UV ABSORPTION SPECTRA AND REACTION PATHWAYS FOR SULFONYL- DIHYDROPYRIDINE AND FUSED DERIVATIVES THROUGH (TD)DFT CALCULATIONS.

MARIA VICTORIA COOKE; GUADALUPE FIRPO; WALTER J. PELÁEZ; GUSTAVO A. ARGÜELLO

Bogotá

Exposici�n; PREFALC (Programme Régional France - Amerique Latine Caraíbe); 2015

INTRODUCTION Dihydropyridine derivatives are widely known as gifted starting materials for the synthesis of di- and tetrahydropyridines, which have been used asintermediates in alkaloid synthesis,1 and as important biologically active structures.2 It is known that one key aspect about the reactivity of pyridine and its derivatives isthat once activated, they can react with a large variety of nucleophiles to afford substituted dihydropyridines, which can further be reactivated to undergo secondarynucleophilic additions.3 Also, 1,2,3,4-tetrahydroquinoline and benzenesulfonyl derivatives are structures with well known biological activities.4OBJECTIVES Study the UV spectra of sulfonyl-dihydropyridine and fused derivatives and to determine the mechanism pathways that they follow in a thermal reaction.CONCLUSIONSA conformational analysis of compounds 3-6 shows that the main contribution to the total UV spectrum comes from the -in conformer. For compound 4 the HOMOLUMOtransition appears to be optically inactive.From this study we can propose that the trifluoromethylsulfonyl moiety is the most susceptible part to suffer a thermal reaction in Compounds 1 and 2 . Analysis ofpossible dissociations, allow us to conclude that the N-SO2 bond appears to be more weak than the SO2-CF3 for both compounds. After these processes occur, the mainproducts of the thermic reactions are obtained, as was demonstrated for compound 1.