Novel synthesis of 4,4-difluoropyrido[4,3-b]indoles via intramolecular Heck reaction

Abstract Various difluoropyridoindoles were synthesized via a palladium-catalyzed intramolecular Heck reaction as a key step. Thus, ortho -bromoanilines and difluoropiperidinone were treated with (PPh 3 ) 2 PdCl 2 and base in pyridine to give the regioselective cyclized heterocycles in modest to satisfactory yields.