6628-00-8Relevant academic research and scientific papers
Integrated Electro-Biocatalysis for Amine Alkylation with Alcohols
Pe?afiel, Itziar,Dryfe, Robert A. W.,Turner, Nicholas J.,Greaney, Michael F.
, p. 864 - 867 (2021/01/21)
The integration of electro and bio-catalysis offers new ways of making molecules under very mild, environmentally benign conditions. We show that TEMPO mediated electro-catalytic oxidation of alcohols can be adapted to work in aqueous buffers, with minimal organic co-solvent, enabling integration with biocatalytic reductive amination using the AdRedAm enzyme. The combined process offers a new approach to amine alkylation with native alcohols, a key bond formation in the chemical economy that is currently achieved via precious metal-catalyzed hydrogen-borrowing technologies. The electrobio transformation is effective for primary and secondary alcohols undergoing coupling with allyl, propargyl, benzyl, and cyclopropyl amines, and has been adapted for use with solid-supported AdRedAm for ease of operation.
Identification of Novel Bacterial Members of the Imine Reductase Enzyme Family that Perform Reductive Amination
France, Scott P.,Howard, Roger M.,Steflik, Jeremy,Weise, Nicholas J.,Mangas-Sanchez, Juan,Montgomery, Sarah L.,Crook, Robert,Kumar, Rajesh,Turner, Nicholas J.
, p. 510 - 514 (2018/01/27)
Reductive amination of carbonyl compounds constitutes one of the most efficient ways to rapidly construct chiral and achiral amine frameworks. Imine reductase (IRED) biocatalysts represent a versatile family of enzymes for amine synthesis through NADPH-mediated imine reduction. The reductive aminases (RedAms) are a subfamily of IREDs that were recently shown to catalyze imine formation as well as imine reduction. Herein, a diverse library of novel enzymes were expressed and screened as cell-free lysates for their ability to facilitate reductive amination to expand the known suite of biocatalysts for this transformation and to identify more enzymes with potential industrial applications. A range of ketones and amines were examined, and enzymes were identified that were capable of accepting benzylamine, pyrrolidine, ammonia, and aniline. Amine equivalents as low as 2.5 were employed to afford up to >99 % conversion, and for chiral products, up to >98 % ee could be achieved. Preparative-scale reactions were conducted with low amine equivalents (1.5 or 2.0) of methylamine, allylamine, and pyrrolidine, achieving up to >99 % conversion and 76 % yield.
A Mechanism for Reductive Amination Catalyzed by Fungal Reductive Aminases
Sharma, Mahima,Mangas-Sanchez, Juan,France, Scott P.,Aleku, Godwin A.,Montgomery, Sarah L.,Ramsden, Jeremy I.,Turner, Nicholas J.,Grogan, Gideon
, p. 11534 - 11541 (2018/11/23)
Reductive aminases (RedAms) catalyze the asymmetric reductive amination of ketones with primary amines to give secondary amine products. RedAms have great potential for the synthesis of bioactive chiral amines; however, insights into their mechanism are currently limited. Comparative studies on reductive amination of cyclohexanone with allylamine in the presence of RedAms, imine reductases (IREDs), or NaBH3CN support the distinctive activity of RedAms in catalyzing both imine formation and reduction in the reaction. Structures of AtRedAm from Aspergillus terreus, in complex with NADPH and ketone and amine substrates, along with kinetic analysis of active-site mutants, reveal modes of substrate binding, the basis for the specificity of RedAms for reduction of imines over ketones, and the importance of domain flexibility in bringing the reactive participants together for the reaction. This information is used to propose a mechanism for their action and also to expand the substrate specificity of RedAms using protein engineering.
Photoinduced radical-initiated carboxylative cyclization of allyl amines with carbon dioxide
Wang, Mei-Yan,Cao, Yu,Liu, Xi,Wang, Ning,He, Liang-Nian,Li, Si-Han
supporting information, p. 1240 - 1244 (2017/08/18)
Visible light-promoted CO2 upgrading: a highly efficient and metal-free photochemical method for the carboxylative cyclization of allyl amines with CO2 is reported to prepare perfluoroalkylated oxazolidinones with high efficiency under ambient conditions by using perfluoroalkyl iodides as radical sources.
A biocatalytic cascade for the amination of unfunctionalised cycloalkanes
Tavanti, Michele,Mangas-Sanchez, Juan,Montgomery, Sarah L.,Thompson, Matthew P.,Turner, Nicholas J.
supporting information, p. 9790 - 9793 (2017/12/08)
Here we describe a one-pot, three-enzyme, cascade involving a cytochrome P450 monooxygenase, an alcohol dehydrogenase and a reductive aminase for the synthesis of secondary amines from cycloalkanes. Amine product concentrations of up to 19.6 mM were achieved. The preparative scale amination of cyclohexane was also demonstrated with a space-time yield of 2 g L-1 d-1.
Direct Alkylation of Amines with Primary and Secondary Alcohols through Biocatalytic Hydrogen Borrowing
Montgomery, Sarah L.,Mangas-Sanchez, Juan,Thompson, Matthew P.,Aleku, Godwin A.,Dominguez, Beatriz,Turner, Nicholas J.
supporting information, p. 10491 - 10494 (2017/08/22)
The reductive aminase from Aspergillus oryzae (AspRedAm) was combined with a single alcohol dehydrogenase (either metagenomic ADH-150, an ADH from Sphingobium yanoikuyae (SyADH), or a variant of the ADH from Thermoanaerobacter ethanolicus (TeSADH W110A)) in a redox-neutral cascade for the biocatalytic alkylation of amines using primary and secondary alcohols. Aliphatic and aromatic secondary amines were obtained in up to 99 % conversion, as well as chiral amines directly from the racemic alcohol precursors in up to >97 % ee, releasing water as the only byproduct.
Cycloamidination of Aminoalkenes with Nitriles: Synthesis of Substituted 2-Imidazolines and Tetrahydropyrimidines
Huang, Shujian,Shao, Yinlin,Zhang, Lixin,Zhou, Xigeng
supporting information, p. 14452 - 14456 (2016/01/25)
The first catalytic cycloamidination of aminoalkenes with nitriles has been achieved by using rare-earth complexes. This reaction is equivalent to the desired intramolecular hydroamination of alkenylamidines, and allows a new direct access to substituted 2-imidazolines and tetrahydropyrimidines in high yields under operationally simple reaction conditions. Moreover, the methodology is also efficient for synthesis of symmetric and unsymmetric bridged diimidazolines. Compared with the traditional stepwise-mediated synthetic approaches, the present method avoids the use of additives and harsh reaction conditions, and thus leads to a completely different product distribution. Mechanistic data suggest that the reaction involves the initial NH activation by lanthanide complex followed by nitrile insertion into a Ln-N bond to form an amidinate lanthanide intermediate which undergoes the cyclization.
Chemoselective deprotection of N-allylic amines using DDQ
Kumar, Pradeep,Cherian, Shijo K.,Jain, Ruchi,Show, Krishanu
supporting information, p. 7172 - 7176 (2015/01/09)
A highly chemoselective and simple method for the deprotection of N-allylic amines using DDQ has been developed. The use of DDQ in dichloromethane-water provides a mild and efficient one-step deallylation of a wide variety of orthogonally protected tertiary amine derivatives.
PRODUCTION METHOD FOR 2-ALKENYLAMINE COMPOUND
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Paragraph 0045; 0047, (2014/07/22)
Provided is a method for producing a 2-alkenylamine compound efficiently and at low cost, using a primary or secondary amine compound and a 2-alkenyl compound as the starting materials therefor. The 2-alkenyleamine compound is produced by 2-alkenylating a primary or secondary amine compound, using a specified 2-alkenylating agent and in the presence of a catalyst comprising a complexing agent and a transition metal precursor stabilized by a monovalent anionic five-membered conjugated diene.
Tertiary amines as synthetic equivalents of vinyl cations: Zinc bromide promoted coupling of propargylamines with α-isocyanoacetamides to give 2,4,5-trisubstituted oxazoles initiated by an internal redox process
Odabachian, Yann,Wang, Qian,Zhu, Jieping
, p. 12229 - 12233 (2013/09/23)
Crabee interrupted: Propargylamines 1 react with α-isocyanoacetamides 2 in the presence of zinc bromide to afford vinyl oxazoles 3. The transformation, wherein the propargylamine acts as a vinyl cation synthetic equivalent, involves a domino sequence incorporating a 1,5-hydride shift, intermolecular trapping/cyclization, and a 1,6-elimination (see scheme). Copyright
