Synthesis of Chiral Cleft C,N-Palladium and Iridium Complexes from 2,3:6,7-Dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-dione and Their Synthetic Applications

A transition-metal-mediated functionalization of 2,3:6,7-dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-dione is reported. By the use of the corresponding imine, iridium or palladium complexes were prepared, and they were well characterized by NMR and single-crystal X-ray crystallographic analysis. The catalytic activity of these two metal complexes was briefly investigated in hydrogenation and 1,2-addition reactions. Finally, the catalytic bromination of 2,3:6,7-dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-dione was realized in the presence of NBS and Pd(OAc)2. Subsequently a new class of V-shaped molecules with biphenanthridine skeletons were synthesized.