N-Heterocyclic Carbene Catalyzed Oxidative Coupling of Alkenes/ α-Bromoacetophenones with Aldehydes: A Facile Entry to α,β-Epoxy Ketones
作者:Rambabu N. Reddi、Pragati K. Prasad、Arumugam Sudalai
DOI:10.1002/anie.201507363
日期:2015.11.16
A novel, N‐heterocyclic carbene (NHC) catalyzed direct oxidative coupling of styrenes with aldehydes has been described for the synthesis of α,β‐epoxy ketones in good yields. This unprecedented regioselective oxidative coupling employs NBS/DBU/DMSO (DBU=1,8‐diazabicyclo [5.4. 0] undec‐7‐ene, DMSO=dimethylsulfoxide, NBS=N‐bromosuccinimide) as an oxidative system at ambient conditions. Additionally,
已描述了一种新颖的N-杂环卡宾(NHC)催化的苯乙烯与醛直接氧化偶联反应,可高产率地合成α,β-环氧酮。这种史无前例的区域选择性氧化偶合在环境条件下采用NBS / DBU / DMSO(DBU = 1,8-二氮杂双环[5.4。0]十一碳烯-7,DMSO =二甲基亚砜,NBS = N-溴代琥珀酰亚胺)作为氧化体系。此外,还描述了在温和的反应条件下,第一个由NHC催化的α-溴代酮和醛类的Darzens反应。有趣的是,机理研究表明,NHC与烯烃/α-溴代酮而不是醛具有更好的反应性,因此可通过酮脱氧Breslow中间体进行反应。