نتایج جستجو برای: hantzsch condensation

تعداد نتایج: 32606  

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2002
mahammad mahmoodi hashemi yousef ahmadibeni

the polymer supported hypochlorite ion is a facile selective oxidizing agent for the oxidation of various alcohols to aldehydes and ketones. similarly is successfully oxidizes various hantzsch type 1,4- dihydropyridines to corresponding pyridines.

Journal: :Chemical communications 2015
Emilie Martinelli Anna Chiara Vicini Michele Mancinelli Andrea Mazzanti Paolo Zani Luca Bernardi Mariafrancesca Fochi

In the presence of a thiourea catalyst, β-CF3 nitroalkenes react with Hantzsch esters in a highly enantioselective fashion, giving a broad range of β-CF3 amine precursors with a tertiary stereocentre at the β-position. This reaction represents the first general catalytic enantioselective approach to this important class of β-CF3 amines.

Journal: :Chemical communications 2015
Avijit Jana John Mondal Parijat Borah Sujan Mondal Asim Bhaumik Yanli Zhao

A versatile heterogeneous photocatalysis protocol was developed by using ruthenium bipyridyl tethered porous organosilica (Ru-POS). The versatility of the Ru-POS catalyst in organo-photocatalysis was explored by (i) oxidative aromatization of Hantzsch ester, (ii) reductive dehalogenation of alkyl halides, and (iii) functional group interconversion (FGI) of alcohols to alkyl halides.

Journal: :Chemical communications 2012
Mu-Wang Chen Qing-An Chen Ying Duan Zhi-Shi Ye Yong-Gui Zhou

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.

Journal: :Organic letters 2009
Christopher G Evans Jason E Gestwicki

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...

Journal: :Chemical communications 2011
Nadiya Koukabi Eskandar Kolvari Ardeshir Khazaei Mohammad Ali Zolfigol Behzad Shirmardi-Shaghasemi Hamid Reza Khavasi

A magnetic nanoparticle catalyst was readily prepared from inexpensive starting materials which catalyzed the Hantzsch reaction. High catalytic activity and ease of recovery from the reaction mixture using an external magnet, and several reuse times without significant losses in performance are additional eco-friendly attributes of this catalytic system.

Journal: :Chemical communications 2014
Mu-Wang Chen Xian-Feng Cai Zhang-Pei Chen Lei Shi Yong-Gui Zhou

An efficient and facile route to chiral tetrahydroquinolines with three contiguous stereogenic centers via a dynamic kinetic resolution process has been successfully developed by using chiral phosphoric acid as catalyst and Hantzsch ester as the hydrogen source with up to 89% ee.

Journal: :Chemical Communications 2021

The Hantzsch reaction was adapted to allow the rapid radiosynthesis of 13N-labelled 1,4-dihydropyridines, including [13N]nifedipine, for preclinical PET imaging.

Journal: :Journal of the American Chemical Society 2008
Guillaume Barbe André B Charette

This communication describes the chemoselective metal-free reduction of tertiary amides to the corresponding amines. Hantzsch ester is used as a mild reducing agent for the reduction of trifluoromethanesulfonic anhydride activated amides providing the tertiary amines with high functional group tolerance.

2006
T. J. Still S. Al-Haider P. W. Seakins R. Sommariva J. C. Stanton G. Mills S. A. Penkett

Ambient formaldehyde concentrations are reported from the North Atlantic Marine Boundary Layer Experiment (NAMBLEX) campaign at Mace Head on the west coast of Eire during August 2002. The results from two techniques, using direct determination via gas chromatography and the Hantzsch technique, show similar trends but a significant off set in concentrations. For westerly air flows characteristic...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید