Synthesis of amino carbonil compounds by three-component Mannich type reaction using hafnium chloride catalyst

ß-Amino carbonyl compounds (Mannich base) and derivatives, which are easily formed from Mannich reaction, are very important compounds that are the key step in the synthesis of nitrogen-containing numerous pharmaceuticals and natural products (alkaloid). Synthetic importance of these compounds and the interest in Mannich reaction had been constantly increasing. More selective and greener methods are tested with newly developed catalysts and lots of derivated compounds were synthesized. In this study, a new method was improved using three component one-pot Mannich reaction by using Hafnium (IV) chloride catalyst for the synthesis of ß-amino carbonyl compounds. First of all, mol percent of catalyst was changed and the amount of catalyst for the best reaction yield was determined. Also, different solvents were examined for the reaction and the amount of the most appropriate solvent was determined. For the diastereoselectivity in the product, different ketone derivatives were tried. In the synthesis made with 4-tert-butyl cyclohexanone, only syn product was successfully obtained. The final solid products were crystallized in appropriate solvents, and the structures of the products were verified by 1H NMR spectrums.