Enantioselective Direct α-Amination of Aldehydes via a Photoredox Mechanism: A Strategy for Asymmetric Amine Fragment Coupling
作者:Giuseppe Cecere、Christian M. König、Jennifer L. Alleva、David W. C. MacMillan
DOI:10.1021/ja406181e
日期:2013.8.7
The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated N-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor
醛的直接、不对称 α-胺化是通过光氧化还原和有机催化的组合完成的。光子生成的 N 中心自由基与催化形成的手性烯胺进行对映选择性 α-加成,直接产生具有合成有用胺取代模式的稳定 α-氨基醛加合物。在胺前体上引入光不稳定基团避免了在该转化中使用光氧化还原催化剂的需要。重要的是,这种光诱导转化允许直接和对映选择性地获得不需要反应后操作的 α-氨基醛产品。
N-Heterocyclic Carbene-Catalyzed Chemoselective S–O Bond Cleavage of Benzenesulfonic Carbamate
作者:Zijun Wu、Jian Wang
DOI:10.1021/acs.orglett.8b03338
日期:2018.12.7
An unprecedented example of NHC-catalyzed chemoselective S–O bondcleavage of dinitrobenzenesulfonic carbamates is described. This protocol features several advantages, including mild reaction conditions, broad substrate scope, and operational simplicity, which allows it to be an attractive synthetic method for hydroxylamine synthesis. Notably, dinitrobenzenesulfonic carbamates not only work as “O”