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 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.