Catalytic Asymmetric Chloroamination Reaction of α,β-Unsaturated γ-Keto Esters and Chalcones

• DOI: 10.1021/ja110668c
• Publication Date: 2011-03-28T14:58:29Z
• Authors: Yunfei Cai; Xiaohua Liu; Jun Jiang; Weiliang Chen; Lili Lin; Xiaoming Feng
• Keywords: Vicinal

Highly efficient catalytic chloroamination reaction of α,β-unsaturated γ-keto esters and chalcones has been developed via a chloronium-based mechanism to deliver anti-regioselective vicinal chloroamines instead the aziridinium intermediates delivered aminochlorides. The combination TsNCl(2) TsNH(2) as reagents made transformation highly efficient, delivering γ-carbonyl-β-chloro-α-amino acid derivatives α-chloro-β-amino-ketone in nearly quantitative yields with up 99% ee 99:1 dr under 0.05-0.5 mol % catalyst loading. TsNHCl was demonstrated act key reactive species form bridged chloronium ion intermediate presence chiral scandium complex. method might provide useful information for further realization other haloamination reactions.