Side-Arm-Promoted Highly Enantioselective Ring-Opening Reactions and Kinetic Resolution of Donor-Acceptor Cyclopropanes with Amines

A Ni-catalyzed asymmetric ring-opening reaction of 2-substituted cyclopropane-1,1-dicarboxylates with aliphatic amines has been accomplished using the chiral indane-trisoxazoline (In-TOX) ligand. This highly enantioselective reaction provides an efficient approach to a variety of chiral gamma-substituted gamma-amino acid derivatives, which are readily transformed into multifunctionalized piperidines and gamma-lactams. The single-crystal X-ray structure of the TOX-Ni complex is provided, and the role of the side arm in the chiral ligand is discussed.