A straightforward enantiomerically pure synthesis of the heterocyclic core of the D-series GE2270 is reported. The synthetic strategy combines the Hantzsch thiazole's building condensation with a cross-coupling reaction including direct C-H hetarylation to build and connect step-by-step thiazolyl moieties to the 5-bromopicolinate as readily available starting material.

Asymmetric hydrogenolysis of racemic tertiary alcohols, 3-substituted 3-hydroxyisoindolin-1-ones, was developed using chiral phosphoric acid as catalyst and a Hantzsch ester as the hydrogen source with up to 95% ee. The reaction process of this asymmetric transfer hydrogenation may occur directly through the acyliminium ion intermediate.

The four-component Hantzsch reaction provides access to pharmaceutically important dihydropyridines. To expand the utility of this method, we have developed a route under organocatalytic conditions with good yields and excellent ee's. Through catalyst screening, we found that a BINOL-phosphoric acid allowed enantioselective synthesis of six-membered heterocycles with a variety of substitution p...

A novel and green approach for efficient and rapid synthesis of biologically active polyhydroquinoline derivatives via unsymmetric Hantzsch reaction using nanorods Vanadatesulfuric acid (VSA NRs) as a new and recyclable catalyst under solvent-free conditions was reported. The catalyst was characterized by FT-IR, XRD, XRF and TEM analysis. The present method offers several advantages such as sim...

Thiophene containing thiazolyl carbohydrazide on reaction with various aryl isothiocynates yields thiosemicarbazides which were transformed into 1,2,4- substituted thiazoles by Hantzsch synthesis and characterized spectral methods. Most of the synthesized new are found to be promisingly effective against tested bacterial strains exhibited moderate activitytested fungal strains. 1, 2,4- weakly a...

A new synthetic approach to polyfunctional hexahydropyrrolo[3,4-b]pyrroles was developed based on cyclization of N-arylbromomaleimides with aminocrotonic acid esters. A highly chemo- and stereoselective reaction is a Hantzsch-type domino process, involving the steps of initial nucleophilic C-addition or substitution and subsequent intramolecular nucleophilic addition without recyclyzation of im...

Phosphosulfonic acid (PSA) was found to be an efficient catalyst for the one-pot three-component Hantzsch condensation reaction of arylaldehydes, ethylacetoacetate and ammonium acetate to afford the corresponding 1,4-dihydropyridine and polyhydroquinoline derivatives in high yields. PSA was also applied for the one-pot preparation of polyhydroquinolines via four-component reaction of a...

A reinvestigation of a chiral phosphoric-acid-catalyzed four-component Hantzsch enantioselective synthesis polyhydroquinolines reported in 2009 is presented. In our hands, when the reaction was performed with fidelity to original report using enantiopure phosphoric acid catalyst, no enantioselectivity observed. Unlike report, results are backed by baseline separation enantiomers HPLC analyses o...

phosphosulfonic acid (psa) was found to be an efficient catalyst for the one-pot three-component hantzsch condensation reaction of arylaldehydes, ethylacetoacetate and ammonium acetate to afford the corresponding 1,4-dihydropyridine and polyhydroquinoline derivatives in high yields. psa was also applied for the one-pot preparation of polyhydroquinolines via four-component reaction of arylaldehy...

sulfonic acid functionalized sba-15 (sba-pr-so3h) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. sba-pr-so3h was proved to be an efficient heterogeneous ...