نتایج جستجو برای: 2 diamines

تعداد نتایج: 2526582  

2015
Liliang Huang Chengxiang He Zhihua Sun

Chan-Lam cross coupling allowed efficient synthesis of N,N'-disubstituted ortho-phenylene diamines bearing strong electron donating or withdrawing groups, such as nitro or methoxy groups, with moderate to high yields. These diamines can then be turned into N-heterocyclic carbene precursors after condensation with trimethyl orthoformate. The same strategy can also be utilized for the synthesis o...

Journal: :Molecules 2011
Sha-Sha Kan Jian-Zhen Li Cheng-Yan Ni Quan-Zhong Liu Tai-Ran Kan

Highly efficient asymmetric aldol reactions between α,β-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of substrates were tolerable in the present catalytic system.

Journal: :ChemistrySelect 2022

A new method for the synthesis of bis(1,3,5-triazine-2,4-diamines) was developed using a one-pot multicomponent approach. The performed acid-catalyzed reaction cyanoguanidine with amines and aldehydes, followed by dehydrogenative aromatization dihydrotriazine intermediates upon heating alkali. Two types were prepared either piperazine as bifunctional amine or terephthaldehyde aldehyde thus affo...

Journal: :Journal of AOAC International 2003
Patricia L Rogers Walter F Staruszkiewicz Ronald A Benner

A gas-liquid chromatographic method developed for the determination of putrescine and cadaverine in fishery products was modified for application to the determination of diamines in shrimp. Addition of potassium chloride and hydrochloric acid to the methanol-water extraction solvent resulted in increased recovery of the diamines and minimized gel formation. The recovery of putrescine increased ...

2018
Vijayakumar K Sountharrajan S Suganya E

Anticancer approaches may employ change of molecular structure to enhance preventive influence of chemical agents. The present examination concerned the potential anticancer impact of modified heterocyclic compounds. A strategy was developed to combine tetrazole moieties from different diamines with 2-aminobenzoic and substituted benzoyl chloride compounds with attention to synthesis, character...

Journal: :Chemical communications 2014
Guiyang Li Biao Zhang Jun Yan Zhonggang Wang

Tetraphenyladamantane-based porous poly(Schiff base)s with BET surface area (>1000 m(2) g(-1)), CO2 uptake (15 wt%, 273 K/1 bar) and H2 uptake (1.26 wt%, 77 K/1 bar) were synthesized. The structure-directing effect of isomers of phenyl diamines on building porous architecture was investigated.

Journal: :journal of sciences islamic republic of iran 0

2,2'-disubstitutedamino-4-4'-bis-pyrimidines (3a-m) have been prepared by linking 2,4-dichloro-6-methyl-5-nitropyrimidine (1) with several diamines and subsequent reaction with suitable amines. some of these compounds (3c and 3j) which were reduced catalitically, on treatment with nitrous acid, urea in pyridine, and boiling thionyl chloride gave the corresponding bistriazolopyrimidin ...

Journal: :Chemical Communications 2021

We present here the first example of direct synthesis polyureas from dehydrogenative coupling diamines and methanol.

Journal: :Chemical science 2015
Kun Shen Qiu Wang

A copper-catalyzed regio- and stereoselective diamination of unactivated alkenes has been developed with O-acylhydroxylamines as electrophilic nitrogen sources and oxidants. This method provides the first example of metal-catalyzed alkene diamination for directly installing an electron-rich amino group and extends the diamination scope for the synthesis of diverse 1,2-diamines. It offers a rapi...

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