The attempted stereoselective synthesis of chiral 2,2′-biindoline
摘要:
The attempted first stereoselective synthesis of 2,2'-biindoline using a metathesis-Sharpless asymmetric dihydroxylation strategy results in the synthesis of the heterocycle in poor to modest stereoselectivity. Attempts to improve the ee by varying the heteroatom protecting groups in key intermediates did not enhance the outcome of the Sharpless AD reaction. Therefore a limitation of this AD reaction is the use of 1,4-substituted but-2-enes where these substituents are ortho-substituted aromatics. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.
作者:William E. Crowe、Daniel R. Goldberg、Zhijia J. Zhang
DOI:10.1016/0040-4039(96)00230-4
日期:1996.3
Allylsilanes are prepared by simple metathetical cross-coupling of terminal olefins with allyltrimethylsilane. Allytrimethylsilane coupling with π-substituted terminal olefins (styrenes, 1-phenyl-1,3-butadiene, and acrylonitrile) proceeds in excellent yield and very high selectivity. Lower, but still useful, selectivities are observed for allyltrimethylsilane/alkyl olefin cross-metathesis reactions
Nozaki–Hiyama–Kishi reaction has been widely applied in the functionalization of carbonyl compounds with the help of Ni catalysis. Herein, a divergent regio- and stereoselective diarylation of dienes has been developed under Ni/Cr cocatalysis without the inherent driving force for the formation of polar metalalkoxides. Preliminary experimental studies have been conducted to elucidate the key roles of Ni, Cr