Improved dimethylzinc-promoted vinylation of nitrones with vinylboronic esters

Vinylboronic esters derived from 4,4,6-trimethyl-[1,3,2]dioxaborinane react with nitrones in the presence of dimethylzinc; nucleophilic addition of the vinyl group onto nitrones produces N-allylic hydroxylamines in fair yields. The sequence is compatible with various functional groups on the vinylic moiety. The mechanism and kinetic aspects are discussed on the basis of DFT calculations.