Visible-light palladium catalysis for alkylated and difluoroalkylated pyrazolones

Abstract

We report a photoinduced palladium-catalyzed protocol for the synthesis of biologically relevant alkylated and difluoroalkylated pyrazolones via a radical cascade between N'-arylidene-N-acryloylphenylhydrazides and unactivated alkyl and difluoroalkyl halides. The protocol exhibits broad substrate scope, good functional group tolerance, and applicability to complex drug and natural product-derived fragments.