Tetraidronaftilaminas como precursoras para obtenção de tiazolidinonas e benzotiazepinonas: síntese, atropoisomerismo e elucidação estrutural

Abstract

The multicomponent one-pot by conventional heating methodology was applied to development of four series of heterocycles containing nitrogen and sulfur. They were synthetized from tetrahydronaphthalen-1-amines: 5,6,7,8-tetrahydronaphthalen-1- amine (aromatic), R-1,2,3,4-tetrahydronaphthalen-1-amine (aliphatic) and (S)- 1,2,3,4-tetrahydronaphthalen-1-amine (aliphatic). Firstly, 5,6,7,8- tetrahydronaphthalen-1-amine reacted with mercaptoacetic acid and arenealdehydes having electron-withdrawing groups gave nine 2-aryl-3-(5,6,7,8- tetrahydronaphthalen-1-yl)thiazolidin-4-one by satisfactory 47-70% yield. Also the atropisomerism phenomenom was observed in several molecules of this series. It was confirmed by variable-temperature nuclear magnetic resonance method. The energy required for the interconversion of one atropisomer into another is around 16.7 kcal.mol-1 . Chemical quantum calculation displayed that more stable isomer has the tethahidronaphthalene portion below the five-ring plane. NOESY showed that in solution the same isomer is more stable. In turn, when the same aromatic amine react with arenealdehydes bearing electron-donating groups and with two examples having electron-withdrawing groups, by p-TSOH catalysis five 5-aryl-1,5,8,9,10,11- hexahydronaphtho[1,2-e][1,4]thiazepin-2(3H)-one were obtained (56-72%). When aliphatic amines of defined stereochemistry were used as precursor were synthetized six 2-phenyl-3-R-(1,2,3,4-tetrahydronaphthalen-1-yl)thiazolidin-4-ones and six 2- phenyl-3-S-(1,2,3,4-tetrahydronaphthalen-1-yl)thiazolidin-4-ones (14-70 %), after purification some pairs of diastereoisomers were separated. The atropisomerism phenomenon was also observed in examples this kind of thiazolidinones. All compounds are unpublished and had their purities available and their structures elucidated by mass spectrometry and nuclear magnetic resonance techniques and available crystals by X-ray