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PANI (polyaniline)-g-C3N4-TiO2 composite was prepared and found to be efficient for the synthesis of 2,5-diaryl 1,3,4-oxadiazoles under visible light. This reaction involved decarboxylation and cyclization from α-keto acids with acylhydrazines, and a broad scope of substrates were tolerated to provide the desired products in moderate to good yields. Control experiments indicated that a radical pathway was involved in the present photocatalytic reaction and a synergistic effect may exist in the ternary composite. Moreover, this semiconductor photocatalyst could be readily recovered and showed good reusability with only slight decrease in the catalytic activity after six consecutive runs.

An efficient catalytic procedure has been developed for the aerobic oxidative dehydrogenation of N-heterocycles by cobalt porphyrin in the absence of any additives. The catalytic system could tolerate various 1,2,3,4-tetrahydroquinoline derivatives and some other N-heterocycles. The corresponding N-heteroaromatics could be obtained in 59–86% yields. The mechanism investigation suggested that the aerobic oxidative dehydrogenation might proceed with imine intermediate through radical paths.

TiO 2 /MoS 2 nanocomposite photocatalyst was prepared via simple one-step hydrothermal process. This nontoxic and inexpensive photocatalyst exhibited high activity toward the thiocyanation of indoles under visible light irradiation at room temperature. Simple work-up, good yields, as well as reusability of the catalyst are the major advantages of the present method.

The t-BuOK promoted stereoselective isomerization of allyl aryl ethers has been developed. The reactions proceeded well in methyl tert-butyl ether (MTBE), providing the corresponding products in good to excellent yields (83–96%). Most of the substrates were isomerized predominantly to the Z isomers with excellent stereoselectivities. Gram-scale synthesis was also achieved on a 10 mmol scale. Moreover, the cascade Cannizzaro and isomerization reactions, and the one-pot isomerization and styryl sulfide formation reactions, were also realized, affording a potential synthetic route to access interesting compounds.

An efficient and convenient heterogeneous catalytic system has been developed for the aerobic cross-dehydrogenative coupling over NiGa layered double oxide (Ni3Ga-LDO) without any additives. The results indicated that the catalytic system could tolerate various tetrahydroquinoline derivatives and nucleophiles using molecular oxygen as a sustainable oxidant. The catalyst could be recycled four times without significantly decrease of activity or change of XRD pattern, indicating that Ni3Ga-LDO was catalytically and structurally stable in the cross-coupling reaction.

An iron-catalyzed oxidative dehydrogenative coupling of ethers with aryl tetrazoles has been developed. A wide variety of tetrazoles and ethers survived the reaction conditions to deliver the corresponding hemiaminal derivatives in moderate to good yields.

An iron-catalyzed coupling reaction of methylarenes with thiols leading to thioesters has been developed. The reactions were carried out in water with tert-butyl hydroperoxide (TBHP) as the oxidant and polyoxyethanyl α-tocopheryl sebacate (PTS) as the surfactant. The reaction medium is compatible with a series of functional groups and can be reused.

An efficient and convenient heterogeneous catalytic procedure has been developed for the phosphonation of a-amino C H bonds with various dialkyl phosphites and diarylphosphine oxides using molecular oxygen as a sustainable oxidant over CoNiFe hydrotalcite. The catalytic system could tolerate various tetrahydroquinoline derivatives, and the corresponding a-amino phosphonic compounds could be obtained in good to excellent yields. Synergistic effect might exist in the oxidative phosphonation under the catalysis of CoNiFe hydrotalcite.