A general strategy for the synthesis of difluoromethyl-containing pyrazoles, pyridines and pyrimidines

Difluoromethyl-containing heteroannulated pyridines, pyrimidines and pyrazoles are prepared by a two step method. The regioselective cyclizations of electron-excessive aminoheterocycles, hydrazines and amidines with CF2Cl-substituted 1,3-dicarbonyl compounds provide the corresponding CF2Cl-substituted heterocycles. Subsequent radical reactions with trimethylstannane or allyltrimethylstannane gave difluoromethyl-containing heteroannulated pyridines, pyrimidines and pyrazoles, respectively.