Regio-controlled pentadienylation of sulfinylimines by pentadienyltin reagent. Efficient Lewis acid activation of 4-methoxyphenylsulfinyl imines

Nucleophilic addition of pentadienyltin reagent toward N-(4-methoxyphenylsulfinyl)-imine was effectively accelerated by the use of InCl3 or TMSOTf as a Lewis acid. The former afforded the γ-adduct with high stereoselectivity, while the latter gave the ε-adduct with moderate stereoselectivity, depending on the reaction mechanisms.