An imine-gallium Lewis pair stabilized oxophosphinidene via an unexpected phosphirene rearrangement.

The reaction of a DAC-derived phosphirene 1 with AlCl3 reveals the formation of a simple donor acceptor adduct 2 of the DAC carbonyl fragments with AlCl3. In contrast, GaCl3 induces an unexpected rearrangement leading to the formation of an imine/GaCl3 stabilized 1,2-azaphosphole-based oxophosphinidene 3. This latter compound represents the first example of the R-P[double bond, length as m-dash]O fragment stabilized by a main group donor-acceptor interaction.