The Wittig-type Reaction of O=C–, C=C–, and N=C–Substituted Methylenetriphenylphosphoranes with N-Sulfinyl-p-toluenesulfonamide. An Intramolecular 1,3-Dipolar Cyclization of Imidoylconjugated Thione S-Imides

Abstract

Abstract The Wittig-type reactions of N-sulfinyl-p-toluenesulfonamide with (1) O=C–, (2) C=C–, and (3) N=C-conjugated phosphorus ylides were investigated. In the reaction with (1), N-sulfinyl-p-toluenesulfonamide reacted at both the ylide and the carbonyl moiety to form TsN=C-conjugated thione S-imide, which underwent intramolecular 1,3-dipolar cycloaddition of the CSN group with the aromatic C=C bond of the tosyl group giving a structurally unique spiro-fused tricyclic adduct. The structure of the adduct was determined by means of X-ray diffraction. In the reactions with (2) and (3), 1-azadiene and sulfobetaines were obtained instead of the expected conjugated thione S-imides.