Pd(II)-catalyzed aerobic intermolecular 1,4-diamination of conjugated dienes: A regioselective [4+4] annulation for the construction of medium-ring 1,6-benzocliazocine derivatives

The first metal-catalyzed oxidative intermolecular 1,4-diamination of conjugated dienes has been developed. A series of medium ring compounds were constructed via palladium-catalyzed intermolecular [4 +4] annulations. Oxygen was successfully used as an oxidant instead of the existing stoichiometric metals or hypervalent iodine reagents. 20 examples are reported, and good yields and regioselectivities could be obtained for the majority of diamines and conjugated diene substrates. (C) 2017 Elsevier Ltd. All rights reserved.