An Articulate Oxidative Transition-Metal-Free Homocoupling of Imidazo Heterocycles through C(sp2)-C(sp2) Bond Formation

Direct oxidative homocoupling of 2-arylimidazo heterocycles was achieved by using a phenyliodine diacetate-mediated BF3OEt2-accelerated protocol at room temperature. A series of biimidazo heterocycles were synthesized under ambient conditions without prior activation of the C(sp(2))-H bond. The desired biimidazo heterocycles were also obtained by using catalytic amounts of iodobenzene and m-CPBA/AcOH in an organocatalytic fashion.