The Study On Primary Amine Catalytic Aldol Condensation Reaction And Kinetic Resolution Of β-Hydroxyl Ketone

The aldol condensation reaction is one of the most important methods for valuableC-C bond-forming reaction which allows β-hydroxyl aldehydes and ketones,α,β-unsaturated carbonyl compounds, trans1,2-alcohol to be obtained. Thesecondensation products are widely used in synthesis of complex natural products andbiological products. List and BarbasIII etc found proline is effective catalyst in directasymmetry aldol condensation reaction, which the amino acid of small organicmolecules Conduct as a special kind of catalyst in a creative way. So, this paper putsforward in primary amine catalytic aldol condensation reaction and study on kineticresolution of β-hydroxyl ketones.Firstly, we design and synthesize a series of glycine salt metal organic catalyst,which used in catalyzing aldol condensation reaction between cyclohexanone or acetoneand various aryl aldehydes. The results show that: aldol condensation reactions ofaromatic aldehydes and ketones on water at room temperature have been developed andthe best catalytic efficiency is observed with ld potassium glycinate. when the water issolvent, the use of the20mol%of the catalyst can get corresponding condensationproduct α,β-unsaturated ketone with69%yield. By simple separation of the oil phase,potassium glycinate-containing water was reused to catalyze aldol condensation for sixruns without loss of catalytic activity. Higher temperature can conducive to shorten thereaction time and improve the yield of condensation reaction. The kinetic resolution ofcondensation products β-hydroxyl ketones can get satisfactory higher yield and ee value,only when the chiral amino acids are phenylalanine and proline in solvent NMP.Secondly, base on the transition state theory and enamine mechanism, In this thesisthe theoretical research on the mechanism of the glycinate catalyst aldol condensationreaction and transition state theory is carried out by the theory method at B3LYP/6-31G*level. By looking for transition state structure in two possible path of thetemplate reaction and calculation of activation energy, investigation revealed correlationbetween the yields and dehydroxylation energy barriers of aldol products, reasonablylow activation energy of49.8kJ/mol for transition state formation in condensation ofbenzaldehyde and acetone, and vibration between aldol donor and acceptor, whichcorresponded to the only imaginary frequency (-179.8i).