Visible-Light Driven Selective C-N Bond Scission in -Bimane-Like Derivatives.

In the present study, we report the photochemical transformation of pyrazolo[1,2-]pyrazolone substrates that reach an excited state upon irradiation with visible light to initiate the homolytic C-N bond cleavage process that yields the corresponding N1-substituted pyrazoles. Moreover, chemoselective heterolytic C-N bond cleavage is possible in the pyrazolo[1,2-]pyrazole core in the presence of bromomalonate.