Regio- and diastereoselective methoxyselenenylation of cinnamylamines attached to a chiral perhydrobenzoxazine occurs in high yields by reaction with benzeneselenenyl chloride in dichloromethane-methanol. The diastereoselection is dependent on the temperature of the reaction and the structure of the substituent at C-2 and can be rationalized by accepting a 1,4-asymmetric induction process after coordination of the selenium to the nitrogen atom of the allylamine system.