Rh/Pd Catalysis with Chiral and Achiral Ligands: Domino Synthesis of Aza-Dihydrodibenzoxepines

摘要

Domino catalysis is an ideal strategy in the synthesis of heterocyclic scaffolds, as multiple bonds can be formed under a single set of reaction conditions. Beyond the rapid generation of molecular complexity, time and cost efficiencies resulting from the lack of purification of intermediates make such methods attractive. To this end, various permutations of domino metal-, organo-, and bio-catalyzed methods have been developed, including several recent examples in which transition metals act in tandem to provide a single product. In addition, methods featuring a single metal and mixtures of chiral and achiral ligands have been described, wherein both ligands are essential to achieve good yields and selectivities owing to the formation of a ligand-metal heterocomplex.