Chelate-controlled carbonyl addition reactions. The exceptional chelating abilityof dimethylaluminum chloride and methylaluminum dichloride
作者:David A. Evans、Brett D. Allison、Michael G. Yang
DOI:10.1016/s0040-4039(99)00739-x
日期:1999.6
Highly selective chelatinn-controlled aldol and allyl nucleophile additions to β-alkoxy aldehydes promoted by dimethylaluminum chloride and methylaluminum dichloride are described. Cationic aluminum chelates are proposed as intermediates in these reactions. Evidence is provided to support the claim that chelate organization with Me2AlCl and MeAlCl2 is possible even with β-tert-butyldimethyl-silyloxy
描述了由氯化二甲基铝和二氯化甲基铝促进的对β-烷氧基醛的高度选择性的螯合蛋白控制的羟醛和烯丙基亲核试剂加成。阳离子铝螯合物被提议作为这些反应的中间体。提供了证据支持即使具有β-叔丁基二甲基-甲硅烷氧基也可以与Me 2 AlCl和MeAlCl 2螯合的说法。提供了立体选择性数据,该数据比较了Me 2 AlCl,McAlCl 2,SnCl 4和TiCl 4的螯合电位。