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A novel chiral ammonia borane was designed and developed via the dehydrogenation of ammonia borane with chiral phosphoric acid, which was highly effective for the asymmetric transfer hydrogenation of imines and β-enamino esters to afford high levels of reactivities and enantioselectivies. Significantly, this chiral ammonia borane can be continuously regenerated during the transfer hydrogenation with the assistance of water and ammonia borane, which allowed as low as 0.1 mol % of chiral phosphoric acid to give satisfactory results. Notably, the role of chiral phosphoric acid is to produce the chiral ammonia borane.
This article was published in the following journal.
Name: Angewandte Chemie (International ed. in English)
The first example of metal-free B(C6F5)3-catalyzed asymmetric reduction amination of ketones with chiral α-methylbenzylamine (α-MBA) using ammonia borane as the reductant is reported. This one-pot m...
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Polymers of N-SUBSTITUTED GLYCINES containing chiral centers at the a-position of their side chains. These oligomers lack HYDROGEN BONDING donors, preventing formation of the usual intrachain hydrogen bonds but can form helices driven by the steric influence of chiral side chains.
An inhibitor of nitric oxide synthetase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. (Neurochem Res 1995:200(4):451-6)
An enzyme that catalyzes the formation of asparagine from ammonia and aspartic acid, in the presence of ATP. EC 184.108.40.206.
The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.
Elevated level of AMMONIA in the blood. It is a sign of defective CATABOLISM of AMINO ACIDS or ammonia to UREA.