Synthesis of Difluoroalkylated Heteroarenes via Difluorocarbene.

A diversity-oriented and C2-selective synthesis of difluoroalkyl-substituted heteroarenes from three fragments, N-methoxyazinium salts, difluorocarbene, and electrophilic or radical reagents, is described. The reaction proceeds via the addition of difluorinated phosphorus ylide to in situ methylated heteroarene N-oxides, leading to phosphonium salts, which can undergo further transformations under basic or photoinduced conditions.