Synthesis Of Multi-spiroindole-pyran And Multi-substituted Pyran Compounds Via One-pot Multi-component Reaction

Heterocycles containing pyrazole, indole and pyran rings are important target compounds in synthetic and medicinal chemistry because the ring is a key moiety in various biologically active compounds. They have been studied in the development of insecticides, acaricides, fungicides, herbicides, dyes, and reagents b. Spirooxindoles exhibit a wide range of biological properties. Pyran derivatives exhibit a wide range of biological and physical properties, spiropyran, has excellent optical propertiesMulti-component reactions(MCRs) effectively combine three, or sometimes more, reactants simultaneously in a one-pot synthesis that does not require the separation of intermediate products. These reactions constitute one of the best tools for modern organic synthesis because they can use most of the constituent atoms of several reactant molecules to form a product molecule. They are also highly selective and are simply operated under mild conditions; some have been used industrially. MCRs have been widely used in synthetic chemistry to form new carbon–carbon bonds.The chapter one was a introduction to introduced the MCRs and pyran, pyrazole, indole, spirooxindole-pyrano[2,3-c] pyrazole.The chapter two was introduced CeCl3-catalyzed multi-component one-pot reactions for the convenient synthesis of 6-amino-5-cyano-4-aryl-4H-pyran derivatives. An ef?cient and clean reaction process of β-Ketoesters, aromatic aldehyde, and malononitrile was developed for the convenient and cheap synthesis of 6-amino-5-cyano-4-aryl-4H-pyran derivatives. This reaction was conducted in EtOH in the presence of CeCl3 as a catalyst in a good yield.The chapter three was introduced 4-dimethylaminopyridine-catalyzed multi-component one-pot reactions for the convenient synthesis of spirooxindole-pyrano[2,3-c] pyrazole.An ef?cient, clean, and environmentally benign reaction process was developed for the convenient and cheap synthesis of spirooxindole derivatives. One-pot reactions of isatins, malononitrile(or ethyl cyanoacetate), hydrazine hydrate(or phenylhydrazine), and 1,3-dicarbonyl compounds were compared with one-pot reactions of isatins, malononitrile(or ethyl cyanoacetate), and 5-pyrazolone derivatives. Both sets of reaction were conducted in EtOH in the presence of 4-DMAP catalyst. A series of spirooxindole-pyrano[2,3-c] pyrazole derivatives was quickly obtained in excellent yields.The chapter four was introduced DIPEA-catalyzed multi-component one-pot reactions for the convenient synthesis of spirooxindole-pyrano[2,3-c] pyrazole. A highly efficient strategy to multi-substituted spiroindole-pyran derivative via four-component one-pot method with acetylenedicarboxylate, hydrazine, isatin and 1-methylthio-1-methylamino-2-nitroethylene catalysed by DIPEA. This method were further compound the spiroindole-pyran derivative and all of target compounds were conducted in EtOH in the presence of DIPEA catalyst. A series of spiroindole-pyran derivative were obtained in a good yields.