The Simultaneous In-Situ Generation of Aldehydes and Phosphorus Ylides: A Convenient Multi-Step One-Pot Olefination Protocol
作者:Qian Wang、Heng-xu Wei、Manfred Schlosser
DOI:10.1002/(sici)1099-0690(199912)1999:12<3263::aid-ejoc3263>3.0.co;2-u
日期:1999.12
nucleophilic addn. of an organolithium reagent to DMF are basic enough to deprotonate alkyltriphenylphosphonium salts suspended in THF. The aldehydes, liberated by the spontaneous decompn. of the resulting a-amino alcs. (hemi-aminals), undergo a Wittig reaction with the simultaneously generated P ylides to afford olefins in excellent overall yields. This in situ method offers the unique advantage in
Li a-(二甲氨基)醇盐由亲核加成物产生。有机锂试剂对 DMF 的碱性足以使悬浮在 THF 中的烷基三苯基鏻盐去质子化。醛,由自发分解释放。产生的α-氨基醇。(半缩醛胺),与同时生成的 P 叶立德进行 Wittig 反应,以优异的总产率提供烯烃。这种原位方法在其适用于不稳定醛方面提供了独特的优势,否则这些醛将成为 (Z/E)-异构化或自缩合过程的牺牲品。[在 SciFinder (R) 上]