Iminyl radicals: Part I. generation and intramolecular capture by an olefin.

Slow addition of tributylstannane to sulphenylimines 2 give the corresponding Δ1- pyrrolenines 5 by an intramolecular addition of the intermediate iminyl radical, a process which can be easily coupled to an intermolecular addition to an electrophilic olefin.