The reaction of formaldehyde with β-diketones (Hantzsch reaction) has been often employed for derivatizing formaldehyde to the fluorescent compounds.1,2 Among βdiketones, 5,5-dimethyl-1,3-cyclohexanedione (dimedone, Fig. 1) seems to be the most promising because of the strong fluorescence intensity and stability of the formed compound. Recently, we developed a method for concentrating trace hyd...

This article describes one-pot synthesis of new fluorinated hexahydroquinoline derivatives via unsymmetric Hantzsch reaction involving 5-trifluoromethyl-1,3cyclohexanedione, aldehydes, acetoacetate ester, and ammonium acetate in trifluoroethanol (TFE). The reaction is simple and rapid with high yield.

The direct reductive amination of aromatic aldehydes has been achieved with excellent isolated yields (89-96%) using readily accessible Ph(3)PAuCl/AgOTf catalyst along with ethyl Hantzsch ester as hydrogen source under mild reaction conditions.

An eco-friendly "on-water" protocol for efficient catalyst-free synthesis of the Hantzsch dihydropyridines from aryl, heteroaryl, alkyl, and vinylogous aldehydes has been developed with minimum auxiliary substances, toxic reagents, organic solvents, and disposal problems.

A convenient protocol for the enantioselective synthesis of 4-substituted tetrahydroquinolines has been developed. Chiral BINOL phosphoric acids promote the reduction of a wide range of 4-substituted quinolines with Hantzsch esters with good to high levels of enantioselectivity.

A series of dihydropyridines were identified that have an effect on the accumulation of tau, an important target in Alzheimer's disease. The dihydropyridine collection was expanded using the Hantzsch multicomponent reaction to develop preliminary structure-activity relationships.

The synthesis of various substituted Biginelli 3,4-dihydropyrimidinone/thione and Hantzsch 1,4dihydropyridine derivatives has been achieved using a modified procedure in the presence of potassium ter-butoxide (tBuOK) as a catalyst under solvent-free conditions, in good to excellent yields.

an efficient one pot multi component synthesis of 1, 4-polyhydroquinoline derivatives through unsymmetrical hantzsch reaction using lanthanum chloride heptahydrate (lacl3.7h2o) from an aromatic aldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a nitrogen precursor in ethanol at room temperature is described. in the present work we report lanthanum chloride heptahydrate remarkably n...