Synthesis of difluoromethylenephosphonated oxindoles through visible-vight-induced radical cyclization of N-arylacrylamides

摘要

A general and efficient method for the synthesis of oxindole derivatives through visible-light-induced difluoromethylenephosphonation of N-arylacrylamides has been developed. The phosphonodifluoromethyl radicals, which is generated in situ from the corresponding BrCF2PO(OEt)(2) under visible-light irradiation, in combination with N-arylacrylamides furnished difluoromethylenephosphonated oxindoles via a proposed tandem radical cyclization process. Notable advantages of this method include its simplicity and mild conditions, avoidance of toxic reagents, and compatibility with a variety of functional groups. (C) 2016 Elsevier B.V. All rights reserved.