af lithium wire. Tør hver lithium brik på en papirserviet for at fjerne overskydende mineralolie, indtil al olien tilsyneladende fjernes fra metallets overflade, og anbring i bægeret indeholdende hexaner. </li><li> Fyld en ovntørret, 250 ml bægergla...

<ol>
	<li>Kealy, T. J., Pauson, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+type+of+organo-iron+compound.">A new type of organo-iron compound.</a> Nature. 168, 1039-1040 (1951).</li><li>Wilkinson, G., Rosenblum, M., Whiting, M. C., Woodward, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structure+of+iron+bis-cyclopentadienyl.">The structure of iron bis-cyclopentadienyl.</a> J. Am. Chem. Soc. 74, 2125-2126 (1952).</li><li>Fischer, E. O., Pfab, W. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclopentadien-Metallkomplexe,+ein+neuer+Typ+metallorganischer+Verbindungen.">Cyclopentadien-Metallkomplexe, ein neuer Typ metallorganischer Verbindungen.</a> Z. Naturforsch. 76, 377-379 (1952).</li><li>Pauson, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ferrocene-how+it+all+began.">Ferrocene-how it all began.</a> J. Organomet. Chem. 637-639, 3-6 (2001).</li><li>Lauher, J. W., Hoffmann, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+and+chemistry+of+bis(cyclopentadienyl)-MLn+complexes.">Structure and chemistry of bis(cyclopentadienyl)-MLn complexes.</a> J. Am. Chem. Soc. 98, 1729-1742 (1976).</li><li>Resa, I., Carmona, E., Gutierrez-Puebla, E., Monge, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decamethyldizincocene,+a+stable+compound+of+Zn(I)+with+a+Zn-Zn+bond.">Decamethyldizincocene, a stable compound of Zn(I) with a Zn-Zn bond.</a> Science. 305, 1136-1138 (2004).</li><li>Brintzinger, H., Bercaw, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nature+of+so-called+titanocene,+(C10H10Ti)2.">Nature of so-called titanocene, (C10H10Ti)2.</a> J. Am. Chem. Soc. 92, 6182-6185 (1970).</li><li>King, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Some+applications+of+metal+carbonyl+anions+in+the+synthesis+of+unusual+organometallic+compounds.">Some applications of metal carbonyl anions in the synthesis of unusual organometallic compounds.</a> Acc. Chem. Res. 3, 417-427 (1970).</li><li>Chirik, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Group+4+transition+metal+sandwich+complexes:+still+fresh+after+almost+60+years.">Group 4 transition metal sandwich complexes: still fresh after almost 60 years.</a> Organometallics. 29, 1500-1517 (2010).</li><li>Bengali, A. A., Schultz, R. H., Moore, C. B., Bergman, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+the+C-H+bonds+in+neopentane+and+neopentane-d12+by+(&#951;5-C5(CH3)5)Rh(CO)2:+Spectroscopic+and+temporal+resolution+of+rhodium-krypton+and+rhodium-alkane+complex+intermediates.">Activation of the C-H bonds in neopentane and neopentane-d12 by (&#951;5-C5(CH3)5)Rh(CO)2: Spectroscopic and temporal resolution of rhodium-krypton and rhodium-alkane complex intermediates.</a> J. Am. Chem. Soc. 116, 9585-9589 (1994).</li><li>Shima, T., Hu, S., Luo, G., Kang, X., Luo, Y., Hou, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dinitrogen+cleavage+and+hydrogenation+by+a+trinuclear+titanium+polyhydride+complex.">Dinitrogen cleavage and hydrogenation by a trinuclear titanium polyhydride complex.</a> Science. 340, 1549-1552 (2013).</li><li>Negishi, E. -. I., Takahashi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alkene+and+alkyne+complexes+of+zirconocene.+Their+preparation,+structure,+and+novel+transformations.">Alkene and alkyne complexes of zirconocene. Their preparation, structure, and novel transformations.</a> Bull. Chem. Soc. Jpn. 71, 755-769 (1998).</li><li>Rosenthal, U., Burlakov, V. V., Arndt, P., Baumann, W., Spannenberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+titancocene+complex+of+bis(trimethylsilyl)acetylene:+Synthesis,+structure,+and+chemistry.">The titancocene complex of bis(trimethylsilyl)acetylene: Synthesis, structure, and chemistry.</a> Organometallics. 22, 884-900 (2003).</li><li>Jordan, R. F., Bradley, P. K., LaPointe, R. E., Taylor, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cationic+zirconium+catalysts+for+carbon-carbon+bond+forming+chemistry.">Cationic zirconium catalysts for carbon-carbon bond forming chemistry.</a> New J. Chem. 14, 505-511 (1990).</li><li>Ewen, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Symmetry+rules+and+reaction+mechanisms+of+Ziegler-Natta+catalysts.">Symmetry rules and reaction mechanisms of Ziegler-Natta catalysts.</a> J. Mol. Catal. 128, 103-109 (1998).</li><li>Manriquez, J. M., Bercaw, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+a+dinitrogen+complex+of+bis(pentamethylcyclopentadienyl)zirconium(II).+Isolation+and+protonation+leading+to+the+stoichiometric+reduction+of+dinitrogen+to+hydrazine.">Preparation of a dinitrogen complex of bis(pentamethylcyclopentadienyl)zirconium(II). Isolation and protonation leading to the stoichiometric reduction of dinitrogen to hydrazine.</a> J. Am. Chem. Soc. 96, 6229-6230 (1974).</li><li>Brintzinger, H. H., Bercaw, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bis(pentamethylcyclopentadienyl)titanium(II).+Isolation+and+reactions+with+hydrogen,+nitrogen,+and+carbon+monoxide.">Bis(pentamethylcyclopentadienyl)titanium(II). Isolation and reactions with hydrogen, nitrogen, and carbon monoxide.</a> J. Am. Chem. Soc. 93, 2045-2046 (1971).</li><li>Lehman, M. C., Gary, J. B., Boyle, P. D., Sanford, M. S., Ison, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+solvent+and+ancillary+ligands+on+the+catalytic+H/D+exchange+reactivity+of+Cp*IrIII(L)+complexes.">Effect of solvent and ancillary ligands on the catalytic H/D exchange reactivity of Cp*IrIII(L) complexes.</a> ACS Catal. 3, 2304-2310 (2013).</li><li>Pitman, C. L., Finster, O. N. L., Miller, A. J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclopentadiene-mediated+hydride+transfer+from+rhodium+complexes.">Cyclopentadiene-mediated hydride transfer from rhodium complexes.</a> Chem. Commun. 52, 9105-9108 (2016).</li><li>Tarantino, K. T., Miller, D. C., Callon, T. A., Knowles, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bond-weakening+catalysis:+Conjugate+aminations+enabled+by+the+soft+homolysis+of+strong+N-H+bonds.">Bond-weakening catalysis: Conjugate aminations enabled by the soft homolysis of strong N-H bonds.</a> J. Am. Chem. Soc. 137, 6440-6443 (2015).</li><li>Bolig, A. D., Brookhart, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+sp3+C-H+bonds+with+cobalt(I):+Catalytic+synthesis+of+enamines.">Activation of sp3 C-H bonds with cobalt(I): Catalytic synthesis of enamines.</a> J. Am. Chem. Soc. 129, 14544-14545 (2007).</li><li>Hung-Low, F., Tye, J. W., Cheng, S., Bradley, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=sp2+C-H+activation+of+dimethyl+fumarate+by+a+[(Cp*Co)2-&#181;-(&#951;4:&#951;4-toluene)]+complex.">sp2 C-H activation of dimethyl fumarate by a [(Cp*Co)2-&#181;-(&#951;4:&#951;4-toluene)] complex.</a> Dalton Trans. 41 (26), 8190-8197 (2012).</li><li>Hung-Low, F., Krogman, J. P., Tye, J. W., Bradley, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+more+labile+low+electron+count+Co(I)+sources:+mild,+catalytic+functionalization+of+activated+alkanes+using+a+[(Cp*Co)2-&#181;-(&#951;4:&#951;4-arene)]+complex.">Development of more labile low electron count Co(I) sources: mild, catalytic functionalization of activated alkanes using a [(Cp*Co)2-&#181;-(&#951;4:&#951;4-arene)] complex.</a> Chem. Commun. 48 (3), 368-370 (2012).</li><li>Andjaba, J. M., Tye, J. W., Yu, P., Pappas, I., Bradley, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cp*Co(IPr):+synthesis+and+reactivity+of+an+unsaturated+Co(I)+complex.">Cp*Co(IPr): synthesis and reactivity of an unsaturated Co(I) complex.</a> Chem. Commun. 52, 2469-2472 (2016).</li><li>Fendrick, C. M., Schertz, L. D., Mintz, E. A., Marks, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+synthesis+of+1,2,3,4,5-pentamethylcyclpentadiene.">Large-scale synthesis of 1,2,3,4,5-pentamethylcyclpentadiene.</a> Inorg. Synth. 29, 193-198 (1992).</li><li>Threlkel, R. S., Bercaw, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Convenient+synthesis+of+alkyltetramethylcyclopentadienes+and+phenyltetramethylcyclopentadiene.">A Convenient synthesis of alkyltetramethylcyclopentadienes and phenyltetramethylcyclopentadiene.</a> J. Organomet. Chem. 136, 1-5 (1977).</li><li>Manriquez, J. M., Fagan, P. J., Schertz, L. D., Marks, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=1,2,3,4,5-pentamethylcyclopentadiene.">1,2,3,4,5-pentamethylcyclopentadiene.</a> Inorg Synth. 28, 317-320 (1990).</li><li>Threlkel, R. S., Bercaw, J. E., Seidler, P. F., Stryker, J. M., Bergman, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=1,2,3,4,5-pentamethylcyclopentadiene.">1,2,3,4,5-pentamethylcyclopentadiene.</a> Org. Synth. 65, (1987).</li><li>Koelle, U., Kossakowski, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Di-&#181;-chloro-bis[(&#951;5-pentachlororuthenium(III)],+[Cp*RuCl2]2+and+Di-&#181;-methoxo-bis(&#951;5-pentamethylcyclomethylcyclopentadienyl)+diruthenium(II),+[Cp*RuOMe]2.">Di-&#181;-chloro-bis[(&#951;5-pentachlororuthenium(III)], [Cp*RuCl2]2 and Di-&#181;-methoxo-bis(&#951;5-pentamethylcyclomethylcyclopentadienyl) diruthenium(II), [Cp*RuOMe]2.</a> Inorg. Synth. 29, 225-228 (1992).</li><li>White, C., Yates, A., Maitlis, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&#951;5-pentamethylcyclopentadienyl)rhodium+and+-iridium+compounds.">&#951;5-pentamethylcyclopentadienyl)rhodium and -iridium compounds.</a> Inorg. Synth. 29, 228-234 (1992).</li><li>Andersen, R. A., Blom, R., Boncella, J. M., Burns, C. J., Volden, H. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+thermal+average+molecular+structures+of+bis(pentamethylcyclopentadienyl)magnesium(II),+-calcium(II),+and+-ytterbium(II)+in+the+gas+phase.">The thermal average molecular structures of bis(pentamethylcyclopentadienyl)magnesium(II), -calcium(II), and -ytterbium(II) in the gas phase.</a> Acta Chem. Scand. 41A, 24-35 (1987).</li><li>Gross, J. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liquid+injection+field+desorption/ionization+of+reactive+transition+metal+complexes.">Liquid injection field desorption/ionization of reactive transition metal complexes.</a> Anal. Bioanal. Chem. 386 (1), 52-58 (2006).</li></ol>

Under fremstilling af heptadienol blandingen, er det vigtigt at rense lithium før initiering af reaktionen med 2-brom-2-buten. Dette opnås ved aftørring resterende mineralolie anvendes til opbevaring på papirservietter, til det punkt, at olien vises fuldt fjernes fra overfladen, og ved at opløse enhver resterende olie i bægerglasset af hexaner. De hexaner blev anvendt som modtaget og ikke yderligere tørret før anvendelse i fremgangsmåden. På grund af både stor skala af reaktionen og et overskud af lithium anv...

Siden opdagelsen og strukturel belysning af ferrocen i 1950&#39;erne, 1, 2, 3, 4 cyclopentadienyl (Cp) substitueret ligander har spillet en afgørende rolle i udviklingen af organometalliske kemi. Disse ligander har tjent som alsidige ophæng for en række metaller, hvilket fører til studier af usædvanlig struktur og limning, 5, 6, 7 aktiveringen og funktionalisering af små molekyler, 8, 9, 10, 11, 12, 13 og katalyse, herunder olefinpolymerisation. 14, 15 1,2, 3,4,5-pentamethylcyclopentadienyl (Cp *) anion har vist sig at være en særdeles værdifuld ligand i overgang og hovedgruppe metal kemi, som methylgrupperne give større beskyttelse steriske, øget elektron donation af anioniske ligand, og blokere potentielle aktivering af cyclopentadienylringen. 16, 17 Cp * ligand stadig relevant selv i dag, da anionen nylig er blevet udnyttet til at understøtte H / D udveksling af Ir (III), 18 hydrid overførsel af Rh, 19 og konjugerede dersøgelser medieret af Ti (III). 20 Vores interesse i Cp * liganden skyldes et ønske at få adgang reaktive kilder til cobalt (I) til anvendelse i lille molekyle aktivering. 21 Disse undersøgelser har resulteret i dannelsen af både Cp * Co I og Cp * Co I L (L = N-heterocykliske carben) ækvivalenter til brug i sp 3 ogsp 2 CH bond oxidativ addition. 22, 23, 24 Som adgang til vores Cp * Co (II) udgangsmaterialer nødvendiggøre betydelige mængder af 1,2,3,4,5-pentamethylcyclopentadiene, vi ønskede en multigram syntese af Cp * H, givet den betydelige kommercielle omkostninger ved ligand. øjeblikket findes to store fremgangsmåder til fremstilling af Cp * H, som hver frembyder den iboende tekniske udfordringer i stor målestok. En procedure udviklet af mærker og kolleger involverer en to-trins syntese af 2,3,4,5-tetramethylcyclopent-2-enon, efterfulgt af installationen af ​​den endelige methylgruppe hjælp methyllithium. 25 Syntesen er beskrevet i massivt omfang, ved hjælp af en 12 L reaktion fartøj og mekanisk omrøring, samtidig kræver vedvarende lav temperatur køling ved 0 ° C i fire dage. En alternativ procedure oprindeligt udvikletaf Bercaw og medarbejdere, 26 og senere tilpasset ved Marks, 27 anvender in situ generation af en alkenylgruppe lithium for nukleofilt angreb af ethylacetat for at fremstille en isomer blanding af 3,4,5-trimethyl-2,5-heptadien-4-oler efterfulgt af sur medieret cyklisering at tilvejebringe Cp * H. De indledende rapporter af denne metode blev udført på en stor (3-5 L) skala og krævede mekanisk omrøring. Desuden blev en signifikant overskud af lithium metal, der anvendes, komplicerer quenching og efterfølgende oparbejdning af de mellemliggende heptadienols. En efterfølgende revision af proceduren skaleres ned reaktionen og mængden af lithium, 28, men sikkert quenching af reaktionsblandingen stadig et problem. Reproducerbarhed i indledningen af ​​alkenyl lithium, skyldes forskelle i lithium kilde og renhed eller tørhed af 2-brom-2-buten reaktant er endvidere bemærkes bekymringer. På baggrund af disse problemer med de almindeligt anvendte procedurer for preparing Cp * H, vi kiggede på at udvikle bedre adgang til liganden på en mellemliggende skala (30-40 g), som ville omgå brug af speciale laboratorieglas og udstyr, forbedre reaktion reproducerbarhed og sikkerhed, og forenkle oparbejdning og ligand rensning. Her rapporterer vi, at syntese af 1,2,3,4,5-pentamethylcyclopentadiene, baseret på ændringer af den nuværende procedure udviklet af Bercaw og kolleger. Den reviderede syntese og oprensning af liganden udretter de vigtigste mål er skitseret ovenfor, medens de tillader adgang til betydelige mængder (39 g) Cp * H i godt udbytte (58%). Proceduren giver andre yderligere fordele, herunder en mere kontrolleret quench af overskydende lithium under produktionen af ​​de mellemliggende heptadienols og en forenklet isolering af Cp * H tilstrækkelig renhed til efterfølgende metallering med overgangsmetaller. For at demonstrere anvendeligheden af den fremstillede ligand, blev det brugt til at syntetisere to [Cp * MCL 2] 2 (M= Ir, Ru) komplekser. Den reviderede protokol skitseret nedenfor supplerer eksisterende procedurer og giver en enklere og mere tilgængelig indgang til kemien i en allestedsnærværende underordnet ligand støtte metalorganisk kemi.

<table border="0" cellpadding="0" cellspacing="0" width="573">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Materials</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Lithium wire (in mineral oil)</td>
			<td style="width:71px;">Aldrich</td>
			<td>278327-100G</td>
			<td style="width:167px;">&#62;98%</td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">2-bromo-2-butene (mixture of cis/trans isomers)</td>
			<td style="width:71px;">Acros</td>
			<td>200016-364&#160;&#160;</td>
			<td style="width:167px;">98%, dried over molecular sieves from an oven overnight before use</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Hexanes</td>
			<td style="width:71px;">Millipore</td>
			<td style="width:119px;">HX0299-3</td>
			<td style="width:167px;">GR ACS, used as received</td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">Ethyl actetate</td>
			<td style="width:71px;">Millipore</td>
			<td style="width:119px;">EX0240-3</td>
			<td style="width:167px;">GR ACS, dried over molecular sieves from an oven overnight before use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ammonium chloride</td>
			<td style="width:71px;">Aldrich</td>
			<td style="width:119px;">213330-2.5kg</td>
			<td style="width:167px;">ACS Reagent</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Diethyl ether</td>
			<td style="width:71px;">Millipore</td>
			<td style="width:119px;">EX0190-5</td>
			<td style="width:167px;">GR ACS, collected from a solvent purification system before use</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Magnesium sulfate</td>
			<td style="width:71px;">Aldrich</td>
			<td style="width:119px;">793612-500g</td>
			<td style="width:167px;">Anhydrous, reagent grade</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">p-toluene sulfonic acid monohydrate</td>
			<td style="width:71px;">Fisher</td>
			<td style="width:119px;">A320-500</td>
			<td style="width:167px;">ACS Certified</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sodium bicarbonate</td>
			<td style="width:71px;">Fisher</td>
			<td style="width:119px;">5233-500</td>
			<td style="width:167px;">ACS Certified</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sodium carbonate</td>
			<td style="width:71px;">Amresco</td>
			<td style="width:119px;">0585-500g</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Ruthenium (III) chloride trihydrate</td>
			<td style="width:71px;">Pressure Chemical</td>
			<td style="width:119px;">4750</td>
			<td style="width:167px;">40% Metal</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Iridium (III) chloride hydrate</td>
			<td style="width:71px;">Pressure Chemical</td>
			<td style="width:119px;">5730</td>
			<td style="width:167px;">53% Metal</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Methanol</td>
			<td style="width:71px;">Avantor</td>
			<td style="width:119px;">3016-22</td>
			<td style="width:167px;">AR ACS, distilled from Mg before use</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Pentane</td>
			<td style="width:71px;">J. T. Baker</td>
			<td style="width:119px;">T007-09</td>
			<td style="width:167px;">&#62;98%, dried with a solvent purification system before use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Chloroform-d</td>
			<td style="width:71px;">Aldrich</td>
			<td style="width:119px;">151823-150G</td>
			<td style="width:167px;">99.8 atom % D</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Molecular sieves 4&#197;&#160;</td>
			<td style="width:71px;">Aldrich</td>
			<td style="width:119px;">208590-1KG</td>
			<td style="width:167px;">dried in an oven at 140 &#176;C before use&#160;</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Celite 545</td>
			<td style="width:71px;">Acros</td>
			<td style="width:119px;">AC34967-0025</td>
			<td style="width:167px;">dried in an oven at 140 &#176;C before use&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Name</td>
			<td style="width:71px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Equipment</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Schlenk line, with vacuum and inert gas manifolds</td>
			<td style="width:71px;">Custom</td>
			<td style="width:119px;">NA</td>
			<td>Used in Preps 1-4</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Solvent transfer manifold</td>
			<td style="width:71px;">Chemglass</td>
			<td style="width:119px;">AF-0558-01</td>
			<td style="width:167px;">Used in 2.2</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Airfree filter funnel</td>
			<td style="width:71px;">Chemglass</td>
			<td style="width:119px;">AF-0542-22</td>
			<td style="width:167px;">Used in 3.1.3</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">Glovebox</td>
			<td style="width:71px;">Vacuum Atmospheres</td>
			<td style="width:119px;">OMNI</td>
			<td style="width:167px;">Used in 3.2.2</td>
		</tr>
	</tbody>
</table>

accessing valuable ligand supports for transition metals: a modified, intermediate scale preparation of 1,2,3,4,5-pentamethylcyclopentadiene

En pålidelig, udarbejdelse af 1,2,3,4,5-pentamethylcyclopentadiene (Cp * H) mellemliggende skala præsenteres, baseret på ændringer af eksisterende protokoller, der stammer fra den første 2-brom-2-buten lithiering efterfulgt af syre medieret dienol ringslutning . Den reviderede syntese og oprensning af liganden undgår anvendelsen af ​​mekanisk omrøring, medens der stadig tillades adgang til betydelige mængder (39 g) Cp * H i godt udbytte (58%). Proceduren giver andre yderligere fordele, herunder en mere kontrolleret quench af overskydende lithium under produktionen af ​​de mellemliggende heptadienols og en forenklet isolering af Cp * H af tilstrækkelig renhed til metallering med overgangsmetaller. Liganden blev efterfølgende anvendt til at syntetisere [Cp * MCL 2] 2 komplekser af både iridium og ruthenium at demonstrere anvendeligheden af Cp * H fremstillet og oprenset ved vores metode. Proceduren beskrevet heri giver væsentlige mængder af et allestedsnærværende accessoriske ligand support, der bruges i metalorganisk kemi og samtidig minimere behovet for specialiseret laboratorieudstyr, hvilket giver en enklere og mere tilgængelig indgang til kemien i 1,2,3,4,5-pentamethylcyclopentadiene.

Beskrevet ovenfor for Cp * H synteseprotokol beror på ændring af tretrins procedure udviklet af Bercaw og medarbejdere og modificeret af Marks (figur 1). Den luftfølsomme alkenyl lithium fremstilles in situ ud fra en blanding af cis- og trans-2-buten via en lithium / halogen udveksling reaktion og efterfølgende standset med ethylacetat til fremstilling af en isomer blanding af heptadienols. Blandingen kan anvendes uden yderligere rensning i...

Watch this Scientific Journal Video about Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene at JoVE.com

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

Pålidelig, udarbejdelse af 1,2,3,4,5-pentamethylcyclopentadiene (Cp * H) mellemliggende skala præsenteres. Den reviderede protokol til syntese og oprensning af liganden minimerer behovet for specialiseret laboratorieudstyr samtidig forenkle reaktion workups og produkt rensning. Anvendelse af Cp * H ved syntesen af [Cp * MCL 2] 2 komplekser (M = Ru, Ir) er også beskrevet.

Adgang Værdifuld ligand Understøtter for Overgangsmetaller: En modificeret, Intermediate Scale Udarbejdelse af 1,2,3,4,5-Pentamethylcyclopentadiene

A reliable, intermediate scale preparation of 1,2,3,4,5-pentamethylcyclopentadiene (Cp*H) is presented, based on modifications of existing protocols that ...

Research

Education

JoVE Journal

JoVE Core

Organic Chemistry

Chemistry

Unit 1

Reactions of Alkenes

SCIENTISTS IN ACTION

Bio-layer Interferometry for Measuring Kinetics of Protein-protein Interactions and Allosteric Ligand Effects

Bio-lags Interferometry til måling Kinetik af protein-protein interaktioner og allosteriske Ligand Effects

We describe the use of Bio-layer Interferometry to study inhibitory interactions of subunit &#949;&#160;with the catalytic complex of Escherichia ...

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS

Syntese af antiviral tetrahydrocarbazol Derivater af fotokemisk og Syre-katalyseret CH Funktionalisering via mellemliggende peroxider (chips)

The direct functionalization of C-H bonds is an important and long standing goal in organic chemistry. Such transformations can be very powerful in order ...

Transport of Surface-modified Carbon Nanotubes through a Soil Column

Transport af overflademodificeret kulstofnanorør gennem en Soil kolonne

Carbon nanotubes (CNTs) are widely manufactured nanoparticles, which are being utilized in a number of consumer products, such as sporting goods, ...

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix

Syntese af ligand-free CdS Nanopartikler inden en Sulfur copolymermatrix

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature ...

Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

Sulfat Separation ved selektiv krystallisation med en Bis-iminoguanidinium ligand

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, ...

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Udarbejdelse og evaluering af<sup&gt; 99m</sup&gt; Tc-mærket tridentat Chelater for Pre-targeting Brug Bioorthogonal Kemi

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the ...

Deposition of Porous Sorbents on Fabric Supports

Deposition af porøse Sorbents på stof understøtter

A microwave deposition technique for silanes, previously described for production of oleophobic fabrics, is adapted to provide a fabric support material ...

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Syntese og ydeevne beskrivelser af overgangen Metal enkelt Atom katalysator for elektrokemisk CO2 reduktion

This protocol presents both the synthesis method of the Ni single atom catalyst, and the electrochemical testing of its catalytic activity and selectivity ...

Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles

Ligand-medieret Nukleering og vækst af Palladium Metal nanopartikler

The size, size distribution and stability of colloidal nanoparticles are greatly affected by the presence of capping ligands. Despite the key contribution ...

Microfluidic Preparation of Liquid Crystalline Elastomer Actuators

Mikrofluid fremstilling af flydende krystallinske Elastomer aktuatorer

This paper focuses on the microfluidic process (and its parameters) to prepare actuating particles from liquid crystalline elastomers. The preparation ...