描述了高效的铟(III)催化的各种羧酸与1,1,3,3-四甲基二硅氧烷(TMDS)和溴或碘源的还原溴化或碘化。该官能团互变对几种官能团具有高耐受性,例如卤素,羟基,硝基,烯烃部分和硫化物部分。该铟催化体系也适用于醛化,酰氯和酯的还原碘化。此外,该还原体系可通过添加亲核试剂用于一锅法合成卤代烷和胺衍生物。通过1 H和13 C NMR监测实验的时间过程以及相应的逐步反应,可以深入了解反应机理。
Syntheses of Aldol Products and Cyanohydrins from Carboxylic Acids Using Hydrosilanes, Organosilicon Reagents, and Indium Triiodide Catalyst
作者:Yoshihiro Inamoto、Yoshihiro Nishimoto、Makoto Yasuda、Akio Baba
DOI:10.1246/cl.130790
日期:2013.12.5
Carboxylic acids were applied to an indium triiodide-catalyzed reductive aldol reaction and a reductive cyanation in order to produce aldol adducts and cyanohydrins, respectively, in which the separate addition of two kinds of hydrosilanes was crucial in combination with either ketene silyl acetals or silyl cyanides.
An Efficient Solvent-Free Route to Silyl Esters and Silyl Ethers
作者:Yuko Ojima、Kazuya Yamaguchi、Noritaka Mizuno
DOI:10.1002/adsc.200900230
日期:2009.6
Abstractmagnified imageDinuclear metal complexes, especially (p‐cymene)ruthenium dichloride dimer [RuCl2(p‐cymene)]2}, have been found to exhibit high catalytic performance for the dehydrosilylation of various kinds of carboxylic acids and alcohols. The dehydrosilylation with [RuCl2(p‐cymene)]2 proceeded efficiently with only one equivalent of silane with respect to substrate (carboxylic acids or alcohols) under solvent‐free conditions to give the corresponding silyl esters and ethers in excellent yields with a high turnover number (TON) and frequency (TOF). The 1H NMR spectrum of a toluene‐d8 solution of [RuCl2(p‐cymene)]2 and a silane showed a signal assignable to the ruthenium hydride species. In contrast, no new signals were detected in the 1H NMR spectrum of a toluene‐d8 solution of [RuCl2(p‐cymene)]2 and a carboxylic acid or an alcohol. Therefore, the ruthenium metal in [RuCl2(p‐cymene)]2 activates a silane to afford the hydride intermediate, possibly a silylmetal hydride species. Then, the nucleophilic attack of a substrate (carboxylic acid or alcohol) to the hydride intermediate proceeds to give the corresponding silylated product. The present dehydrosilylation with an optically active silane proceeded exclusively under inversion of stereochemistry at the chiral silicon center, suggesting that the nucleophilic attack of a substrate to the hydride intermediate occurs from the backside of the ruthenium‐silicon bond.