A selective synthesis of enamines versus aziridines

摘要

The reaction of 10-azidoacetyl-10H-phenothiazine with olefinic dipolarophiles depends on the reaction temperature. In refluxing toluene, a mixture of enamine and aziridine is formed in 3:1 ratio. The reaction mechanism appears to involve a Michael-type addition of the nucleophilic N1 azide atom to the olefinic double bond. In chloroform, a cycloaddition reaction takes place with the formation of a 4,5-dihydro-1,2,3-triazole. The heating of dihydrotriazoles in toluene is accompanied by nitrogen elimination leading to a mixture of enamine and aziridine in 1:3 ratio.