Mechanism and Scope of the Cyanide-Catalyzed Cross Silyl Benzoin Reaction
作者:Xin Linghu、Cory C. Bausch、Jeffrey S. Johnson
DOI:10.1021/ja044086y
日期:2005.2.1
the cross silyl benzoinreaction. A study of the influence of water on the KCN-catalyzed cross silyl benzoin addition revealed more practical reaction conditions using unpurified solvent under ambient conditions. A sequential silyl benzoin addition/cyanation/O-acylation reaction that resulted in two new C-C bonds was achieved in excellent yield. The mechanism of cross silyl benzoin addition is proposed
在这项工作中,描述了由金属氰化物催化的酰基硅烷 (1) 和醛 (2) 之间的交叉甲硅烷基安息香加成反应。不对称的芳基、杂芳基和烷基取代的安息香加合物可以以中等至极好的收率生成,使用氰化钾和相转移催化剂进行完全区域控制。从过渡金属氰化物配合物的筛选中,三氰化镧被确定为用于交叉甲硅烷基安息香反应的改进的第二代催化剂。水对 KCN 催化的交叉甲硅烷基安息香加成的影响的研究揭示了在环境条件下使用未纯化溶剂的更实用的反应条件。产生两个新的 CC 键的顺序甲硅烷基安息香加成/氰化/O-酰化反应以优异的产率实现。详细提出了交叉甲硅烷基安息香加成的机制,并得到了交叉研究和许多旨在确定关键步骤可逆性的明确实验的支持。更亲电子的醛组分的氰化不会产生生产性化学反应。碳-碳键的形成被证明是反应中最后的不可逆步骤。
Tandem Carbon−Carbon Bond Constructions via Catalyzed Cyanation/Brook Rearrangement/C-Acylation Reactions of Acylsilanes
作者:Xin Linghu、David A. Nicewicz、Jeffrey S. Johnson
DOI:10.1021/ol0263649
日期:2002.8.1
see text] A tandem nucleophile-catalyzed cyanation/Brookrearrangement/C-acylation has been developed. Phase transfer cocatalysts facilitate cyanide-catalyzed reactions between acylsilanes and cyanoformates to afford protected tertiary carbinol products. A catalytic cycle is proposed involving cyanation of an acylsilane, [1,2]-Brook rearrangement, and C-acylation of the derived carbanion by a cyanoformate
Acylsilanes in Iridium‐Catalyzed Directed Amidation Reactions and Formation of Heterocycles via Siloxycarbenes
作者:Peter Becker、Ramona Pirwerdjan、Carsten Bolm
DOI:10.1002/anie.201508501
日期:2015.12.14
Exposing ortho‐amido aroylsilanes to visible light or heat leads to cyclization reactions that provide N‐heterocyclic compounds via siloxycarbenes as key intermediates. The previously unreported starting materials have been prepared by directedamidations of aromatic acylsilanes in the presence of an iridium catalyst followed by N‐alkylation.
Oxidative [1,2]-Brook Rearrangements Exploiting Single-Electron Transfer: Photoredox-Catalyzed Alkylations and Arylations
作者:Yifan Deng、Qi Liu、Amos B. Smith
DOI:10.1021/jacs.7b05165
日期:2017.7.19
Oxidative [1,2]-Brook rearrangements via hypervalent silicon intermediates induced by photoredox-catalyzed single-electron transfer have been achieved, permitting the formation of reactive radical species that can engage in alkylations and arylations.
A carbamoyl anion-initiated cascade reaction with acylsilanes and imines allows rapid construction of substituted [small alpha]-hydroxy-[small beta]-amino amides in high yields with excellent diastereoselectivities.