The mechanism of the reaction of N β dydroxyethylethylenediamine (HEDA) on copper under catalysis for the synthesis of piperazine was studied.The structures of reaction mixtures were identified by GC MS.The preliminary study demonstrats that the above reaction is an intermolecular catalytic amination of alcohol and was proved to proceed through dehydrogenation and hydrogenation.Under the reaction conditions HEDA may undertake the bimolecular disproportionation reaction.Furthermore,the similar nucleophilic substitution reactions between starting material and products,between products and products,possibly occur to give the corresponding byproducts.
Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN generated the corresponding acyl radicals, which were found to proceed in 5 exo trig or 6 endo trig cyclisations to afford high yields of cyclopentanones and cyclohexanones, The substitution groups on the substrates have played an important role on the regioselectivity of cyclisations.
