On the hydrostannylation of aryl propargylic alcohols and their derivatives: Remarkable differences in both regio- and stereoselectivity in radical- and nonradical-mediated transformations

Abstract

Herein, we describe a highly regio- and stereoselective radical-mediated and molecular-oxygen (O2)-dependent hydrostannylation of phenyl propargylic alcohols and their derivatives. There is a significant steric effect on the stereoselectivity of the tin-radical addition. Further, the uncatalyzed regio- and stereoselective hydrostannylation of aryl propargylic alcohols with nBu3SnH and Ph3SnH is also described and occurs with near titration kinetics. Although the uncatalyzed addition with nBu3SnH gave a remarkable γ-regioselectivity irrespective of the electronic nature of the aryl moiety, addition with Ph3SnH appears to be driven by the electronic nature of the aryl alkynes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.