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Updated: Jun 13, 2025

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
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Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine

Published on: February 16, 2018

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由低能共振电子附着启动的谷氨酸的反体形式的电子驱动过程

Stanislav A Pshenichnyuk1, Nail L Asfandiarov1, Rustam G Rakhmeyev1

  • 1Institute of Molecule and Crystal Physics, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa, Russia.

The Journal of chemical physics
|September 16, 2024
PubMed
概括

谷氨酸的离散电子附着 (DEA) 显示出独特的碎片离子,与其他氨基酸不同. 在当前的实验条件下,电子与L-和D-谷氨酸的相互作用显示了相同的光谱.

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Stereochemical Effects of Enolization

The chiral α-carbon of the carbonyl compound is the stereocenter of the molecule. As shown in the figure below, when such a carbonyl compound undergoes racemization under an acidic or basic condition, an achiral enol is formed.
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Regioselective Formation of Enolates

As depicted in the figure below, the unsymmetrical ketones can form two possible enolates:  less substituted or more substituted enolates. Usually, the thermodynamic enolates are formed from the more substituted α-carbon atom, while the kinetic enolates are formed faster by deprotonation from the less substituted position. The thermodynamic enolates have lower energy, so they are  more stable. But the energy required to form kinetic enolates is less.
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Enolate ions are formed by the acid–base reaction of a carbonyl compound with a base. This leads to deprotonation of the α hydrogen atom, leading to a resonance-stabilized enolate ion where one of the contributing structures is an oxyanion, which imparts additional stability. Therefore, the proton on the α carbon is more acidic in nature than that of other sp3-hybridized C–H bonds but less acidic than those in O–H bonds where the negative charge in the conjugate...
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