نتایج جستجو برای: hantzsch condensation

تعداد نتایج: 32606  

Journal: :Organic letters 2014
Zhengxu S Han Yibo Xu Daniel R Fandrick Sonia Rodriguez Zhibin Li Bo Qu Nina C Gonnella Sanjit Sanyal Jonathan T Reeves Shengli Ma Nelu Grinberg Nizar Haddad Dhileep Krishnamurthy Jinhua J Song Nathan K Yee Waldemar Pfrengle Markus Ostermeier Jürgen Schnaubelt Zeno Leuter Sonja Steigmiller Jürgen Däubler Emanuel Stehle Lukas Neumann Thomas Trieselmann Patrick Tielmann Annette Buba Rainer Hamm Gunter Koch Svenja Renner Juan R Dehli Florian Schmelcher Christian Stange Jürgen Mack Rainer Soyka Chris H Senanayake

An efficient enantioselective synthesis of the chiral polycyclic cholesteryl ester transfer protein (CETP) inhibitor 1 has been developed. The synthesis was rendered practical for large scale via the development of a modified Hantzsch-type reaction to prepare the sterically hindered pyridine ring, enantioselective hydrogenation of hindered ketone 6 utilizing novel BIBOP-amino-pyridine derived R...

Journal: :journal of sciences islamic republic of iran 0

hantzsch 1,4-dihydropyridines are oxidized to the corresponding pyridine derivatives using oxygen or air and a mixture of the manganese and cobalt salts of parninobenzoic acid supported on silica gel as the catalysts. reactions are clean and the catalysts can be recovered easily and reused repeatedly.

Gholamreza Karimipour, Massomeh Bahramian Zahra Rafiee

In this work, a polyimide (PI) containing triazole units was synthesized using 3,5-diamino-1,2,4-triazole and pyromellitic dianhydride in N-methyl-2-pyrrolidinone. This polymer was used as the support of manganese (III) tetrakis(4-methoxylphenyl)porphyrin acetate to attain a heterogeneous catalyst; namely Mn(T4-OMePP)OAc@PI. The synthesized PI and Mn(T4-OMePP)OAc@PI were characterized by di...

Herein, it has been shown that the bismuth ferrite magnetic nanoparticles (BFO-MNPs) are new, efficient and recyclable catalysts for the synthesis of polyhydroquinoline derivatives by the Hantzsch reaction. The one-pot four-component cyclocondensation reaction of dimedone, aromatic aldehydes, ethyl acetoacetate and ammonium acetate was carried out under solvent-free conditions. The...

Hantzsch 1,4-dihydropyridines are oxidized to the corresponding pyridine derivatives using oxygen or air and a mixture of the manganese and cobalt salts of parninobenzoic acid supported on silica gel as the catalysts. Reactions are clean and the catalysts can be recovered easily and reused repeatedly.

2005
T. J. Still S. Al-Haider P. W. Seakins R. Sommariva J. C. Stanton G. Mills S. A. Penkett

Ambient formaldehyde measurements made at a remote marine boundary layer site during the NAMBLEX campaign – a comparison of data from chromatographic and modified Hantzsch techniques T. J. Still, S. Al-Haider, P. W. Seakins, R. Sommariva, J. C. Stanton, G. Mills, and S. A. Penkett School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK School of Environmental Sciences, University of East A...

Journal: :Organic & biomolecular chemistry 2008
Dhevalapally B Ramachary Y Vijayendar Reddy B Veda Prakash

The amino acid proline catalyzed the three- and five-component cascade olefination-Diels-Alder-epimerization and olefination-Diels-Alder-epimerization-olefination-hydrogenation reactions of readily available precursors enones 1a-i, arylaldehydes 2a-k, alkyl cyanoacetates 3a-e and Hantzsch ester 9 to furnish highly substituted prochiral 1-cyano-4-oxo-2,6-diaryl-cyclohexanecarboxylic acid alkyl e...

2010
Santos Fustero María Sánchez-Roselló Carlos del Pozo

The use of domino and multicomponent reactions in asymmetric synthesis is constantly increasing nowadays. This allows for the synthesis of complex molecules in a single synthetic sequence, usually with high atom economy. Herein, we report three examples of new asymmetric tandem reactions recently developed in our laboratories, giving rise to new families of enantiomerically enriched fluorinated...

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