Abstract Thermal radical reactions of azidoalkynes 2, 8, 14, and 21a–c with thiols 1a–c afford 2-sulfanylvinyl radicals by selective addition of sulfanyl radicals to the triple bond. 1- Phenylvinyl radicals 23 and 30a, as well as vinyl radical 30b, undergo fast 5-cyclization onto the aromatic azide function to give cyclized indoles. In contrast, both 1-phenyl (15, 17) and 1- alkyl (3a, b, 9) vinyl radicals fail to add to their aliphatic azido substituents and exclusively ...
