Platinum(II)-Catalyzed Asymmetric Ring-Opening Addition of Arylboronic Acids to Oxabenzonorbornadienes

A new
platinum­(II)-catalyzed asymmetric ring-opening addition of
arylboronic acids to oxabenzonorbornadienes was developed, which afforded
the corresponding cis-2-aryl-1,2-dihydronaphthalen-1-ol
products in high yields (up to 97%) with moderate to good enantioselectivities
(up to 89% ee) under very mild conditions. The effects of various
ligands, catalyst loading, bases, solvents, and temperatures on the
yield and enantioselectivity of the reaction were also investigated.
The cis configuration of product 2m was confirmed by
X-ray diffraction analysis. A potential mechanism for the present
catalytic reaction is proposed.