RING-OPENING OF 5-MEMBERED HETEROAROMATIC AZIDES AND NITRENES

This review article gives an account of the ring-opening of five-membered heteroaromatic azides and nitrenes. It is concluded that this reaction is quite general, leading to ring cleavage and in many cases subsequent ring-closure reactions. The following heterocyclic systems are discussed in detail: furans and benzofurans, thiophenes and benzothiophenes, pyrroles and fused pyrroles, isoxazoles, oxazoles, isothiazoles and, benzoisothiazoles, thiazoles, pyrazoles and indazoles, imidazoles and fused imidazoles, 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, 1,3,4-triazoles and 1,2,4-triazoles.