Kinetic versus thermodynamic stereoselectivity in the hydrostannylation of propargylic alcohol derivatives using AIBN and Et3B as promotors.
Et(3)B versus AIBN: Equally radical? The stereoselectivity of hydrostannylation of internal propargyl alcohol derivatives has been studied by using both 2-2'-azobisisobutyronitrile (AIBN) and Et(3)B as promoters. With silyl-protected alcohols, complete Z selectivity of the resultant vinylstannane has been achieved with Et(3)B, whereas AIBN shows zero stereoselectivity. Evidence suggests that, despite decades of acceptance, the hydrostannylation mechanisms employing Et(3)B and AIBN appear to be mechanistically distinct.
Department of Chemistry, York University, Toronto, ON, Canada.
Martins S
MS
Oderinde
Howard N
HN
Hunter
Michael G
MG
Organ