Synthesis of hetero- and carbocycles by nucleophilic substitution at sp² carbon

Vinylic halides having alcohol, sulfonamide, active methine, and thiol moieties as nucleophiles cyclize to hetero- and carbocycles by intramolecular nucleophilic substitution at the sp² carbon centers. The density functional theory calculations suggest that the cyclization proceeds through S_N2-type substitution (the in-plane vinylic nucleophilic substitution, S_NVσ), when vinyl halides are substituted with oxygen, nitrogen, and carbon nucleophiles. The substitution with sulfur nucleophiles, in contrast, proceeds through both routes of S_NVσ and out-of-plane vinylic nucleophilic substitution (S_NVπ).