42365-52-6Relevant academic research and scientific papers
Green method for catalyzing reduction reaction of aliphatic nitro derivative
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Paragraph 0005-0006; 0065-0068, (2021/07/31)
The invention relates to a green method for catalyzing reduction reaction of aliphatic nitro derivatives. According to the method, non-transition metal compounds, namely triethyl boron and potassium tert-butoxide, are used as a catalytic system for the first time, an aliphatic nitro derivative and pinacolborane which is low in price and easy to obtain are catalyzed to be subjected to a reduction reaction under mild conditions, and an aliphatic amine hydrochloride product is synthesized after acidification with a hydrochloric acid aqueous solution. Compared with a traditional method, the method generally has the advantages that the catalyst is cheap and easy to obtain, operation is convenient, and reaction is safe. The selective reduction reaction of the aliphatic nitro derivative catalyzed by the non-transition metal catalyst and pinacol borane is realized for the first time, and the aliphatic amine hydrochloride product is synthesized through acidification treatment of the hydrochloric acid aqueous solution, so that a practical new reaction strategy is provided for laboratory preparation or industrial production.
Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 1618 - 1629 (2021/01/25)
Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
Benzimidazole fragment containing Mn-complex catalyzed hydrosilylation of ketones and nitriles
Ganguli, Kasturi,Mandal, Adarsha,Sarkar, Bidisha,Kundu, Sabuj
, (2020/08/13)
The synthesis of a new bidentate (NN)–Mn(I) complex is reported and its catalytic activity towards the reduction of ketones and nitriles is studied. On comparing the reactivity of various other Mn(I) complexes supported by benzimidazole ligand, it was observed that the Mn(I) complexes bearing 6-methylpyridine and benzimidazole fragments exhibited the highest catalytic activity towards monohydrosilylation of ketones and dihydrosilylation of nitriles. Using this protocol, a wide range of ketones were selectively reduced to the corresponding silyl ethers. In case of unsaturated ketones, the chemoselective reduction of carbonyl group over olefinic bonds was observed. Additionally, selective dihydrosilylation of several nitriles were also achieved using this complex. Mechanistic investigations with radical scavengers suggested the involvement of radical species during the catalytic reaction. Stoichiometric reaction of the Mn(I) complex with phenylsilane revealed the formation of a new Mn(I) complex.
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.
Synthesis of Molybdenum Pincer Complexes and Their Application in the Catalytic Hydrogenation of Nitriles
Leischner, Thomas,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
, p. 4543 - 4549 (2020/07/13)
A series of molybdenum(0), (I) and (II) complexes ligated by different PNP and NNN pincer ligands were synthesized and structurally characterized. Along with previously described Mo?PNP complexes Mo-1 and Mo-2, all prepared compounds were tested in the catalytic hydrogenation of aromatic nitriles to primary amines. Among the applied catalysts, Mo-1 is particularly well suited for the hydrogenation of electron-rich benzonitriles. Additionally, two aliphatic nitriles were transformed into the desired products in 80 and 86 percent, respectively. Moreover, catalytic intermediate Mo-1a was isolated and its role in the catalytic cycle was subsequently 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.
Cobalt-Catalyzed and Lewis Acid-Assisted Nitrile Hydrogenation to Primary Amines: A Combined Effort
Tokmic, Kenan,Jackson, Bailey J.,Salazar, Andrea,Woods, Toby J.,Fout, Alison R.
supporting information, p. 13554 - 13561 (2017/10/05)
The selective hydrogenation of nitriles to primary amines using a bench-stable cobalt precatalyst under 4 atm of H2 is reported herein. The catalyst precursor was reduced in situ using NaHBEt3, and the resulting Lewis acid formed, BEt3, was found to be integral to the observed catalysis. Mechanistic insights gleaned from para-hydrogen induced polarization (PHIP) transfer NMR studies revealed that the pairwise hydrogenation of nitriles proceeded through a Co(I/III) redox process.
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.
Hydrogenation of Aliphatic and Aromatic Nitriles Using a Defined Ruthenium PNP Pincer Catalyst
Neumann, Jacob,Bornschein, Christoph,Jiao, Haijun,Junge, Kathrin,Beller, Matthias
, p. 5944 - 5948 (2015/09/22)
Selective catalytic reductions of nitriles are presented using the commercially available Ru-Macho-BH complex. A variety of aliphatic, aromatic and (hetero)cyclic nitriles including industrially important adipodinitrile are hydrogenated to the corresponding primary amines. Modelling suggests the reaction follows an outer sphere hydrogenation mechanism. An efficient and selective catalytic reduction of nitriles is presented using the commercially available Ru-Macho-BH complex. A variety of aliphatic, aromatic and (hetero)cyclic nitriles including the industrially important adipodinitrile are hydrogenated to the corresponding primary amines. The reaction follows an outer-sphere mechanism.
