In this study, multi component Hantzsch reaction was carried out between various  Aromatic Aldehyde with Dimedone,Ethyl acetateand ammonium acetate to produce polyhydroquinolinederivatives under solvent-free conditions at 110oC by a (Zinc oxide  nanocatalyst) as effective Lewis acid. The remarkable advantages offered by this method compared with other methods are a green catalyst, simple work-u...

An enantioselective Friedel–Crafts reaction with aliphatic ketimines generated in situ from hemiaminal ethers catalyzed by a chiral Brønsted acid was investigated. The reaction of 2-methoxyfuran with (thio) hydantoin-derived hemiaminal methyl ether proceeded under the influence of a chiral phosphoric acid catalyst to afford the corresponding adduct possessing a quaternary stereogenic center in ...

TiCl2/nano-γ-Al2O3 as a new heterogeneous Lewis acid catalyst was synthesized and characterized by FE-SEM, XRD, FT-IR, EDS, XRF, BET and TGA. N-substituted pyrroles have been synthesized via Paal–Knorr reaction in the presence of TiCl2/nano-γ-Al2O3 at room temperature under solvent-free conditions.

Graphitic-C3N4 is shown for the first time to catalyse photoacetalization of aldehydes/ketones with alcohols to acetals in high yields using visible light under ambient conditions; transient charge separation over the material is effective to catalyse the reaction in the absence of Lewis or Brønsted acids, giving a new green alternative catalyst.

Organocatalysis, the catalysis with low-molecular weight catalysts where a metal is not part of the catalytic principle, can be as efficient and selective as metalor biocatalysis. Important discoveries in this area include novel Lewis base-catalyzed enantioselective processes and, more recently, simple Brønsted acid organocatalysts that rival the efficiency of traditional metal-based asymmetric...

An enantioselective PdII /Brønsted acid-catalyzed carbonylative carbocyclization of enallenes ending with a cross-dehydrogenative coupling (CDC) with a terminal alkyne was developed. VAPOL phosphoric acid was found as the best co-catalyst among the examined 28 chiral acids, for inducing the enantioselectivity of α-chiral ketones. As a result, a number of chiral cyclopentenones were easily synth...

A rapid and efficient one-pot, four-component protocol towards the synthesis of polyhydroquinoline derivatives has been developed. The condensation of aldehyde, dimedone, ethyl acetoacetate and ammonium acetate in presence of stannous chloride was carried out under solvent free condition to synthesize a variety of polyhydroquinoline derivatives in good to excellent yields. Stannous chloride was...

A rapid and efficient one-pot, four-component protocol towards the synthesis of polyhydroquinoline derivatives has been developed. The condensation of aldehyde, dimedone, ethyl acetoacetate and ammonium acetate in presence of stannous chloride was carried out under solvent free condition to synthesize a variety of polyhydroquinoline derivatives in good to excellent yields. Stannous chloride was...

Brønsted or Lewis acid assisted activation of an imidogold precatalyst (L-Au-Pht, Pht = phthalimide) offers a superior way to generate cationic gold compared with the commonly used silver-based system. It is also broadly applicable for most common gold-catalyzed reactions. For reactions that require milder conditions, milder acids can be used for optimized efficiency.

TiCl2/nano-γ-Al2O3 as a new heterogeneous Lewis acid catalyst was synthesized and characterized by FE-SEM, XRD, FT-IR, EDS, XRF, BET and TGA. N-substituted pyrroles have been synthesized via Paal–Knorr reaction in the presence of TiCl2/nano-γ-Al2O3 at room temperature under solvent-free conditions.