A Highly Regio- and Stereoselective Syntheses of α-Halo Enamides, Vinyl Thioethers, and Vinyl Ethers with Aqueous Hydrogen Halide in Two-Phase Systems

A metal-free regio- and stereoselective method is achieved for the preparation of (E)-configured alpha-halo enamides, vinyl thioethers, and vinyl ethers using aqueous HX (X = F, Cl, Br, I), which features high functional group compatibility and regio- and stereoselectivity, mild conditions, high efficiency, and rapid transformation. Additionally, the isomers could be yielded readily from the (E)-configured a halo enamides via photocatalysis or under Sonogashira coupling conditions.

一种无金属的区域选择性和立体选择性方法被用于制备（E）-构型的α-卤代烯酰胺、乙烯基硫醚和乙烯基醚，该方法使用氢卤酸水溶液（X = F、Cl、Br、I），具有高的官能团兼容性以及区域选择性和立体选择性、条件温和、效率高和转化迅速的特点。此外，通过光催化或在Sonogashira偶联条件下，（E）-构型的α-卤代烯酰胺可容易地生成异构体。