Photochemical Radical C–H Halogenation of Benzyl N‐Methyliminodiacetyl (MIDA) Boronates: Synthesis of α‐Functionalized Alkyl Boronates
Ling Yang, Dong‐Hang Tan, Wen‐Xin Fan, Xu‐Ge Liu, Jia‐Qiang Wu, Zhi‐Shu Huang, Qingjiang Li, Honggen Wang
Abstract
Abstract α‐Haloboronates are useful organic synthons that can be converted to a diverse array of α‐substituted alkyl borons. Methods to α‐haloboronates are limiting and often suffer from harsh reaction conditions. Reported herein is a photochemical radical C‐H halogenation of benzyl N ‐methyliminodiacetyl (MIDA) boronates. Fluorination, chlorination, and bromination reactions were effective by using this protocol. Upon reaction with different nucleophiles, the C−Br bond in the brominated product could be readily transformed to a series of C−C, C−O, C−N, C−S, C−P, and C−I bonds, some of which are difficult to forge with α‐halo sp 2 ‐B boronate esters. An activation effect of B(MIDA) moiety was found.