نتایج جستجو برای: mixed amines

تعداد نتایج: 240806  

Journal: :The Journal of biological chemistry 1996
K Wimalasena S Dharmasena D S Wimalasena D K Hughbanks-Wheaton

The interactions of reductants with dopamine beta-monooxygenase (DbetaM) were examined using two novel classes of reductants. The steady-state kinetics of the previously characterized DbetaM reductant, N,N-dimethyl-1,4-p-phenylenediamine (DMPD), were parallel to the ascorbic acid-supported reaction with respect to pH dependence and fumarate activation. DMPD also displayed pH and fumarate-depend...

Journal: :Chemical communications 2011
Boram Lee Rosario Scopelliti Kay Severin

A coumarin derivative was employed for the detection of biogenic amines in buffered aqueous solution by UV-Vis or fluorescence spectroscopy. Incorporated in a polymeric matrix, the dye can also be used for the optical detection of gaseous amines.

Journal: :Chemical communications 2010
Guofu Zi Furen Zhang Haibin Song

A highly enantioselective group 5 metal amide catalyst system is reported for the hydroaminoalkylation of secondary amines to give chiral amines in good yields with excellent ee values (up to 93%) by loading of 5% precatalyst.

Journal: :Chemical communications 2014
Thomas Lebleu Xiaolu Ma Jacques Maddaluno Julien Legros

Direct monomethylation of primary amines with methyl triflate was achieved with high selectivity (up to 96%). The key point of this single methyl transfer stems from the use of HFIP as the solvent that interferes with amines and avoids overmethylation.

Journal: :Organic & biomolecular chemistry 2011
Qiang Kang Yugen Zhang

Aza-Michael addition of amines, including aromatic and aliphatic amines, with α, β-unsaturated ketones was realized employing N-Heterocyclic Carbene (NHC) as organocatalyst, yielding β-amino ketones with up to 98% yield.

The one-pot synthesis of symmetrical triaryl amines using aryl halides and 5-Methyl-1,3,4-Thiadiazole-2-Amine as a nitrogen-transfer reagent is reported. Copper oxide nanoparticles that does not require the presence of any additional ligand, improved rate and facility of the synthesis of triaryl amines. The introduction of a new N-source, using green solvents PEG/H2O, normal atmospheric conditi...

A simple, efficient, and cost-effective procedure for the N-tert-butoxycarbonylation and N-formylation of amines (primary, secondary) respectively, with di-tert-butyl dicarbonate and 85% aqueous formic acid under solvent-free condition using B(OSO3H)3/SiO2 (SBSA) as a heterogeneous and recyclable catalyst has been developed. We demonstrated that the resulting catalyst is applicable to various a...

Journal: :Chemical communications 2009
Phillip A Shelton Yue Zhang Thi Hoang Ha Nguyen Lisa McElwee-White

Oxidative carbonylation of amines using NaIO(4) as the oxidant and NaI as a promoter affords good to excellent yields of ureas from primary amines in the absence of transition metal catalysts.

Journal: :Chemical communications 2010
Lingling Chu Feng-Ling Qing

The benzoyl peroxide (BPO)-promoted oxidative functionalization of tertiary amines under transition-metal-free reaction conditions was developed. Various 1-trifluoromethylated tetrahydroisoquinoline derivatives were prepared by employing this method. It constitutes the first example of direct trifluoromethylation of tertiary amines.

2001
S. Pizzarello

L-enantiomeric excesses have been determined for some amino acids of the Murchison and Murray meteorites [1-4]. The finding has taken a particular significance in view of the homochiral distribution of biochemical molecules and the possible contribution of asymmetry-carrying organics to the early Earth by meteorite and cometary delivery. So far, evidence of nonracemic compounds in meteorites ha...

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