Benzenethiol and 2-benzo[b]thiophenethiol undergo
almost instantaneous reaction with α-azidostyrene and 1-azido-trans-stilbene in benzene, at room
temperature, to give corresponding
β-sulfanylated imines and enamines in virtually quantitative yield.
With α-azidostyrene, phenethyl
and allyl mercaptan are found to react in a similar fashion, but to
rates very much lower. Results
are interpreted in terms of radical-chain reactions involving
intermediacy of 2-sulfanyliminyl
radicals which could result from sulfanyl radical attack at the azide
β-carbon followed by nitrogen
extrusion by the ensuing radical adduct.