TY - JOUR A1 - Szatmari, Istvan A1 - Heydenreich, Matthias A1 - Koch, Andreas A1 - Fulop, Ferenc A1 - Kleinpeter, Erich T1 - Unexpected isomerization of new naphth[1,3]oxazino[2,3-a] isoquinolines in solution, studied by dynamic NMR and supported by theoretical DFT computations JF - Tetrahedron N2 - Through the reactions of 1-aminomethyl-2-naphthol and substituted 1-aminobenzyl-2-naphthols with 3,4-dihydroisoquinoline or 6,7-dimethoxy-3,4-dihydroisoquinoline under microwave conditions, naphth[1,2-e][1,3]oxazino[2,3-a]-isoquinoline derivatives were prepared in good yields. The latter reaction was extended by using 2-aminoarylmethyl-1-naphthols, leading to isomeric naphth-[2,1-e][1,3]oxazino[2,3-a] isoquinolines. Beside the detailed NMR spectroscopic and theoretical study of both stereochemistry and dynamic behaviour of these new conformational flexible heterocyclic ring systems an unexpected dynamic process between two diastereomers was observed in solution, studied by variable temperature H-1 NMR spectroscopy and the mechanism proved by theoretical DFT computations. KW - 3,4-Dihydroisoquinoline KW - Aminonaphthol KW - Dynamic NMR spectroscopy KW - DFT calculations KW - Conformational analysis Y1 - 2013 U6 - https://doi.org/10.1016/j.tet.2013.06.094 SN - 0040-4020 VL - 69 IS - 35 SP - 7455 EP - 7465 PB - Elsevier CY - Oxford ER -