title: 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 nBu3 SnH and Ph3 SnH is also described and occurs with near titration kinetics. Although the uncatalyzed addition with nBu3 SnH gave a remarkable γ-regioselectivity irrespective of the electronic nature of the aryl moiety, addition with Ph3 SnH appears to be driven by the electronic nature of the aryl alkynes.
authors.affiliation: Department of Chemistry, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada).
authors.forename: Martins S
authors.initials: MS
authors.lastname: Oderinde
authors.forename: Robert D J
authors.initials: RD
authors.lastname: Froese
authors.forename: Michael G
authors.initials: MG
authors.lastname: Organ
keywords: hydrostannylation; radicals; regioselectivity; stereoselectivity; vinylstannane