The enantioselective construction of five-membered spirocyclic oxindoles via a double Michael cascade reaction is described by using dipeptide-based multifunctional quaternary phosphonium salt catalysts. The desired products were obtained in excellent yields (up to 94%) and good to high stereoselectivities (up to >19:1 dr and 99% ee).
Alkynyl Group as Activating Group: Base-Catalyzed Diastereoselective Domino Reactions of Electron-Deficient Enynes
作者:Wenbo Li、Yuanjing Xiao、Junliang Zhang
DOI:10.1002/adsc.200900633
日期:2009.12
This paper describes a base-catalyzeddominoreaction of electron-deficientenynes with malonate-derived α,β-unsaturated esters and ketones, which provides a rapid, stereoselective access to multi-functionalized cyclopentanes and inden-5(6 H)-ones in high yields. In this reaction, the alkynylgroup of the enyne acts as an activatinggroup rather than a reacting group.