Synthesis of optically active allyltin compounds and their application to enantioselective synthesis of secondary homoallyl alcohols

Article abstract of DOI:10.1021/om00126a014

Three types of optically active allyltin compounds, R*₂Sn(allyl)₂ (R* = 2-phenylbutyl, 2-methylbutyl, and 3-phenylbutyl), R*R¹Sn(allyl)₂ (R* = 2-octyl or 2-phenylbutyl, R¹ = phenyl), and R*R¹R²Sn(allyl) (R* = 2-phenylbutyl, R¹ = phenyl, R² = methyl), have been synthesized. On the basis of ¹H NMR spectra, a π-stacking interaction between the 2-phenylbutyl and the allyl groups is suggested. Optically active allyltin compounds thus obtained were subjected to reaction with aldehydes. Among various allyltin compounds, only diallylbis(2-phenylbutyl)tin exhibits good enantioselectivity. The reaction proceeds through addition of the allyl group on the re face of aldehydes. The mechanism can be accounted for on the basis of a π-stacking interaction between allyl and phenyl groups.