22680-44-0Relevant academic research and scientific papers
Fabrication of ω-Transaminase@Metal-Organic Framework Biocomposites for Efficiently Synthesizing Benzylamines and Pyridylmethylamines
Yu, Jinhai,Zong, Weilu,Ding, Yingying,Liu, Junzhong,Chen, Lina,Zhang, Hongjuan,Jiao, Qingcai
, p. 380 - 390 (2021/11/05)
In this study, ten ω-transaminases (ω-TAs) have been investigated to efficiently catalyze the synthesis of twenty-four functionalized benzylamines and pyridylmethylamines. We optimized the reactions, screened suitable amino donors and compared ω-transaminases activities for all aromatic aldehyde substrates. Under the optimized conditions, eighteen aromatic amines have been obtained with 60.4%–96.6% conversions and isolated only via simple extraction and recrystallization with 18.5%–81% yields on a preparative scale. Furthermore, we first immobilized the Bm-STA onto the MOFs via the physical adsorption to overcome the limitation of free enzyme and improve their industrial applications. The obtained Bm-STA/UiO-66-NH2 composites exhibited not only high enzymes loading (80.4 mg g?1) and enzyme activity recovery (95.8%), but also the better reusability, storage stability, pH stability and the tolerance to acetone and DMF.
Transition metal-free catalytic reduction of primary amides using an abnormal NHC based potassium complex: Integrating nucleophilicity with Lewis acidic activation
Bhunia, Mrinal,Sahoo, Sumeet Ranjan,Das, Arpan,Ahmed, Jasimuddin,Sreejyothi,Mandal, Swadhin K.
, p. 1848 - 1854 (2020/03/03)
An abnormal N-heterocyclic carbene (aNHC) based potassium complex was used as a transition metal-free catalyst for reduction of primary amides to corresponding primary amines under ambient conditions. Only 2 mol% loading of the catalyst exhibits a broad substrate scope including aromatic, aliphatic and heterocyclic primary amides with excellent functional group tolerance. This method was applicable for reduction of chiral amides and utilized for the synthesis of pharmaceutically valuable precursors on a gram scale. During mechanistic investigation, several intermediates were isolated and characterized through spectroscopic techniques and one of the catalytic intermediates was characterized through single-crystal XRD. A well-defined catalyst and isolable intermediate along with several stoichiometric experiments, in situ NMR experiments and the DFT study helped us to sketch the mechanistic pathway for this reduction process unravelling the dual role of the catalyst involving nucleophilic activation by aNHC along with Lewis acidic activation by K ions.
Liquid-phase hydrogenation of nitriles to amines facilitated by a co(ii)/zn(0) pair: a ligand-free catalytic protocol
Timelthaler, Daniel,Topf, Christoph
, p. 11604 - 11611 (2019/10/02)
The given report introduces a simple and user-friendly in situ method for the production of catalytically active cobalt particles. The approach circumvents the use of air-and moisture-sensitive reductants as well as the application of anhydrous Co-precursor salts. Accordingly, the described catalytic system is readily assembled under open-flask conditions by simply combining the components in the reaction vessel. Therefore, the arduous charging procedure of the reaction autoclave in a glovebox under an inert gas atmosphere is no longer necessary. In fact, the catalytically active material is obtained upon treatment of readily available Co(OAc)2·4 H2O with benign commercial Zn powder. The catalytic performance of the resultant material was tested in the heterogeneous hydrogenation of nitriles to the corresponding primary amines. Both activity and selectivity of the cobalt catalyst are significantly enhanced if a triflate-based Lewis acid and ammonia is added to the reaction mixture.
Catalytic Reduction of Nitriles by Polymethylhydrosiloxane Using a Phenalenyl-Based Iron(III) Complex
Das, Shyamal,Das, Hari Sankar,Singh, Bhagat,Haridasan, Rahul Koottanil,Das, Arpan,Mandal, Swadhin K.
supporting information, p. 11274 - 11278 (2019/09/10)
The reduction of nitriles to primary amines using an inexpensive silane such as polymethylhydrosiloxane (PMHS) is an industrially important reaction. Herein we report the synthesis of an earth-abundant Fe(III) complex bearing a phenalenyl-based ligand that was characterized by mass spectroscopy, elemental analysis, cyclic voltammetry, and single-crystal X-ray diffraction. The complex showed excellent catalytic activity toward reduction of aromatic, heteroaromatic, aliphatic, and sterically crowded nitriles to produce primary amines using polymethylhydrosiloxane (PMHS).
Primary amides to amines or nitriles: A dual role by a single catalyst
Das, Hari S.,Das, Shyamal,Dey, Kartick,Singh, Bhagat,Haridasan, Rahul,Das, Arpan,Ahmed, Jasimuddin,Mandal, Swadhin K.
supporting information, p. 11868 - 11871 (2019/10/11)
We report a manganese-catalyzed hydrosilylative reduction of various primary amides to amines (25 examples). On simple modification of the reaction conditions such as in the presence of a catalytic amount of secondary amide, the same catalyst can transform the primary amides into intermediate nitrile compounds (16 examples) in excellent yields. This is the first example where such a controlled catalytic transformation of primary amides to amines or nitriles with a single catalyst has been demonstrated.
Synthesis of cobalt nanoparticles by pyrolysis of Vitamin B12: A non-noble-metal catalyst for efficient hydrogenation of nitriles
Ferraccioli, Raffaella,Borovika, Diana,Surkus, Annette-Enrica,Kreyenschulte, Carsten,Topf, Christoph,Beller, Matthias
, p. 499 - 507 (2018/02/07)
A facile preparation of vitamin B12-derived carbonaceous cobalt particles supported on ceria is reported. The resulting composite material is obtained upon wet impregnation of ceria with natural cyanocobalamin and consecutive pyrolysis under inert conditions. The novel catalyst shows good to excellent performance in the industrially relevant heterogeneous hydrogenation of nitriles to the corresponding primary amines.
Exhaustive Chemoselective Reduction of Nitriles by Catalytic Hydrosilylation Involving Cooperative Si-H Bond Activation
Wübbolt, Simon,Oestreich, Martin
supporting information, p. 2411 - 2414 (2017/10/03)
A chemoselective method for the catalytic hydrosilylation of nitriles to either the imine or amine oxidation level is reported. The chemoselectivity is controlled by the hydrosilane used. The usefulness of the nitrile-to-amine reduction is demonstrated for a diverse set of aromatic and aliphatic nitriles, and the amines are easily isolated after hydrolysis as their hydrochloride salts. This exhaustive nitrile reduction proceeds at room temperature.
A method for the production of primary amines
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Paragraph 0212; 0213, (2016/10/09)
The invention relates to the field of chemical industry and particularly relates to a method for preparing primary amine by using the raw materials including halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) and ammonia water (or formamide). The method comprises the following three steps: (1) imidization: 3,4-diarylfuran-2,5-diketone (I) reacts with ammonia (or formamide) and the like to obtain 3,4-diaryl-1H-pyrrole-2,5-diketone (II); (2) N-hydrocarbylation: 3,4-diaryl-1H-pyrrole-2,5-diketone (II) generates an N-hydrocarbylation reaction with halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) in the presence of alkali to obtain N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III); and (3) hydrolysis: N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III) is subjected to alkali hydrolysis to obtain primary amine and the generated 2,3-diaryl maleate is subjected to acid treatment and automatic ring closing to form 3,4-diaryl furan-2,5-diketone (I) which is subjected to imidization and directly applied to the N-hydrocarbylation reaction. The method provided by the invention has the characteristics that the 3,4-diaryl furan-2,5-diketone can be circularly used at a high recovery rate, the molar ratio of the raw materials is low, and the yield of the product primary amine is high.
Stable and Inert Cobalt Catalysts for Highly Selective and Practical Hydrogenation of C≡N and C=O Bonds
Chen, Feng,Topf, Christoph,Radnik, J?rg,Kreyenschulte, Carsten,Lund, Henrik,Schneider, Matthias,Surkus, Annette-Enrica,He, Lin,Junge, Kathrin,Beller, Matthias
supporting information, p. 8781 - 8788 (2016/08/02)
Novel heterogeneous cobalt-based catalysts have been prepared by pyrolysis of cobalt complexes with nitrogen ligands on different inorganic supports. The activity and selectivity of the resulting materials in the hydrogenation of nitriles and carbonyl compounds is strongly influenced by the modification of the support and the nitrogen-containing ligand. The optimal catalyst system ([Co(OAc)2/Phenα-Al2O3]-800 = Cat. E) allows for efficient reduction of both aromatic and aliphatic nitriles including industrially relevant dinitriles to primary amines under mild conditions. The generality and practicability of this system is further demonstrated in the hydrogenation of diverse aliphatic, aromatic, and heterocyclic ketones as well as aldehydes, which are readily reduced to the corresponding alcohols.
Selective Catalytic Hydrogenations of Nitriles, Ketones, and Aldehydes by Well-Defined Manganese Pincer Complexes
Elangovan, Saravanakumar,Topf, Christoph,Fischer, Steffen,Jiao, Haijun,Spannenberg, Anke,Baumann, Wolfgang,Ludwig, Ralf,Junge, Kathrin,Beller, Matthias
supporting information, p. 8809 - 8814 (2016/07/29)
Hydrogenations constitute fundamental processes in organic chemistry and allow for atom-efficient and clean functional group transformations. In fact, the selective reduction of nitriles, ketones, and aldehydes with molecular hydrogen permits access to a green synthesis of valuable amines and alcohols. Despite more than a century of developments in homogeneous and heterogeneous catalysis, efforts toward the creation of new useful and broadly applicable catalyst systems are ongoing. Recently, Earth-abundant metals have attracted significant interest in this area. In the present study, we describe for the first time specific molecular-defined manganese complexes that allow for the hydrogenation of various polar functional groups. Under optimal conditions, we achieve good functional group tolerance, and industrially important substrates, e.g., for the flavor and fragrance industry, are selectively reduced.
