Rhodium-Catalyzed Asymmetric Tandem Cyclization for Efficient and Rapid Access to Underexplored Heterocyclic Tertiary Allylic Alcohols Containing a Tetrasubstituted Olefin

The first Rh-catalyzed asymmetric tandem cyclization of nitrogen- or oxygen-bridged 5-alkynones with arylboronic acids was achieved. The simple catalytic system involving a rhodium­(I) complex with readily available chiral BINAP ligand promotes the reaction to proceed in a highly stereocontrolled manner. This protocol provides a very reliable and practical access to a variety of chiral heterocyclic tertiary allylic alcohols possessing a tetrasubstituted carbon stereocenter and an all-carbon tetrasubstituted olefin functionality in good yields with great enantioselectivities up to 99% ee.