N-BH3 ADDUCTS OF TRIALKYL-1,3,5-TRIAZACYCLOHEXANES WITH STABLE STEREOGENIC NITROGEN-ATOMS, STEREOCHEMICAL STUDY

The Syntheses and stereochemical studies of N-BH3 adducts of trialkyl 1.3,5-triazacyclohexanes [1, R = CH3; 2. R = iso-C3H7: 3. R = CH(CH3)( C6H5) (R): 4. R = tert-C4H9] are reported. Different reagent ratios we re used in order to obtain mono- and di-N-borane adducts. Tri-N-borane adducts were never observed: di-N-borane adducts were formed with tri azine 1 and 2 whereas 3 and 4 afforded only the mono-boranes. It appea rs that low steric strain is an important factor in the synthesis of t hese compounds. Borane addition produced in all cases ring and nitroge n conformationally stable compounds which were studied by NMR. All the reactions were 100% stereoselective affording one isomer in each reac tion.