The Regioselective Switch for Amino-NHC Mediated C–H Activation of Benzimidazole via Ni–Al Synergistic Catalysis
摘要:
We have disclosed a new mode of a chemically regioselective switch for C-H bond functionalization of benzimidazole derivatives via a cooperative effect invoked by Ni-Al bimetallic catalysis to create a steric requirement for obtaining the linear product of styrene insertion. Yet, excluding the AlMe3 cocatalyst switches the reaction toward branch selectivity.
Mechanistic Study of a Switch in the Regioselectivity of Hydroheteroarylation of Styrene Catalyzed by Bimetallic Ni-Al through CH Activation
作者:Wen-Ching Chen、Ying-Chieh Lai、Wei-Chun Shih、Ming-Shiuan Yu、Glenn P. A. Yap、Tiow-Gan Ong
DOI:10.1002/chem.201400303
日期:2014.6.23
previously reported a highly efficient protocol for bimetallicNi–Al‐catalyzedhydroheteroarylation of styrene with benzimidazole based on CH bond activation. We have now delineated the mechanism of this process, providing a rationale for an observed switch in regioselectivity in the presence of the Lewis acid, AlMe3. The present mechanisticstudy gives insights for the rational development of catalysts