Tertiary Amines as Synthetic Equivalents of Vinyl Cations: Zinc Bromide Promoted Coupling of Propargylamines with α-Isocyanoacetamides To Give 2,4,5-Trisubstituted Oxazoles Initiated by an Internal Redox Process
作者:Yann Odabachian、Qian Wang、Jieping Zhu
DOI:10.1002/chem.201302106
日期:2013.9.9
Crabée interrupted: Propargylamines 1 react with α-isocyanoacetamides 2 in the presence of zinc bromide to afford vinyl oxazoles 3. The transformation, wherein the propargylamine acts as a vinyl cation synthetic equivalent, involves a domino sequence incorporating a 1,5-hydride shift, intermolecular trapping/cyclization, and a 1,6-elimination (see scheme).
螃蟹被打断:在溴化锌存在下,炔丙胺1与α-异氰基乙酰胺2反应得到乙烯基恶唑3。该转化(其中炔丙基胺充当乙烯基阳离子合成等价物)涉及一个结合了1,5-氢化物移位的多米诺序列,分子间的捕获/环化和1,6-消除(参见方案)。