Density Functional Study of Platinum(II)-Mediated Bicyclization of 1,6-Dienylphenols

Abstract

Density functional studies of the cyclization of a 1,6-dienylphenol by a Pt(II)-pincer complex were performed to better understand the mechanism of the bicyclization reaction. Of the four different diastereomers of the reaction's final product, the isomer resulting from the chairlike transition state that places the activated alkene in a pseudo-equatorial orientation was found to be the most stable, in agreement with experimental observations. The study of reaction mechanism concludes that the bicyclization proceeds in the presence of base via a concerted path with no significant barrier, while the stepwise path involving a discrete carbocationic intermediate seems less favorable.