A general decarboxylative borylation protocol of aliphatic and aromatic carboxylic acids has been developed. Both stabilized and activated aryl and alkyl radicals could be generated from the leaving‐group‐assisted N‐hydroxybenzimidoyl chloride esters, even trifluoroethyl substrates could be activated for further elaboration.
Redox‐active esters (RAEs) as active radical precursors have been extensively studied for C−B bond formations. However, the analogous transformations of stabilized radicals from the corresponding acid precursors remain challenging owing to the strong preference towards single‐electron oxidation to the stable carbocations. This work describes a general strategy for rapid access to various aliphatic and aromatic boronic esters by mild photoinduced decarboxylative borylation. Both aryl and alkyl radicals could be generated from the leaving group‐assisted N‐hydroxybenzimidoyl chloride esters, even α‐CF3 substituted substrates could be activated for further elaboration.
Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Qiang Zhang, Xiaojuan Li, Weigang Zhang, Shengyang Ni, Yi Wang, Yi Pan