Role of base in palladium-catalyzed arylation of carbanions

被引：19

作者：

Mitin, AV ^{[1
]}

Kashin, AN ^{[1
]}

Beletskaya, IP ^{[1
]}

机构：

[1] Moscow MV Lomonosov State Univ, Dept Chem, Moscow 119992, Russia

来源：

JOURNAL OF ORGANOMETALLIC CHEMISTRY | 2004年 / 689卷 / 06期

基金：

俄罗斯基础研究基金会;

关键词：

palladium; catalysis; arylation; sulfone; phosphine ligand; proton transfer;

D O I：

10.1016/j.jorganchem.2003.12.039

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The arylation reaction of carbanions, derived from certain sulfones, cyanoacetic ester and malononitrile, with aryl bromides (using the catalytic system of Pd(2)dba(3)/3L, L=PPh3, PtBu3) as well as the reaction of the carbanions with one equivalent of 4-CF3C6H4 Pd(PPh3)(2)Br has been studied. These reactions proceed smoothly provided that the base stronger than the initial carbanion is present in the reaction mixture. In the absence of the above type of base the reactions do not proceed at all. Taking that into account we have proposed a novel mechanism of palladium-catalyzed arylation of CH-acids. The main feature of this mechanism is the accelaration of the reductive elimination due to the deprotonation of the intermediate ArPdL2CHXY. The correlation between the carbanion reactivity and the pK(a) values for related CH-acids as well as the ligand effect are discussed in the framework of the proposed mechanism. (C) 2004 Elsevier B.V. All rights reserved.

引用

页码：1085 / 1090

页数：6

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