Carbonyl and olefin hydrosilylation mediated by an air-stable phosphorus(<scp>iii</scp>) dication under mild conditions
作者:Ryan J. Andrews、Saurabh S. Chitnis、Douglas W. Stephan
DOI:10.1039/c9cc02460c
日期:——
The readily-accessible, air-stable Lewis acid [(terpy)PPh][B(C6F5)4]21 is shown to mediate the hydrosilylation of aldehydes, ketones, and olefins. The utility and mechanism of these hydrosilylations are considered.
已显示出易于获得的,空气稳定的路易斯酸[(terpy)PPh] [B(C 6 F 5)4 ] 2 1可介导醛,酮和烯烃的氢化硅烷化。考虑了这些氢甲硅烷基化的效用和机理。
Hydrosilylation of Carbonyls Catalyzed by Hydridoborenium Borate Salts: Lewis Acid Activation and Anion Mediated Pathways
multinuclear NMR measurements for catalysts 1 and 2. The combined effect of carbonyl activation via the Lewisacidic hydridoborenium cation and the hydridic nature of the borate counteranion in 1 makes it a more efficient catalyst in comparison to that of carbonyl activation via the predominant Lewisacid activation pathway operating with catalyst 2. The catalytic cycle of 1 showed hydride transfer from
Copper(I) complexes featuring N-heterocyclic carbenes (NHCs) in which the nitrogen atoms are substituted by a 9-ethyl-9-fluorenyl group (EF) have been synthesised and tested in the hydrosylilation of functionalized and/or sterically demanding ketones and aldehydes. These reactions, carried out with triethylsilane as hydride source, were best achieved with the imidazolylidene copper complex 2d in which
methyl cation bearing N,N′-chelated conjugated-bis-guanidinate (CBG) has been reported. Its use in the catalysis of the hydrosilylation of a wide array of carbonyls, alkenes, and alkynes has been investigated. In addition, its behavior in the catalysis of the chemoselective hydrosilylation of aldehydes in the presence of reducible functional groups has been examined.
BICAAC-Derived Covalent and Cationic Ir(I) Complexes: Application of Ir(BICAAC)Cl(COD) Complexes as Catalysts for Transfer Hydrogenation and Hydrosilylation Reactions
作者:Mandeep Kaur、Manu Adhikari、Krishna K. Manar、Yuvraj Yogesh、Darsana Prakash、Sanjay Singh
DOI:10.1021/acs.inorgchem.3c01914
日期:2024.1.22
(Me/iPrBICAAC) upon reaction with [IrCl(COD)]2 smoothly afford mononuclear Ir(I) complexes that have been spectroscopically and structurally characterized. These complexes exhibit good catalytic activity for transfer hydrogenation (TH) of 4-chlorobenzaldehyde using isopropyl alcohol (iPrOH), with turnover frequency values ranging between 6269 and 8093 h–1. Choosing the covalent complex Ir(MeBICAAC)Cl(COD)
两亲性双环(烷基)(氨基)卡宾( Me/iPr BICAAC)与[IrCl(COD)] 2反应后顺利生成单核Ir(I)配合物,并已对其进行了光谱和结构表征。这些配合物对使用异丙醇 (iPrOH) 的 4-氯苯甲醛转移氢化 (TH) 表现出良好的催化活性,周转频率值范围在 6269 至 8093 h –1之间。选择共价配合物 Ir( Me BICAAC)Cl(COD) 作为催化剂,对一系列用吸电子和给电子取代基功能化的羰基和亚胺进行了研究,并以中等到良好的产率提供了还原产物。当Ir( Me BICAAC)Cl(COD)在甲苯-d 8或异丙醇-d 8中长时间加热时,没有观察到BICAAC单元从Ir中心脱离,这证明了催化剂良好的热稳定性。配合物 Ir( Me BICAAC)Cl(COD) 还被发现对使用三乙基硅烷 (Et 3 SiH) 的多种醛的氢化硅烷化具有催化活性。