Reactions of aryl azides with alkenes in the presence of aluminium trichloride. Formation of novel aziridines fused to seven- and eight-membered rings

Abstract

Reactions of aryl azides (1) with cyclohexene gave 3-(arylamino)cyclohexenes (2) and trans-1-chloro-2-(arylamino)cyclohexanes (3), whereas that of (1) with cycloheptene or cis-cyclo-octene afforded novel aziridines, 8-aryl-8-azabicyclo[5.1.0]octanes(4), or 9-aryl-9- azabicyclo[6.1.0]nonanes (5), respectively. The reaction of phenyl azide (1a) with cis-4-methylpent-2-ene yielded 3-anilino-2-chloro-4-methylpentane (10), but that with the trans-alkene gave 4-anilino-2-methylpent-2-ene (7) and 3-anilino-4-methylpent-1-ene (8). The similar reaction of (1) with 3-trimethylsilylcyclohexene or 3-trimethylsilyl-cis-cyclo-octene produced only (2) or 3-(arylamino)-cis-cyclo-octenes (2′). The formation of the aziridines or the ring-opened products was explained by a mechanism via an aziridinium–AlCl₃ complex formed from an azide–AlCl₃ complex.