Related Experiment Video
Updated: Sep 30, 2025

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Direct Asymmetric Reductive Amination of Alkyl (Hetero)Aryl Ketones by an Engineered Amine Dehydrogenase
Weixi Kong1, Yunting Liu1, Chen Huang1
1School of Chemical Engineering and Technology, Hebei University of Technology, No. 8 Guangrong Road, Hongqiao District, Tianjin, 300130, China.
Abstract:
The direct asymmetric reductive amination of heteroaryl ketones has been a long-standing synthetic challenge. Here we report the engineering of an amine dehydrogenase (AmDH) from Jeotgalicoccus aerolatus for the asymmetric synthesis of chiral α-(hetero)aryl primary amines in excellent conversions (up to 99 %) and enantioselectivities (up to 99 % ee). The best AmDH variant (Ja-AmDH-M33 ) exhibited high activity and specificity toward alkyl (hetero)aryl ketones, even for those bearing a bulky alkyl chain. An efficient directed evolution approach based on molecular docking was implemented to enlarge the active pocket with a more hydrophobic entrance, which is responsible for the high activity. The Ja-AmDH-M33 was also used for preparative-scale synthesis of pharmaceutically relevant amines and a key intermediate of chiral pincer ligands, which highlighted its practical application in synthetic chemistry.
Related Concept Videos
Preparation of Amines: Reductive Amination of Aldehydes and Ketones
Preparation of Amines: Reduction of Amides and Nitriles
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Amides to Amines: LiAlH4 Reduction
Amide reduction requires two equivalents of the reducing agent, acting as a source of hydride ions. As shown in the figure, the reaction is initiated with a nucleophilic attack by the hydride ion at the carbonyl carbon to form a tetrahedral intermediate.
Nitriles to Amines: LiAlH4 Reduction
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...

