Bromoporphyrins as versatile synthons for modular construction of chiral porphyrins: Cobalt-catalyzed highly enantioselective and diastereoselective cyclopropanation

A study to demonstrate that the readily accessible 5,10-bis(2',6'-dibromophenyl)porphyrins are versatile synthons for modular construction of chiral porphyrins via palladium-catalyzed multiple amidation reactions with chiral amides is presented. Findings show that Cobalt(II) complexes of the D2-symmetric chiral prophyrins are active catalysts for highly enantioselective and diastereoselective cyclo-propanation under a practical one-pot protocol.