23844-66-8Relevant articles and documents
Direct reductive amination of ketones with ammonium salt catalysed by Cp*Ir(iii) complexes bearing an amidato ligand
Dai, Zengjin,Pan, Ying-Min,Wang, Shou-Guo,Yin, Qin,Zhang, Xumu
supporting information, p. 8934 - 8939 (2021/11/04)
A series of half-sandwich Ir(iii) complexes1-6bearing an amidato bidentate ligand were conveniently synthesized and applied to the catalytic Leuckart-Wallach reaction to produce racemic α-chiral primary amines. With 0.1 mol% of complex1, a broad range of ketones, including aryl ketones, dialkyl ketones, cyclic ketones, α-keto acids, α-keto esters and diketones, could be transformed to their corresponding primary amines with moderate to excellent yields (40%-95%). Asymmetric transformation was also attempted with chiral Ir complexes3-6, and 16% ee of the desired primary amine was obtained. Despite the unsatisfactory enantio-control achieved so far, the current exploration might stimulate more efforts towards the discovery of better chiral catalysts for this challenging but important transformation.
General and selective synthesis of primary amines using Ni-based homogeneous catalysts
Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Jiao, Haijun,Murugesan, Kathiravan,Wei, Zhihong
, p. 4332 - 4339 (2020/05/18)
The development of base metal catalysts for industrially relevant amination and hydrogenation reactions by applying abundant and atom economical reagents continues to be important for the cost-effective and sustainable synthesis of amines which represent highly essential chemicals. In particular, the synthesis of primary amines is of central importance because these compounds serve as key precursors and central intermediates to produce value-added fine and bulk chemicals as well as pharmaceuticals, agrochemicals and materials. Here we report a Ni-triphos complex as the first Ni-based homogeneous catalyst for both reductive amination of carbonyl compounds with ammonia and hydrogenation of nitroarenes to prepare all kinds of primary amines. Remarkably, this Ni-complex enabled the synthesis of functionalized and structurally diverse benzylic, heterocyclic and aliphatic linear and branched primary amines as well as aromatic primary amines starting from inexpensive and easily accessible carbonyl compounds (aldehydes and ketones) and nitroarenes using ammonia and molecular hydrogen. This Ni-catalyzed reductive amination methodology has been applied for the amination of more complex pharmaceuticals and steroid derivatives. Detailed DFT computations have been performed for the Ni-triphos based reductive amination reaction, and they revealed that the overall reaction has an inner-sphere mechanism with H2metathesis as the rate-determining step.
Rapid and Quantitative Profiling of Substrate Specificity of ω-Transaminases for Ketones
Han, Sang-Woo,Shin, Jong-Shik
, p. 3287 - 3295 (2019/06/21)
ω-Transaminases (ω-TAs) have gained growing attention owing to their capability for asymmetric synthesis of chiral amines from ketones. Reliable high-throughput activity assay of ω-TAs is essential in carrying out extensive substrate profiling and establishing a robust screening platform. Here we report spectrophotometric and colorimetric methods enabling rapid quantitation of ω-TA activities toward ketones in a 96-well microplate format. The assay methods employ benzylamine, a reactive amino donor for ω-TAs, as a cosubstrate and exploit aldehyde dehydrogenase (ALDH) as a reporter enzyme, leading to formation of benzaldehyde detectable by ALDH owing to concomitant NADH generation. Spectrophotometric substrate profiling of two wild-type ω-TAs of opposite stereoselectivity was carried out at 340 nm with 22 ketones, revealing subtle differences in substrate specificities that were consistent with docking simulation results obtained with cognate amines. Colorimetric readout for naked eye detection of the ω-TA activity was also demonstrated by supplementing the assay mixture with color-developing reagents whose color reaction could be quantified at 580 nm. The colorimetric assay was applied to substrate profiling of an engineered ω-TA for 24 ketones, leading to rapid identification of reactive ketones. The ALDH-based assay is expected to be promising for high-throughput screening of enzyme collections and mutant libraries to fish out the best ω-TA candidate as well as to tailor enzyme properties for efficient amination of a target ketone.
