Pd-Catalyzed O-Arylation of Ethyl Acetohydroximate: Synthesis of O-Arylhydroxylamines and Substituted Benzofurans

摘要

An efficient Pd catalyst for the O-arylation of ethyl acetohydroximate with aryl chlorides, bromides, and iodides has been developed. Ethyl acetohydroximate serves as an efficient hydroxylamine equivalent for C-O cross-coupling, thereby allowing for the preparation of Oarylhydroxylamines from simple aryl halides. Short reaction times and broad substrate scope, including heteroaryl coupling partners, allow access to Oarylhydroxylamines that would be difficult to prepare in a single step by traditional methods. Moreover, the O-arylated products so formed can be directly transformed into substituted benzofurans in a single operation.