51773-65-0Relevant academic research and scientific papers
PQQ-dependent Dehydrogenase Enables One-pot Bi-enzymatic Enantio-convergent Biocatalytic Amination of Racemic sec-Allylic Alcohols
Gandomkar, Somayyeh,Rocha, Raquel,Sorgenfrei, Frieda A.,Montero, Lía Martínez,Fuchs, Michael,Kroutil, Wolfgang
, p. 1290 - 1293 (2020/12/23)
The asymmetric amination of secondary racemic allylic alcohols bears several challenges like the reactivity of the bi-functional substrate/product as well as of the α,β-unsaturated ketone intermediate in an oxidation-reductive amination sequence. Heading for a biocatalytic amination cascade with a minimal number of enzymes, an oxidation step was implemented relying on a single PQQ-dependent dehydrogenase with low enantioselectivity. This enzyme allowed the oxidation of both enantiomers at the expense of iron(III) as oxidant. The stereoselective amination of the α,β-unsaturated ketone intermediate was achieved with transaminases using 1-phenylethylamine as formal reducing agent as well as nitrogen source. Choosing an appropriate transaminase, either the (R)- or (S)-enantiomer was obtained in optically pure form (>98 % ee). The enantio-convergent amination of the racemic allylic alcohols to one single allylic amine enantiomer was achieved in one pot in a sequential cascade.
Iterative Alanine Scanning Mutagenesis Confers Aromatic Ketone Specificity and Activity of L-Amine Dehydrogenases
Mu, Xiaoqing,Wu, Tao,Mao, Yong,Zhao, Yilei,Xu, Yan,Nie, Yao
, p. 5243 - 5253 (2021/11/16)
Direct reductive amination of prochiral ketones catalyzed by amine dehydrogenases is attractive in the synthesis of active pharmaceutical ingredients. Here, we report the protein engineering of L-Bacillus cereus amine dehydrogenase to allow reactivity on synthetically useful aromatic ketone substrates using an iterative, multiple-site alanine scanning mutagenesis approach. Mutagenesis libraries based on molecular docking, iterative alanine scanning, and double-proximity filter approach significantly expand the scope of active pharmaceutical ingredients relevant building blocks. The eventual quintuple mutant (A115G/T136A/L42A/V296A/V293A) showed reactivity toward aromatic ketones 12 a (5-phenyl-pentan-2-one) and 13 a (6-phenyl-hexan-2-one), which have not been reported to serve as targets of reductive amination by currently available amine dehydrogenases. Docking simulation and tunnel analysis provided valuable insights into the source of the acquired specificity and activity.
Enzymatic Primary Amination of Benzylic and Allylic C(sp3)-H Bonds
Jia, Zhi-Jun,Gao, Shilong,Arnold, Frances H.
supporting information, p. 10279 - 10283 (2020/07/27)
Aliphatic primary amines are prevalent in natural products, pharmaceuticals, and functional materials. While a plethora of processes are reported for their synthesis, methods that directly install a free amine group into C(sp3)-H bonds remain unprecedented. Here, we report a set of new-to-nature enzymes that catalyze the direct primary amination of C(sp3)-H bonds with excellent chemo-, regio-, and enantioselectivity, using a readily available hydroxylamine derivative as the nitrogen source. Directed evolution of genetically encoded cytochrome P411 enzymes (P450s whose Cys axial ligand to the heme iron has been replaced with Ser) generated variants that selectively functionalize benzylic and allylic C-H bonds, affording a broad scope of enantioenriched primary amines. This biocatalytic process is efficient and selective (up to 3930 TTN and 96percent ee), and can be performed on preparative scale.
Sequential Two-Step Stereoselective Amination of Allylic Alcohols through the Combination of Laccases and Amine Transaminases
Albarrán-Velo, Jesús,Lavandera, Iván,Gotor-Fernández, Vicente
, p. 200 - 211 (2019/12/03)
A sequential two-step chemoenzymatic methodology for the stereoselective synthesis of (3E)-4-(het)arylbut-3-en-2-amines in a highly selective manner and under mild reaction conditions is described. The approach consists of oxidation of the corresponding racemic alcohol precursors by the use of a catalytic system made up of the laccase from Trametes versicolor and the oxy-radical TEMPO, followed by the asymmetric reductive bio-transamination of the corresponding ketone intermediates. Optimisation of the oxidation reaction, exhaustive amine transaminase screening for the bio-transaminations and the compatibility of the two enzymatic reactions were studied in depth in search of a design of a compatible sequential cascade. This synthetic strategy was successful and the combinations of enzymes displayed a broad substrate scope, with 16 chiral amines being obtained in moderate to good isolated yields (29–75 %) and with excellent enantiomeric excess values (94 to >99 %). Interestingly, both amine enantiomers can be achieved, depending on the selectivity of the amine transaminase employed in the system.
Deammoniative condensation of primary allylic amines with nonallylic amines
Wang, Yong,Li, Manbo,Ma, Xiantao,Liu, Congrong,Gu, Yonghong,Tian, Shi-Kai
, p. 741 - 751 (2014/10/15)
An unprecedented deammoniative condensation reaction of primary allylic amines with nonallylic amines has been developed through C-N bond cleavage. In the presence of 5 mol% palladium diacetate, 10 mol% 1,4-bis(diphenylphosphino) butane (dppb), and 5 mol% p-toluenesulfonic acid (TsOH), a range of α-unbranched primary allylic amines smoothly underwent deammoniative condensation with nonallylic amines in an α-selective fashion to give structurally diverse secondary and tertiary amines in good to excellent yields and E selectivity. Replacing dppb with racemic 2,2-bis(diphenylphosphino)-1,1- binaphthyl (BINAP) permitted the deammoniative condensation of enantioenriched α-chiral primary allylic amines with nonallylic amines to proceed with complete retention of configuration. Electrospray ionization (ESI) mass spectrometric analysis of the reaction mixture permitted the identification of some π-allylpalladium intermediates, and plausible mechanisms have been proposed to account for the regioselectivity and stereospecificity of the deammoniative condensation reaction. A range of enantioenriched primary allylic amines underwent palladium/acid-catalyzed direct substitution with nonallylic amines in a stereospecific manner. Copyright
Palladium-catalyzed aerobic oxidative coupling of enantioenriched primary allylic amines with sulfonyl hydrazides leading to optically active allylic sulfones
Wang, Ting-Ting,Wang, Fu-Xiang,Yang, Fu-Lai,Tian, Shi-Kai
supporting information, p. 3802 - 3805 (2014/04/03)
A range of highly enantioenriched primary allylic amines underwent palladium-catalyzed oxidative coupling with sulfonyl hydrazides open to air at room temperature to give structurally diverse allylic sulfones in moderate to excellent yields with excellent retention of ee. This journal is the Partner Organisations 2014.
Benzotriazole-Mediated Stereoselective Olefination of Carboxylic Esters: Transformation of α-Amino Acid Esters into Chiral Allylamines
Katritzky, Alan R.,Cheng, Dai,Li, Jianqing
, p. 3438 - 3444 (2007/10/03)
Diastereoselective trans-olefinations of carboxylic esters 3a-h have been accomplished using benzylic or allylic benzotriazole derivatives 1a-e to prepare α-(benzotriazol-1-yl) ketones 4a-i, for the subsequent reduction of 4a-i, and finally for low-valent titanium-effected dehydroxybenzotriazolylation.1 N-Protected α-amino acid esters 9a-c and 15 thus give allylamines 13a-e and 19 with virtually full retention of chirality. Mechanistic aspects of the dehydroxybenzotriazolylation are discussed.
Enantioselektive Synthese von Allyl-, Propargyl- und 4-En-2-inyl-aminen durch 1,2-Addition von Organocer-Reagenzien an chirale Aldimine
Enders, Dieter,Schankat, Juergen
, p. 970 - 992 (2007/10/02)
(E)- and (Z)-Allyl-, propargyl, and 4-en-2-ynyl-amines 5 and 14, useful bifunctional building blocks and of pharmaceutical interest, are synthesized in high enantiomeric purity (e.e. >/= 97 percent).Key step is the diastereoselective 1,2-addition (d.e. 86
Enantioselective Synthesis of Allyl- and Propargylamines via Nucleophilic 1,2-Addition to Chiral Aldimines
Enders, Dieter,Schankat, Juergen
, p. 402 - 406 (2007/10/02)
The asymmetric synthesis of allylamines and propargylamines 5 in high enantiomeric purity (e.e >/= 97percent) is described.Key step is the 1,2-addition of organocerium reagents to chiral α,β-unsaturated aldimines 3 to produce secondary amines 4.The chiral
WITTIG OLEFINATION IN THE ABSENCE OF AN EXOGENOUS BASE: A NEW SYNTHESIS OF α-SUBSTITUTED PRIMARY ALLYLIC AMINES
Dellaria, Joseph F.,Sallin, Kevin J.
, p. 2661 - 2664 (2007/10/02)
A new synthesis of α-substituted primary allylic amines through the in situ generation and trapping of an ylide from the reaction of an N-acyl aziridine, triphenylphosphine, and an aldehyde in refluxing isopropanol is reported.These compounds can be prepared enantioselectively (> 94.6percent ee) by employing a chiral nonracemic N-acyl aziridine.
