Copper-catalyzed crosscoupling of vinyl nitrenes and CF3-carbenes to synthesize CF3-2-azadienes

A unique and efficient copper catalytic system has been established to synthesize fluorinated 2-azadienes from isoxazoles and CF3-N-tosylhydrazones via crosscoupling reactions of vinyl nitrenes with CF3-carbenes. A proposed reaction pathway involves the tandem cleavage of N–O/C–N bonds and formation of a C–N double bond. The developed method features a broad substrate scope, easy handling, step economy, and well-defined regio- and stereoselectivities.