Controlling the α/γ-Reactivity of Vinylogous Ketone Enolates in Organocatalytic Enantioselective Michael Reactions
作者:Igor Iriarte、Olatz Olaizola、Silvia Vera、Iñaki Gamboa、Mikel Oiarbide、Claudio Palomo
DOI:10.1002/anie.201703764
日期:2017.7.17
The first regio-, diastereo-, and enantioselective direct Michael reaction of β,γ-unsaturated ketones with nitroolefins is enabled by Brønsted base/hydrogen-bonding bifunctional catalysis. A squaramide-substituted tertiary amine catalyzes the reaction of a broad range of β,γ-unsaturated ketones to proceed at the α-site exclusively, giving rise to adducts with two consecutive tertiary carbon stereocenters
布朗斯台德碱/氢键双功能催化能够实现β,γ-不饱和酮与硝基烯烃的第一个区域,非对映和对映选择性直接Michael反应。方胺取代的叔胺催化广泛的β,γ-不饱和酮反应仅在α位进行,从而产生了两个连续的叔碳立体中心的非对映异构体比率最高> 20:1的加合物,并且对映选择性通常在90–98%ee范围内。