Side-arm-promoted highly enantioselective ring-opening reactions and kinetic resolution of donor-acceptor cyclopropanes with amines.

ABSTRACT

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 γ-substituted γ-amino acid derivatives, which are readily transformed into multifunctionalized piperidines and γ-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.