The reaction of amino ketones with titanium tetrachloride/zinc powder has been studied in tetrahydrofuran and 1,4-dioxane under an argon atmosphere. Symmetrical 1,8-diaminoalkenes 2 were obtained from the corresponding Mannich base hydrochlorides 1 via the intermolecular reductive coupling, and azacycloalkenes 4 were prepared from diketoamines 3 via the intramolecular reductive coupling under similar conditions.