Study On The Synthesis Of Chiral Hetero-helicene-likes And Nitrogen Heterocyclic Compounds

Helicenes and helicene-like molecules have been regarded as academic curiositybecause they show nonplanar ortho-fused characteristics and exhibit the feature of helicalchirality. With the recent advances in this research area, helicenes and helicene-likemolecules are considered to be potential candidates serving as liquid crystal molecules,sensors, and dyes. They can also be applied in areas of asymmetric catalysis, chiralmolecular recognition, and molecular machinery. Helicene chemistry has grown from thestage of a descriptive field of aesthetic and curious molecules to an important field ofresearch.This dissertation consisted of two parts. The first one is focused on the synthesis andapplication of chiral hetero-helicene-likes. The second one is the synthesis of heterocycliccompounds.The first section,2-hydroxybenzaldehydes and diamines were utilized as the startingmaterials, the formed diimines then undergo a reductive-cyclization process withtriphosgene to give the dioxo-diaza-helicene skeleton induced by low-valent titaniumreagent. Then through the conversion of functional groups, the dioxo-diaza-helicene-likecompounds containing hydroxy group have been obtained in83-89%yields by from theircorresponding compounds containing methoxy group in the presence of BBr3.The second section, chiral diphenyl diamine, substituted salicylaldehyde or2-hydroxy naphthalene aldehyde derivative were used as the starting material, the formeddiimines then undergo a reductive-cyclization process with triphosgene a step, easily togive the chiral dioxo-diaza-helicene-likes, the enantioselectivity of the product was up to99.9%ee. The structures of the products have been determined by the X-raycrystallographic analysis. The desired chiral dioxo-diaza-helicene-like compoundscontaining hydroxy group were obtained in85-90%yields, up to99.9%ee, in addition, the hydroxy dioxo-diaza-helicene-like compound was applications on the asymmetricnucleophilic addition of Et2Zn to aldehydes get ee values60-78%and in the yield91-98%.In third section,2-hydroxybenzaldehydes (or2-nitrobenzaldehydes) and chiralcyclohexane-1,2-diamine were utilized as the starting materials, the formed diiminespromoted by low-valent titanium reagen, an access to get benzo[5,6][1,3]oxazino[4,3-c]quinoxaline-dione or octahydroquinoxalino[1,2-c:4,3-c’]diquinazoline-dione derivatives,the enantioselectivity of the product was up to99.9%ee.In forth part, a facile microwave irradiation synthesis of the new helicene-likescompounds benzo[5,6]chromeno[4,3-d]-pyrazolo[3,4-b]pyridin-3-one derivatives bybenzo[f]chromen-3-one amino pyrazole derivatives reactived in DMF and with silicon acidas catalyst is described. While benzo[5,6]chromeno[2,3-b]-pyrazolo[4,3-e]pyridinederivatives can be constructed if the reaction conditions have been changed.