Bis(2,2,2-trifluoroethyl)bromophosphonoacetate, a Novel HWE Reagent for the Preparation of (<i>E</i>)-α-Bromoacrylates: A General and Stereoselective Method for the Synthesis of Trisubstituted Alkenes
作者:Keiko Tago、Hiroshi Kogen
DOI:10.1021/ol006074x
日期:2000.6.1
A novel reagent, methyl bis(2,2,2-trifluoroethoxy)bromophosphonoacetate (3a), was designed and prepared in order to efficiently synthesize (E)-alpha-bromoacrylates, which are useful precursors for various C-C bond formations. Honer-Wadsworth-Emmons (HWE) reaction of various aldehydes with 3a in the presence of t-BuOK and 18-C-6 gave the corresponding (E)-alpha-bromoacrylate derivatives with high stereoselectivity
设计并制备了一种新颖的试剂,双(2,2,2-三氟乙氧基)溴代膦酰基乙酸甲酯(3a),以便有效地合成(E)-α-溴代丙烯酸酯,它们是形成各种CC键的有用前体。在t-BuOK和18-C-6存在下,各种醛与3a的Honer-Wadsworth-Emmons(HWE)反应产生具有高立体选择性的相应(E)-α-溴丙烯酸酯衍生物。使用(E)-α-溴丙烯酸酯作为关键中间体,开发了通过Pd催化的交叉偶联合成三取代烯烃的一般立体选择性合成方法。