Name: preparation and use of carbonyl-decorated carbenes in the activation of white phosphorus
Uploaded: 2014-10-03T15:00:00.000+00:00
Duration: 14 min 7 s
Description: Watch this Scientific Journal Video about Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus at JoVE.com

We are grateful to the Research Corporation for Science Advancement (20092), the National Science Foundation (CHE-1362140), and Texas State University for their generous support.

1，合成Diamidocarbene（化合物1） <ol><li>烘箱干燥的100ml Schlenk烧瓶中，连接到一个高性能的真空歧管，抽真空，并用氮气冲洗。添加搅拌棒的烧瓶中，并盖用橡胶隔膜。称出N，N&#39;-dimesitylformamidine 12（1.5克，5.35毫摩尔），并将其添加到该烧瓶中，同时用氮气冲洗。 <ol><li>加入（通过干的脱氧的注射器）30ml无水，脱气的二氯甲烷（DCM），随后加入三乙胺（1.1毫升，8.0毫摩尔，1.5当量）。冷却，在冰浴将得到的溶液至0℃。 </li><li> （通过一个干的脱氧的注射器）dimethylmalonyl氯化物逐滴加入（0.75毫升，5.60毫摩尔，1.05当量）冷却的溶液中。在此外，让溶液在氮气气氛下搅拌，在0℃下搅拌1小时。一旦溶液搅拌1小时，除去真空下所有的挥发性物质。 </li><li>添加干燥脱气己烷的混合溶剂:DCM（2:1（体积），24毫升总体积），以在反应烧瓶中的残余物。让该混合物磨碎10分钟。 </li><li>同时，附装有介质的孔隙率的玻璃料，以烘箱干燥的100ml Schlenk烧瓶的顶部有一个过滤管（参见图1）。要过滤管，补充足够的烘干硅藻土来创建一个过滤器插件约2英寸高。密封该过滤筒用橡胶隔膜，并通过附加的Schlenk烧瓶中，真空腔抽真空，在系统上。 <img alt="图1" fo:content-width="2.5in" src="/files/ftp_upload/52149/52149fig1highres.jpg" width="250" /> 图1过滤装置组件，用于从碳烯的前体1-HCl和2 -盐酸除去的[HNEt 3] [氯]，该装置也可以用来除去NaCl卡宾1和2的合成过程中形成的。 </li><li>过滤装置组件，用于从碳烯的前体1-HCl和2 -盐酸除去的[HNEt 3] [氯]。该设备也是我们编辑删除卡宾1和2的合成过程中盐形成。 </li><li>一旦过滤装置已经组装并在真空条件下，通过套管转移的白色悬浮液在反应烧瓶中放入滤管。一定要定期地拉真空上收集的Schlenk烧瓶以确保所有的溶液过滤通过硅藻土。 </li><li>通过橡胶隔膜用注射器（1，体积加入18ml总体积2）:通过将干的，脱气的己烷的混合溶剂洗涤硅藻土DCM中。再次，定期地拉在收集的Schlenk烧瓶中的真空，以确保所有的溶液过滤通过硅藻土。 </li><li>断开过滤管的集合Schlenk烧瓶中在氮气的冲洗，然后密封收集Schlenk烧瓶用玻璃塞。除去所有在真空下从采集的Schlenk烧瓶中的溶剂，得到的前体diamidocarbene 1（1-HCl）的作为空气/湿气敏感的白色粉末在大约92％收益率（2.04克）。该产品可以通过1 H和13 C NMR谱（CDCL 3）13,14进行验证。转移化合物1盐酸成之前的下一个步骤存储的手套箱中。 </li></ol></li><li>为了准备diamidocarbene 1，首先转移烘箱干燥的100ml Schlenk烧瓶中搅拌棒和玻璃塞成一个充满氮气的手套箱。 <ol><li>称取卡宾前体1 - 盐酸（0.600克，1.45 mmol）和六甲基二硅钠（加入NaHMDS，0.267克，1.46毫摩尔），并将这两个固体放入Schlenk烧瓶。 </li></ol></li><li>添加干燥，脱气的苯（25毫升）中的两种固体中的Schlenk烧瓶中，然后塞住烧瓶。在这一点上，该Schlenk烧瓶从手套箱中取出。 </li><li>搅拌该卡宾在RT的溶液30分钟。在整个反应过程中，溶液会变成混浊的橙黄色。在这段时间内，建立类似于上面所描述的（使用1 I的过滤装置硅藻土NCH插头）为1的HCl的合成。 </li><li>过滤卡宾溶液（以除去沉淀的NaCl）中所描述的前体1-HCl中。一旦溶液被过滤，除去所有使用真空，得到粗卡宾1，其为黄色 - 橙色粉末的挥发物。通过洗涤该固体用冷的己烷（约10毫升），得到分析纯的化合物作为空气/湿气敏感的白色粉末在大约85％的产率（0.462克）进一步纯化卡宾1。 1 H和13 C-NMR光谱（C 6 D 6）13验证产品。 </li></ol> 2，合成Monoamidocarbene（化合物2） <ol><li>烘箱干燥250毫升Schlenk烧瓶连接到一个高性能的真空歧管，抽真空，并用氮气冲洗。添加搅拌棒的烧瓶中，并盖用橡胶隔膜。称出N，N&#39;-dimesitylformamidine（3.00克，10.70毫摩尔），并将其添加到该烧瓶中，同时用氮气冲洗。 <ol><li>添加（六干的脱氧的注射器）125毫升干燥，脱气的DCM随后加入三乙胺（2.25毫升，16.05毫摩尔，1.5当量）。冷却，在冰浴将得到的溶液至0℃。 </li><li> （通过一个干的脱氧的注射器），3 - 氯代磺酰氯逐滴加入（1.54毫升，11.77毫摩尔，1.1当量）到冷却的溶液中。在此外，让溶液在氮气气氛下搅拌，在0℃下进行30分钟。然后逐渐温热溶液至室温，然后在真空下除去所有挥发性物质。除去溶剂后，将白色固体残留物会留。 </li><li>加入甲苯（200ml）中的白色固体，并允许该悬浮液，以磨碎1小时。然后经硅藻土过滤的使用中孔玻璃上的1英寸插头混合物布氏漏斗。 </li><li>甲苯溶液转移至500ml圆底烧瓶中搅拌棒。连接回流冷凝器的烧瓶中，并加热该溶液至回流（110℃）16小时。在çourse反应，生成白色沉淀就会形成。 </li><li> 16小时后，使悬浮液冷却至室温。在这段时间内，更坚实将沉淀从溶液中。收集经真空过滤固体并洗涤固体用冷甲苯（3×20毫升）。 </li><li>干燥得到的白色，使用真空固体，得到约91％的产率（3.32 G）的前体monoamidocarbene 2（2-HCl）的作为空气稳定的白色粉末。该产品可以通过1 H和13 C NMR谱（CDCL 3）15进行验证。转移化合物2的HCl转化为之前的下一个步骤存储的手套箱中。 </li></ol></li><li>要准备monoamidocarbene 2，第一转移烘箱干燥的100ml Schlenk烧瓶中搅拌棒和玻璃塞成一个充满氮气的手套箱。 <ol><li>称取卡宾前体2 - 盐酸（0.500克，1.25毫摩尔），并加入NaHMDS（0.241克，1.32毫摩尔），并将这两种固体放入Schlenk烧瓶。 </li><li>添加干燥，脱气苯（45毫升）中的两种固体中的Schlenk烧瓶中，然后塞住烧瓶。在这一点上，该Schlenk烧瓶从手套箱中取出。 </li><li>搅拌该卡宾在RT的溶液30分钟。在反应过程中，溶液会变成混浊的黄色。同时，设置了类似于上述的1-HCl中使用硅藻土1英寸插头合成一个的过滤装置。 </li><li>过滤卡宾溶液（以除去沉淀的NaCl）中所描述的卡宾1一旦溶液被过滤，除去所有使用真空，得到粗卡宾2为褐色粉末的挥发物。通过反复洗涤该固体，用戊烷，得到分析纯的化合物作为空气/湿气敏感的白色粉末在大约62％的产率（0.309克）进一步纯化卡宾2。 1 H和13 C-NMR光谱（C 6 D 6）15验证产品。 </li></ol></li></ol> 3，合成三（phosphaalkenyl）膦（化合物3） 警告声明:白磷是极其引火以及有毒的，应在手套箱谨慎处理只要有可能。 <ol><li>为了使三（phosphaalkenyl）膦（化合物3），称出diamidocarbene 1（0.100克，0.266毫摩尔，3当量）和白色磷（P 4 0.011克，0.089毫摩尔，1当量）在含氮内与灯填充的手套箱关闭。在这前几步为P 4对光敏感关闭尽可能多的灯在实验室。 </li><li>两个固体添加到被包裹在铝箔20毫升玻璃小瓶中。添加干燥，脱气的二乙醚（Et 2 O等，10ml）加 ​​到该固体，然后盖上小瓶。搅拌在黑暗中的淤浆搅拌2小时。在反应过程中，一个明亮的橙红色沉淀就​​会形成。 </li><li>通过使用10ml的中孔玻璃过滤分离出红色固体布氏漏斗。日洗e红色固体用Et 2 O（4×5ml）中，然后干燥在真空下，得到化合物3为分析纯的空气稳定的化合物在约82％的产率，0.092克（基于P 4）。 1 H和31 P NMR光谱（C 6 D 6）11验证产品。 </li></ol> 4，合成卡宾稳定P 8同素异形体（化合物4） <ol><li>方法A <ol><li>使卡宾稳定P 8同素异形体（化合物4），称出monoamidocarbene 2（0.100g克，0.276毫摩尔，3当量）和P 4（11.4毫克，0.092毫摩尔，1当量）在氮气填充的手套箱内与灯盒被关闭。在这前几步为P 4对光敏感关闭尽可能多的灯在实验室。 </li><li>两个固体添加到被包裹在铝箔20毫升玻璃小瓶中。添加干燥，脱气的二乙醚（Et 2 O等，10ml）加 ​​到该固体，然后盖上小瓶。当此外，乙醚，流年暗绿色的颜色变化迅速，以明亮的橙色。搅拌在黑暗中的淤浆搅拌2小时。在反应过程中，一个明亮的橙色沉淀就会形成。 </li><li>通过使用10ml的中孔玻璃过滤分离出橙色固体布氏漏斗。用Et 2 O（4×2毫升）洗涤橙色固体，然后干燥在真空下，得到化合物4作为与分析纯的空气稳定的化合物在约51％的产率，39.5毫克（基于P 4）。通过1 H和31 P NMR光谱（THF-D8）11确认该产品。 </li></ol></li><li>方法B <ol><li>称出monoamidocarbene 2（0.100g克，0.276毫摩尔，2当量）和P 4（17.1毫克，0.138毫摩尔，1当量）与灯充满氮气的手套箱内截止。在这前几步为P 4对光敏感关闭尽可能多的灯在实验室。 </li><li>经由两种固体加入到20ml的玻璃升被包裹在铝箔。添加干燥，脱气的己烷（10ml）加到该固体，然后盖上小瓶。在加入乙醚，流年暗绿色的颜色变化迅速，以明亮的橙色。搅拌在黑暗中的淤浆搅拌2小时。在反应过程中，一个明亮的橙色沉淀就会形成。 </li><li>使用10毫升培养基的孔隙率多孔玻璃布氏漏斗通过过滤分离出橙色固体，然后干燥在真空下，得到化合物4作为与分析纯的空气稳定的化合物在约75％的产率，87.7毫克（基于P 4）。通过1 H和31 P NMR光谱（THF-D8）验证产品11 </li></ol></li></ol>合成化合物5:5，通过[4 +2]环加成捕获瞬态Ë-1,2 -二（phosphaalkenyl）diphosphene <ol><li>以制备化合物5中，称出monoamidocarbene 2（0.300mL克，0.828毫摩尔，2当量）和P 4（51.3毫克，0.414毫摩尔，1当量） 九月另行购买的灯充满氮气的手套箱内截止。在这前几步为P 4对光敏感关闭尽可能多的灯在实验室。 </li><li>在P 4添加到20ml的玻璃瓶中，然后添加干燥，脱气的己烷溶液（18毫升）的小瓶中。接着，在己烷中添加2,3 -二甲基-1,3 -丁二烯（2毫升）到P 4的悬浮液。 </li><li>而己烷/ P 4的悬浮液快速搅拌下，在一个部分中添加卡宾2，为固体。受瞬间变成亮黄色。过了一段约10分钟，所有的固体会溶解之后的亮黄色固体沉淀。在这一点上，让该悬浮液搅拌4小时。 </li><li> 4小时后，用10毫升培养基的孔隙率多孔玻璃布氏漏斗通过过滤分离出黄色固体。此黄色固体为化合物5（纯度&gt; 90％由两个1 H和31 P NMR）。集中黄色清液至干并结合黄色残余物用过滤的黄色固体。 </li><li>为了净化化合物5，重结晶合并黄色固体从1:3（体积比）的DCM:己烷液（1​​2mL总体积），在-30℃的手套箱O 2 / N C冰箱。这个过程将得到5为分析纯的空气稳定的黄色晶体在约71％的产率，0.301克（基于P 4）。 1 H和31 P NMR光谱（C 6 D 6）11验证产品。 </li></ol>

<ol>
	<li>Di&#769;ez-Gonza&#769;lez, S., Marion, N., Nolan, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=N-Heterocyclic+Carbenes+in+Late+Transition+Metal+Catalysis.">N-Heterocyclic Carbenes in Late Transition Metal Catalysis.</a> Chem. Rev. 109, 3612-3676 (2009).</li><li>Enders, D., Niemeier, O., Henseler, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organocatalysis+by+N-Heterocyclic+Carbenes.">Organocatalysis by N-Heterocyclic Carbenes.</a> Chem. Rev. 107, 5606-5655 (2007).</li><li>Boydston, A. J., Williams, K. A., Bielawski, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Modular+Approach+to+Main-Chain+Organometallic+Polymers.">A Modular Approach to Main-Chain Organometallic Polymers.</a> J. Am. Chem. Soc. 127, 12496-12497 (2005).</li><li>Kamplain, J. W., Bielawski, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+covalent+polymers+based+upon+carbene+dimerization.">Dynamic covalent polymers based upon carbene dimerization.</a> Chem. Commun. , 1727-1729 (2006).</li><li>Back, O., Kuchenbeiser, G., Donnadieu, B., Bertrand, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Nonmetal-Mediated Fragmentation of P4: Isolation of P1and P2Bis(carbene). 48, 5530-5533 (2009).</li><li>Masuda, J. D., Schoeller, W. W., Donnadieu, B., Bertrand, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Carbene Activation of P4 and Subsequent Derivatization. 46, 7052-7055 (2007).</li><li>Masuda, J. D., Schoeller, W. W., Donnadieu, B., Bertrand, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NHC-Mediated+Aggregation+of+P4:+Isolation+of+a+P12+Cluster..">NHC-Mediated Aggregation of P4: Isolation of a P12 Cluster..</a> J. Am. Chem. Soc. 129, 14180-14181 (2007).</li><li>Wang, Y., 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=Carbene-Stabilized+Diphosphorus.">Carbene-Stabilized Diphosphorus.</a> J. Am. Chem. Soc. 130, 14970-14971 (1021).</li><li>Wang, Y., 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=Carbene-Stabilized+Parent+Phosphinidene+Organometallics.">Carbene-Stabilized Parent Phosphinidene Organometallics.</a> 29, 4778-4780 (2010).</li><li>Back, O., Donnadieu, B., Parameswaran, P., Frenking, G., Bertrand, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+crystalline+carbene-stabilized+P2-radical+cations+and+P2-dications.">Isolation of crystalline carbene-stabilized P2-radical cations and P2-dications.</a> Nature Chemistry. 2, 369-373 (2010).</li><li>Dorsey, C. L., Squires, B. M., Hudnall, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Isolation of a Neutral P8 Cluster by [2+2] Cycloaddition of a Diphosphene Facilitated by Carbene Activation of White Phosphorus. 52, 4462-4465 (2013).</li><li>Kuhn, K. M., Grubbs, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Facile+Preparation+of+Imidazolinium+Chlorides.">A Facile Preparation of Imidazolinium Chlorides.</a> Org. Lett. 10, 2075-2077 (2008).</li><li>Hudnall, T. W., Moerdyk, J. P., Bielawski, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonia+N-H+activation+by+a+N,N'-diamidocarbene.">Ammonia N-H activation by a N,N'-diamidocarbene.</a> Chem. Commun. 46, 4288-4290 (2010).</li><li>Lugan, N., Lavigne, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reprogramming+of+a+Malonic+N-Heterocyclic+Carbene:+A+Simple+Backbone+Modification+with+Dramatic+Consequences+on+the+Ligand's+Donor+Properties.">Reprogramming of a Malonic N-Heterocyclic Carbene: A Simple Backbone Modification with Dramatic Consequences on the Ligand's Donor Properties.</a> Eur. J. Inorg. Chem. 3, 361-365 (2010).</li><li>Blake, G. A., Moerdyk, J. P., Bielawski, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuning+the+Electronic+Properties+of+Carbenes:+A+Systematic+Comparison+of+Neighboring+Amino+versus+Amido+Groups.">Tuning the Electronic Properties of Carbenes: A Systematic Comparison of Neighboring Amino versus Amido Groups.</a> Organometallics. 31, 3373-3378 (2012).</li><li>Martin, C. D., Weinstein, C. M., Moore, C. E., Rheingold, A. L., Bertrand, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exploring+the+reactivity+of+white+phosphorus+with+electrophilic+carbenes:+synthesis+of+a+P4+cage+and+P8+clusters.">Exploring the reactivity of white phosphorus with electrophilic carbenes: synthesis of a P4 cage and P8 clusters.</a> Chem. Commun. 49, 4486-4488 (2013).</li></ol>

The authors have nothing to disclose.

一个直接的方法生成羰基饰卡宾及其应用白磷激活在这里提出。用于合成卡宾在协议中关键的步骤是:（一）确保所有溶剂在使用前进行适当干燥，（二）确保除酰氯的甲脒是做得很慢，（c）如果是硅藻土不烘箱干燥最少12小时的在180℃下，在1 -HCl的水解以及卡宾1和2发生。在一些情况下，白磷将转换为红磷。对于P 4的活化反应中，至关重要的是，该?...

稳定的卡宾已成为无处不在的试剂均相催化1，2有机催化，材料科学3,4，最近主族化学5-9。在后者的情况下，稳定的卡宾最近已被用在白色的磷（P 4）5-9的活化和官能化。直接转换P 4成的有机磷化合物的能力已成为一个热门的研究目标，努力开发出规避使用氯化或oxychlorinated磷前体"更绿色"的方法。尽管它们的广泛使用，配制和操作卡宾和活性化合物，如对4的可能是一个艰巨的任务。为此，我们编写了这份手稿，以提供清晰，简明的协议，将允许所有技能水平的合成化学家合成和操作两个非常独特的稳定çarbenes。此外，P 4的使用所描述的卡宾活化是详细的。 在此我们详细的协议为两缺电子的羰基饰卡宾的合成。我们选择这些卡宾，因为他们在电性能的唯一区别，而不是他们的立体参数，使它们非常适合学习的反应卡宾电子产品的影响。卡宾电子方面的反应性的重要性是由已报道由伯特兰和Robinson 5,8通式卡宾-P 2 -carbene的两个类似的化合物举例说明。贝特朗的P 2衍生物是由两个环状烷基氨基卡宾（民航）配位体的支持，并且在结构上，photophysically，并且比鲁宾逊的化合物，它是由两个N-杂环卡宾（的NHCs）5,8支承的P 2片段电化学不同。事实上，贝特朗的P 2 </子&gt;络合物的特征在于，其为黄色固体，具有碳烯 - 对 - 磷双键在固体状态，而报道罗宾逊的衍生物是一种暗红色固体，它包含NHC→第配价键。这种结构上的差异也表现电化学使得鲁宾逊的化合物中含有较多的富电子的磷中心，可以进行相反贝特朗的化合物可逆1或2电子氧化作用，它只能进行单一的可逆氧化10。 基于上述研究，我们的极大兴趣，学习P 4使用高电diamido-和monoamidoamino卡宾，以确定是否磷小说卡宾稳定的同素异形体，可以准备激活。我们专注于diamidocarbene（DAC）1，和monoamidoamino卡宾（MAAC）2只在各自electrophilicities有差异，以interrog吃了P 4活化什么样的角色卡宾电子游戏。有趣的是，当多电DAC的情况下，三（phosphaalkenyl）膦（3）可以被分离为专属产物，而当MAAC时，卡宾稳定P 8同素异形体（4），可以得到11。我们还询问机制形成（4），并发现它是通过[2 +2] cylcoaddition二聚化的过渡diphosphene的反应而形成的。本diphosphene的存在通过用2,3 -二甲基-1,3 -丁二烯诱捕它提供的[4 +2]环加成加合物5证实。该协议用 ​​于合成这些羰装饰卡宾和其相应的P 4活化的化合物本文描述了。

<table><tbody><tr><td>2,4,6-Trimethylaniline</td><td>Alfa Aesar</td><td>AAA13049-0E</td><td>98%</td></tr><tr><td>Triethylorthoformate</td><td>Alfa Aesar</td><td>AAA13587</td><td>98%</td></tr><tr><td>Dimethylmalonyl dichloride</td><td>TCI</td><td>D2723</td><td>&gt;98%</td></tr><tr><td>3-Chloro-pivaloyl chloride</td><td>Aldrich</td><td>225703-25G</td><td>98%</td></tr><tr><td>Triethylamine</td><td>Alfa Aesar</td><td>AAA12646</td><td>Stored over dried, activated 3 &amp;Aring; molecular sieves</td></tr><tr><td>Celite&amp;trade; 545</td><td>EMD</td><td>CX0574-3D</td><td>Oven-dried at 180 &amp;deg;C for a minimum of 12 hr</td></tr><tr><td>Sodium hexamethyldisilazide</td><td>Across</td><td>200014-462</td><td>95+%</td></tr><tr><td>2,3-Dimethyl-1,3-butadiene</td><td>Alfa Aesar</td><td>AAAL04207-09</td><td>98%</td></tr><tr><td>Dichloromethane</td><td>EMD</td><td>DX0835-5</td><td>Purified through solvent purification system, or standard methods</td></tr><tr><td>Tetrahydrofuran</td><td>Mallinckrodt</td><td>8498-09</td><td>Purified through solvent purification system, or standard methods</td></tr><tr><td>Hexanes</td><td>EMD</td><td>HX0299-3</td><td>Purified through solvent purification system, or standard methods</td></tr><tr><td>Benzene</td><td>EMD</td><td>BX0220-5</td><td>Purified through solvent purification system, or standard methods</td></tr><tr><td>Toluene</td><td>BDH</td><td>1151-19L</td><td>Purified through solvent purification system, or standard methods</td></tr><tr><td>White phosphorus</td><td>Generously donated from the Texas A&amp;amp;M chemistry store room.</td><td></td><td>Purified through sublimation and transferred directly into a glovebox while under vacuum in the sublimator</td></tr></tbody></table>

preparation and use of carbonyl-decorated carbenes in the activation of white phosphorus

在这里，我们提出了一个协议，两个不同的羰基饰卡宾的合成。两个卡宾可以使用多克规模的量几乎相同的方法来制备。这个手稿的目标是明确的细节如何处理，并准备这些独特的卡宾，使得任何技术水平的合成化学家能够与他们合作。描述这两个卡宾是一个diamidocarbene（DAC，卡宾1）和monoamidoaminocarbene（MAAC 2）。这些卡宾是高度缺电子，因此显示反应曲线是非典型的较传统的N-杂环卡宾。此外，这两个卡宾的区别仅在于它们的电性质，而不是其空间的参数，使它们非常适合用于研究电子的影响力如何卡宾反应。为了证明这个现象，我们也描述了使用这些卡宾白色磷（P 4）激活。根据carbenë使用两个非常不同的含磷化合物可被分离。当DAC 1的情况下，三（phosphaalkenyl）膦可被分离为专属产物。显着然而，当MAAC 2加入到P 4在相同的反应条件下，磷的一个意想不到的卡宾负载P 8同素异形体是完全隔离的。机制研究表明，通过瞬时diphosphene已捕获通过用2,3 -二甲基-1,3 -丁二烯的[2 +2]环加成二聚化此碳烯-支持P 8同素异形体的形式。

以分离三（phosphaalkenyl）膦，如3或从白磷在P 8 -allotrope（4）的能力依赖于使用的电卡宾的激活P 4四面体11,16。因此，重要的是，制备卡宾具有增强的π-酸，并通过扩展电性， 图2示出了卡宾前体1的HCl和其后续的脱质子化的合成，得到diamidocarbene 1 13。 diamidocarbene 1的合成中，可以实现在单一...

Watch this Scientific Journal Video about Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus at JoVE.com

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

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.

羰基饰卡宾的白色磷的活化制备方法和用途

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

preparation-use-carbonyl-decorated-carbenes-activation-white

Research

JoVE Journal

Chemistry

13.6K 次观看.  Texas State University. 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.

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

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions

Dichloro-bis(aminophosphine) complexes of palladium with the general formula of [(P{(NC5H10)3-n(C6H11)n})2Pd(Cl)2] (where n = 0-2), belong to a new family of easy accessible, very cheap, and air stable, but highly active and universally applicable C-C cross-coupling catalysts with an excellent functional group tolerance. Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium [(P(NC5H10)3)2Pd(Cl)2] (1), the least stable complex within this series towards protons; e.g. in the form of water, allows an eased nanoparticle formation and hence, proved to be the most active Heck catalyst within this series at 100 &#176;C and is a very rare example of an effective and versatile catalyst system that efficiently operates under mild reaction conditions. Rapid and complete catalyst degradation under work-up conditions into phosphonates, piperidinium salts and other, palladium-containing decomposition products assure an easy separation of the coupling products from catalyst and ligands. The facile, cheap, and rapid synthesis of 1,1',1"-(phosphinetriyl)tripiperidine and 1 respectively, the simple and convenient use as well as its excellent catalytic performance in the Heck reaction at 100 &#176;C make 1 to one of the most attractive and greenest Heck catalysts available.
We provide here the visualized protocols for the ligand and catalyst syntheses as well as the reaction protocol for Heck reactions performed at 10 mmol scale at 100 &#176;C and show that this catalyst is suitable for its use in organic syntheses.

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium [(P(NC5H10)3)2Pd(Cl)2] (1) is an easy accessible, cheap, and air stable, but highly active Heck catalyst with an excellent functional group tolerance that efficiently operates under mild reaction conditions to give the coupling products in very high yields.

Mizoroki-哎呀交叉偶联反应由二氯{双[1,1&#39;，1&#39;&#39;  - （phosphinetriyl）tripiperidine]}钯催化在温和的反应条件

Dichloro-bis(aminophosphine) complexes of palladium with the general formula of [(P{(NC5H10)3-n(C6H11)n})2Pd(Cl)2] (where n = 0-2), belong to a new family ...

科研

化学

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The silica-encapsulated metal oxide nanoparticles are then carburized in a methane/hydrogen atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal carbide nanoparticles. During the carburization process, the silica shells prevent the sintering of adjacent carbide nanoparticles while also preventing the deposition of excess surface carbon. Alternatively, the silica-encapsulated metal oxide nanoparticles can be nitridized in an ammonia atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal nitride nanoparticles. By adjusting the reverse microemulsion parameters, the thickness of the silica shells, and the carburization/nitridation conditions, the transition metal carbide or nitride nanoparticles can be tuned to various sizes, compositions, and crystal phases. After carburization or nitridation, the silica shells are then removed using either a room-temperature aqueous ammonium bifluoride solution or a 0.1 to 0.5 M NaOH solution at 40-60 &#176;C. While the silica shells are dissolving, a high surface area support, such as carbon black, can be added to these solutions to obtain supported early transition metal carbide or nitride nanoparticles. If no high surface area support is added, then the nanoparticles can be stored as a nanodispersion or centrifuged to obtain a nanopowder.

A &#8220;removable ceramic coating method&#8221; is presented in visual format for the synthesis of non-sintered and metal-terminated monometallic and bimetallic early transition metal carbide and nitride nanoparticles with tunable sizes and crystal structures.

单金属和双金属前过渡金属碳化物和氮化物纳米粒子的反相微乳液介导的合成

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The ...

Preparation of Carbon Nanosheets at Room Temperature

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into defined aggregates in aqueous media and at the air-water interface. In the aggregated state, the oligoynes can then be carbonized under mild conditions while preserving the morphology and the embedded chemical functionalization. This novel approach provides direct access to functionalized carbon nanomaterials. In this article, we present a synthetic approach that allows us to prepare hexayne carboxylate amphiphiles as carbon-rich siblings of typical fatty acid esters through a series of repeated bromination and Negishi-type cross-coupling reactions. The obtained compounds are designed to self-assemble into monolayers at the air-water interface, and we show how this can be achieved in a Langmuir trough. Thus, compression of the molecules at the air-water interface triggers the film formation and leads to a densely packed layer of the molecules. The complete carbonization of the films at the air-water interface is then accomplished by cross-linking of the hexayne layer at room temperature, using UV irradiation as a mild external stimulus. The changes in the layer during this process can be monitored with the help of infrared reflection-absorption spectroscopy and Brewster angle microscopy. Moreover, a transfer of the carbonized films onto solid substrates by the Langmuir-Blodgett technique has enabled us to prove that they were carbon nanosheets with lateral dimensions on the order of centimeters.

We present the synthesis of an amphiphilic hexayne and its use in the preparation of carbon nanosheets at the air-water interface from a self-assembled monolayer of these reactive, carbon-rich molecular precursors.

碳纳米片在室温下准备

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into ...

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.

钯<em&gt;ñ</em&gt; - 杂环碳烯配合物:苯并咪唑盐的合成和碳 - 碳键合反应中的催化活性

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

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)

We present herein the optimized synthesis of a triphosphenium bromide salt. Apart from being a versatile metathesis reagent, this unusually stable low-valent-phosphorus-containing compound acts as a useful P+ transfer agent. Unlike traditional methods employed to access low-coordinate phosphorus species which usually require pyrophoric phosphorus-containing precursors (white phosphorus, Tris(trimethylsilyl)phosphine, etc.), or harsh reducing agents (alkali metals, potassium graphite, etc.), the current approach does not involve pyrophoric or explosive reagents and can be done on large scales (&#62;20 g) in excellent yields by undergraduates with basic air-free synthetic training. The bromide counter ion is readily exchanged with other anions such as tetraphenyl borate (described herein) using typical salt metathesis reagents to obtain materials with desired properties and reactivities. The versatility of this P+ transfer approach is exemplified by the reactions of these triphosphenium precursors with an N-heterocyclic carbene and an anionic bisphosphine, each of which readily displace the neutral bisphosphine to give an NHC-stabilized phosphorus(I) cation and a phosphorus(I) containing zwitterion, respectively.

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI

The synthesis of a triphosphenium bromide salt is described and its use as a P+ transfer agent is outlined by reactions with an N-heterocyclic carbene and an anionic bisphosphine, yielding an NHC-stabilized P(I) cation and a P(I) containing zwitterion, respectively.

制备及反应性的Triphosphenium溴化物盐:磷方便稳定来源（I）

We present herein the optimized synthesis of a triphosphenium bromide salt. Apart from being a versatile metathesis reagent, this unusually stable ...

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

Herein is presented a general strategy to perform reactions under mild to moderate CO2 pressures with dry ice. This technique obviates the need for specialized equipment to achieve modest pressures, and can even be used to achieve higher pressures in more specialized equipment and sturdier reaction vessels. At the end of the reaction, the vials can be easily depressurized by opening at room temperature. In the present example CO2 serves as both a putative directing group as well as a way to passivate amine substrates, thereby preventing oxidation during the organometallic reaction. In addition to being easily added, the directing group is also removed under vacuum, obviating the need for extensive purification to remove the directing group. This strategy allows the facile &#947;-C(sp3)-H arylation of aliphatic amines and has the potential to be applied to a variety of other amine-based reactions.

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

Here we present a protocol for performing reactions in simple reaction vessels under low-to-moderate pressures of CO2. The reactions can be performed in a variety of vessels simply by administering the carbon dioxide in the form of dry ice, without the need for costly or elaborate equipment or set-ups.

用干冰作为固体 CO2源实现密封容器中的适度压力

Herein is presented a general strategy to perform reactions under mild to moderate CO2 pressures with dry ice. This technique obviates the need for ...

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals

Protocols for the isolation of the commonly employed cyclic (alkyl)(amino) carbene (CAAC) and N-heterocyclic carbene (NHC) are reported. Furthermore, the synthesis of their mixed CAAC&#8211;NHC &#8220;Wanzlick&#8221; dimer and the synthesis of the related stable organic &#8220;olefin&#8221; radical are presented. The main goal of this manuscript is to give a detailed and general protocol for the synthetic chemist of any skill level on how to prepare free heterocyclic carbenes by deprotonation using filter cannulas. Due to the air-sensitivity of the synthesized compounds, all experiments are performed under inert atmosphere using either Schlenk technique or a dinitrogen filled glovebox. Controlling Wanzlick&#8217;s equilibrium (i.e., the dimerization of free carbenes), is a crucial requirement for the application of free carbenes in coordination chemistry or organic synthesis. Thus, we elaborate on the specific electronic and steric requirements favoring the formation of dimers, heterodimers, or monomers. We will show how proton catalysis allows for the formation of dimers, and how the electronic structure of carbenes and their dimers affects the reactivity with either moisture or air. The structural identity of the reported compounds is discussed based on their NMR spectra.

We present protocols for the isolation of stable heterocyclic carbenes. The synthesis of a cyclic (alkyl)(amino) carbene (CAAC) and an N-heterocyclic carbene (NHC) is demonstrated using filter cannulas and Schlenk technique. We furthermore present the synthesis of the related oxygen-sensitive, electron-rich mixed &#8220;Wanzlick dimer&#8221; and the reduced stable organic radical.

分离游离卡本内斯、其混合二聚体和有机自由基

Protocols for the isolation of the commonly employed cyclic (alkyl)(amino) carbene (CAAC) and N-heterocyclic carbene (NHC) are reported. Furthermore, the ...

[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Our group recently reported the use of [(DPEPhos)(bcp)Cu]PF6 as a general copper-based photoredox catalyst which proved efficient to promote the activation of a broad variety of organic halides, including unactivated ones. These can then participate in various radical transformations such as reduction and cyclization reactions, as well as in the direct arylation of several (hetero)arenes. These transformations provide a straightforward access to a range of small molecules of interest in synthetic chemistry, as well as to biologically active natural products. Altogether, [(DPEPhos)(bcp)Cu]PF6 acts as a convenient photoredox catalyst which appears to be an attractive, cheap and complementary alternative to the state-of-the-art iridium- and ruthenium-based photoredox catalysts. Here, we report a detailed protocol for the synthesis of [(DPEPhos)(bcp)Cu]PF6, as well as NMR and spectroscopic characterizations, and we illustrate its use in synthetic chemistry for the direct arylation of (hetero)arenes and radical cyclization of organic halides. In particular, the direct arylation of N-methylpyrrole with 4-iodobenzonitrile to afford&#160;4-(1-methyl-1H-pyrrol-2-yl)benzonitrile and the radical cyclization of N-benzoyl-N-[(2-iodoquinolin-3-yl)methyl]cyanamide to afford natural product luotonin A are detailed. The scope and limitations of this copper-based photoredox catalyst are also briefly discussed.

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Detailed and general protocols are presented for the synthesis of [(DPEPhos)(bcp)Cu]PF6, a general copper-based photoredox catalyst, and for its use in synthetic chemistry for the direct arylation of C-H bonds in (hetero)arenes and radical cyclization of organic halides.

[(Dpepphos) (bcp) Cu]PF6: 一种通用的、广泛适用的铜基光氧催化剂

Our group recently reported the use of [(DPEPhos)(bcp)Cu]PF6 as a general copper-based photoredox catalyst which proved efficient to promote the ...

Introduction to Catalysis

Source: Laboratory of Dr. Ryan Richards &#8212; Colorado School of Mines
Catalysis is among the most important fields of modern technology and presently accounts for approximately 35% of the gross domestic product (GDP) and sustenance of approximately 33% of the global population through fertilizers produced via the Haber process.1 Catalysts are systems that facilitate chemical reactions by lowering the activation energy and influencing the selectivity. Catalysis will be a central technology in addressing the energy and environmental challenges of modern times.

Catalysis: Homogeneous and Heterogeneous Catalysts

催化导论

Source: Laboratory of Dr. Ryan Richards &#8212; Colorado School of Mines
Catalysis is among the most important fields of modern technology and presently ...

教育

JoVE Science Education

有机化学

Aldehydes and Ketones to Alkenes: Wittig Reaction Overview

The Wittig reaction is the conversion of carbonyl compounds&#8212;aldehydes and ketones&#8212;to alkenes using phosphorus ylides, or the Wittig reagent. The reaction was pioneered by Prof. Georg Wittig, for which he was awarded the Nobel Prize in Chemistry.
<img alt="Figure1" src="/files/ftp_upload/12335/12335_PT_Figure_1.svg" style="text-align: center; height: 75px;" />
Phosphorus ylide is a neutral molecule containing a negatively charged carbon directly bonded to a positively charged phosphorus atom. The molecule is stabilized by resonance.
<img alt="Figure2" src="/files/ftp_upload/12335/12335_PT_Figure_2.svg" style="text-align: center; height: 75px;" />
The Wittig reagents are synthesized from unhindered alkyl halides in two steps. At first, the alkyl halide undergoes an SN2 attack by a triphenylphosphine molecule generating a phosphonium salt. Next, in the presence of a strong base such as butyllithium, sodium hydride, or sodium amide, the salt undergoes deprotonation of the weakly acidic &#945; hydrogen, producing the carbanionic ylide nucleophile.
<img alt="Figure3" src="/files/ftp_upload/12335/12335_PT_Figure_3.svg" style="text-align: center; height: 75px;" />
Wittig reactions are regioselective, as the new C&#65309;C bond is formed explicitly at the carbonyl position. The stereoselectivity depends on the nature of the phosphorus ylide. Ylides with electron-withdrawing groups, such as carbonyl or aromatic rings that are stabilized by additional resonance structure, predominantly generate E alkenes. Alternatively, Wittig reagents with simple alkyl groups primarily form Z alkenes.
<img alt="Figure4" src="/files/ftp_upload/12335/12335_PT_Figure_4.svg" style="text-align: center; height: 200px;" />
The yield of Wittig reactions is influenced by steric crowding around the carbonyl group. Ketones that are sterically more hindered give poor yields compared to aldehydes. A variation of the Wittig reaction is the Horner&ndash;Wadsworth&ndash;Emmons reaction that involves a phosphonate ester reagent producing the E alkene as the major product.
<img alt="Figure5" src="/files/ftp_upload/12335/12335_PT_Figure_5.svg" style="text-align: center; height: 90px;" />

醛和酮制烯烃:Wittig 反应概述

The Wittig reaction is the conversion of carbonyl compounds&#8212;aldehydes and ketones&#8212;to alkenes using phosphorus ylides, or the Wittig reagent. ...

羰基饰卡宾的白色磷的活化制备方法和用途

摘要

探索更多视频

此视频中的章节

Mizoroki-哎呀交叉偶联反应由二氯{双[1,1'，1'' - （phosphinetriyl）tripiperidine]}钯催化在温和的反应条件