一锅区域选择性和非对映选择性的方法,从中合成5- (杂)芳酰基-7-(杂)芳基六氢苯并[4,5]戊烯[1,6 a - b ](硫代)吡咯烷嗪-6,12-二酮可开发的1,5-二(杂)芳基戊-4-烯-1,3-二酮或姜黄素的产率为38-98%。该反应按顺序进行,由茚三酮和(硫代)脯氨酸在相应的二烯二酮的C═C键上原位生成的偶氮甲嘧啶1,3-偶极环加成,随后自发的分子内羟醛缩合,导致氮杂四喹烷的形成。脚手架。
Nucleophilic acylation of α-haloketones with aldehydes: an umpolung strategy for the synthesis of 1,3-diketones
摘要:
The first example of N-heterocyclic carbene (NHC)-promoted intermolecular acylation of alpha-haloketones with aldehydes and alpha,beta-unsaturated aldehydes (enals) is reported. The protocol involves carbonyl umpolung reactivity of aldehydes and enals in which the carbonyl carbon attacks nucleophilically on electrophilic terminal of alpha-haloketones to afford 1,3-diketones and alpha,beta-unsaturated 1,3-diketones, respectively. Short reaction time, ambient temperature, operational simplicity, and high yields are the salient features of the present procedure. (C) 2010 Elsevier Ltd. All rights reserved.