Abstract Thermolysis of 6-aryl-1, 5-diazabicyclo [3.1. 0] hexanes in the presence of 1, 3- dipolarophiles having an unsymmetrically substituted double C= C bond (such as N- arylimides derived from 2-aryl-substituted maleic, citraconic, and itaconic acids, ethyl propynoate, aryl isocyanates, and aryl isothiocyanates) leads to formation of the corresponding 1, 3-dipolar cycloaddition products. The reaction is regioselective, and in ...