Construction Of Benzo-Heterocycles Asymmetric[3+2] Cyclizations

It has been discovered that benzo-heterocyclic compounds have play an important role in medicinal and industry, because of their wide range of physiological and pharmacological activities. However, It is one of the important synthetic methods to synthesize five-membered heterocyclic compounds by [3+2] cyclization reaction.This dissertation was composed of three parts which was to synthesis of chirality benzo-heterocyclic compounds two-component with [3+2] cyclization reaction. The first part of this paper focuses on the sutdies of Chiral1,2-Dihydronaphthofurans by organocatalytic domino reactions catalyzed with multiple catalysis, the second part was about synthesis of sprio[thiophane-3-ol] derivatives by asymmetric [3+2] cyclizations, and the third part was about organocatalytic of domino [3+2] cyclization reaction to synthesis multi-functionalized3-3’-spirooxindol pyrrolopyran compounds.In the current work, double functional cinchona alkaloid was used in asymmetric tandem reactions with concerted catalysis between a-bromonitroalkene and β-naphthol. The reaction was first underwent the reaction of Michael-Friedel-Crafts alkylation, and then following the intramolecular cyclization of the phenolic hydroxyl group on the naphthalene. Under the optimum reaction conditions, we got a series of optically active1,2-Dihydronaphthofurans with excellent enantioselectivities(up to91%ee) and yields(up to93%), as well as widely use of there reaction substrate.Withing X-ray diffraction, we determined the molecular configuration. As a result of experiment that the use of chiral multiple catalysts in asymmetric synthesis was a new emerging trend and the more applications of synthesis with chiral drugs.In addition, a series of antimicrobial activity sprio[thiophane-3-ol] derivatives were synthesized by the formal [3+2] cyclization reaction of3-arylidene(thio)chroman-4-ones and1,4-disulfide-2,5-diol. The reaction had been come true without catalyst involving the ethyl alcohol as solvent. Meanwhile, we also have successfully demonstrated that first asymmetric synthesis with chiral quaternary ammonium salts as organocatalysts. The corresponding products were obtained in good enantioselectivities and yields.The absolute configuration of adducts was confirmed by the single-crystal X-ray analysis.Ultimately, the asymmetric Micheal/Cyclization domino reaction of isothiocyanato oxindoles with benzopyran derivatives had also been investigated by bifunctional organocatalytic. Withing the effects of various reaction conditions studied, we synthesized a series of optically active multicyclic spirooxindoles smoothly. Meanwhile, the absolute configuration of product was unambiguously determined by X-ray crystallography.