98180-43-9Relevant articles and documents
Reductions of carboxylic acids and their derivatives using samarium diiodide-acid system
Kamochi,Kudo
, p. 4301 - 4312 (1992)
Carboxylic acid was converted to alcohol in a facile-rapid reduction using samarium diiodide in protic solvent under a basic or acidic medium at room temperature in high yield. A similar reaction of ester and anhydride reduced to the corresponding alcohol as the major products and nitrile afforded amine. Amide was rapidly reduced under a basic medium to afford alcohol, but the reduction with samarium diiodide-acid system of amide gave aldehyde in quantitative yield.
Switching Selectivity in Copper-Catalyzed Transfer Hydrogenation of Nitriles to Primary Amine-Boranes and Secondary Amines under Mild Conditions
Song, Hao,Xiao, Yao,Zhang, Zhuohua,Xiong, Wanjin,Wang, Ren,Guo, Liangcheng,Zhou, Taigang
, p. 790 - 800 (2022/01/11)
A simple and efficient copper-catalyzed selective transfer hydrogenation of nitriles to primary amine-boranes and secondary amines with an oxazaborolidine-BH3 complex is reported. The selectivity control was achieved under mild conditions by switching the solvent and the copper catalysts. More than 30 primary amine-boranes and 40 secondary amines were synthesized via this strategy in high selectivity and yields of up to 95%. The strategy was applied to the synthesis of 15N labeled in 89% yield.
Aluminum Metal-Organic Framework-Ligated Single-Site Nickel(II)-Hydride for Heterogeneous Chemoselective Catalysis
Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Dwivedi, Ashutosh,Manna, Kuntal
, p. 3943 - 3957 (2021/04/12)
The development of chemoselective and heterogeneous earth-abundant metal catalysts is essential for environmentally friendly chemical synthesis. We report a highly efficient, chemoselective, and reusable single-site nickel(II) hydride catalyst based on robust and porous aluminum metal-organic frameworks (MOFs) (DUT-5) for hydrogenation of nitro and nitrile compounds to the corresponding amines and hydrogenolysis of aryl ethers under mild conditions. The nickel-hydride catalyst was prepared by the metalation of aluminum hydroxide secondary building units (SBUs) of DUT-5 having the formula of Al(μ2-OH)(bpdc) (bpdc = 4,4′-biphenyldicarboxylate) with NiBr2 followed by a reaction with NaEt3BH. DUT-5-NiH has a broad substrate scope with excellent functional group tolerance in the hydrogenation of aromatic and aliphatic nitro and nitrile compounds under 1 bar H2 and could be recycled and reused at least 10 times. By changing the reaction conditions of the hydrogenation of nitriles, symmetric or unsymmetric secondary amines were also afforded selectively. The experimental and computational studies suggested reversible nitrile coordination to nickel followed by 1,2-insertion of coordinated nitrile into the nickel-hydride bond occurring in the turnover-limiting step. In addition, DUT-5-NiH is also an active catalyst for chemoselective hydrogenolysis of carbon-oxygen bonds in aryl ethers to afford hydrocarbons under atmospheric hydrogen in the absence of any base, which is important for the generation of fuels from biomass. This work highlights the potential of MOF-based single-site earth-abundant metal catalysts for practical and eco-friendly production of chemical feedstocks and biofuels.
Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia-Borane
Sarkar, Koushik,Das, Kuhali,Kundu, Abhishek,Adhikari, Debashis,Maji, Biplab
, p. 2786 - 2794 (2021/03/03)
Herein we report the synthesis of primary and secondary amines by nitrile hydrogenation, employing a borrowing hydrogenation strategy. A class of phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia-borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled by changing the catalyst structure and the polarity of the reaction medium. The significant advantage of this method is that the protocol operates without externally added base or other additives as well as obviates the use of high-pressure dihydrogen gas required for other nitrile hydrogenation reactions. Utilizing this method, a wide variety of primary and symmetric and asymmetric secondary amines were synthesized in high yields. A mechanistic study involving kinetic experiments and high-level DFT computations revealed that both outer-sphere dehydrogenation and inner-sphere hydrogenation were predominantly operative in the catalytic cycle.
Chemoselective transfer hydrogenation of nitriles to secondary amines with nickel(II) catalysts
Vermaak, Vincent,Vosloo, Hermanus C.M.,Swarts, Andrew J.
, (2021/07/25)
Herein we report the selective transfer hydrogenation (TH) of nitriles to secondary (2°) amines with simple Ni(II)-catalysts using ammonia borane (AB) as a source of hydrogen (H2). A bis(pyrazolylmethyl)pyridine (L1) or ethylenediamine (L4) ligated Ni(II) pre-catalyst, created in situ, could hydrogenate several aromatic- and aliphatic nitriles in full conversions and isolated yields of up to 88% under ambient temperature and in very short reaction times. Deuterium labelling experiments illustrated the incorporation of a proton on the nitrogen and hydride on the α-carbon of dibenzylamine. Using α-picoline borane, containing no dissociable protons, assisted with the postulation of a two-step TH mechanism of benzonitrile. AB was subjected to dehydrogenation and it was observed that a maximum of 2.96 equivalents of H2 gas could be generated from NiCl2?6H2O/L1.
Method for synthesizing dibenzylamine compound by selective hydrogenation of photocatalytic benzonitrile compound
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Paragraph 0032-0035, (2021/09/29)
The invention belongs to the technical field of selective catalytic hydrogenation, and particularly relates to a method for synthesizing a dibenzylamine compound through selective hydrogenation of a photocatalytic benzonitrile compound, wherein the photocatalyst is prepared from silicon carbide with high specific surface area (specific surface area 20 - 100m). 2 Metal Platinum as a carrier load mass fraction 0.1-20%, the metal nanoparticles being less than 200 nanometers ?. g. After mixing the benzonitrile compound and the solvent at 0.01 - 0.6 mass ratio, the catalyst was added, and the hydrogen pressure was maintained between 0.1 mpa - 2 mpa under hydrogen atmosphere and the reaction was stirred while maintaining the temperature of the reaction system was 10 - 100 °C and the strength was 0.01 - 5W/cm. 2 Under the light intensity of the reaction 0.5 - 12h, the target product can be obtained. The method has the most remarkable characteristics of being capable of effectively utilizing light to promote reaction and high in reaction rate.
Platinum Nanoparticles Uniformly Dispersed on Covalent Organic Framework Supports for Selective Synthesis of Secondary Amines
Li, Xinjun,Liu, Jianguo,Ma, Longlong,Tang, Long,Wang, Chenguang,Wang, Nan
, (2022/01/22)
Covalent organic frameworks (COFs) with pore structures are talented supports for active components. In this report, COF has been rationally fabricated and served as host for growing uniformly dispersed platinum nanoparticles with a narrow size distribution (2 nm). The obtained hybrid Pt/COF exhibits high catalytic activity in the reductive amination of benzaldehyde towards secondary amines with a yield of 96 % and good recyclability. The preferable selectivity towards secondary amines could be attributed to synergistic effects of active platinum nanoparticles and COF, in which metallic Pt nanoparticles were uniformly dispersed with a positively charged surface. This work will open an avenue towards controlling the interaction between active metals and support as well as rational design of catalysts for demanding transformations for fine agrochemicals intermediates.
Application of nano-carbon supported monatomic palladium-based catalyst in catalytic hydrogenation of nitrile compound to prepare secondary amine
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Paragraph 0042; 0043; 0050; 0051, (2020/03/06)
The invention discloses application of a nano-carbon supported monatomic palladium-based catalyst in catalytic hydrogenation of a nitrile compound to prepare a secondary amine and belongs to the technical field of catalysts with application of catalytic hydrogenation of liquid-phase nitrile compounds. By adopting the monatomically dispersed palladium-based catalyst, a corresponding secondary aminecompound is generated with high selectivity under a mild condition, and the catalysis reaction conditions are that the reaction temperature is 45-90 DEG C and ammonia borane is adopted as a hydrogensource. In the catalyst disclosed by the invention, metals exist in a monatomic dispersion state, so that the utilization efficiency of the metals can be effectively improved, and the activity and theselectivity of the nitrile compound can be remarkably improved. In addition, the monatomically dispersed catalyst is convenient to prepare and low in cost, and has very good application prospects incatalytic hydrogenation of the nitrile compound to prepare the secondary amine.
Selective Synthesis of Symmetrical Secondary Amines from Nitriles with a Pt?CuFe/Fe3O4 Catalyst and Ammonia Borane as Hydrogen Donor
Ai, Yongjian,Guo, Rongxiu,He, GuangQi,Hu, Ze-nan,Liang, Qionglin,Liu, Lei,Niu, Dun,Sun, Hong-bin,Tian, Haimeng,Zhang, Xinyue
, p. 1783 - 1788 (2020/09/02)
Hydrogenation of nitriles is an efficient and environmentally friendly route to synthesize symmetrical secondary amines, but it usually produces a mixture of amines, imines, and hydrogenolysis by-products. Herein we report a magnetic quaternary-component Pt?CuFe/Fe3O4 nanocatalyst system for the selective synthesis of symmetrical secondary amines with ammonia borane as hydrogen donor. The catalyst with a low Pt loading (0.456 wt%) is the source of the activity, and the d-band electron transfer from Cu to Fe enhances the selectivity. This synergistic effect results in the transformation of benzonitrile to dibenzylamine with excellent conversion (up to 99 %) and nearly quantitative selectivity (up to 96 %) under mild reaction conditions, nevertheless, the reaction TOF is as high as up to 1409.9 h?1. A variety of nitriles are suitable for the synthesis of symmetrical secondary amines. More importantly, unwanted hydrogenolysis byproducts, especially toluene, is not detected at all. In addition, the catalyst is magnetically recoverable, and it can be reused up to five times.
Selective Synthesis of Secondary Amines from Nitriles by a User-Friendly Cobalt Catalyst
Sharma, Dipesh M.,Punji, Benudhar
supporting information, p. 3930 - 3936 (2019/07/12)
Selective hydrogenation/reductive amination of nitriles to secondary amines catalyzed by an inexpensive and user-friendly cobalt complex, (Xantphos)CoCl2, is reported. The use of (Xantphos)CoCl2 and ammonia borane (NH3?BH3) combination affords the selective reduction of nitriles to symmetrical secondary amines, whereas the employment of (Xantphos)CoCl2 and dimethylamine borane (Me2NH?BH3) along with external amines produce unsymmetrical secondary amines and tertiary amines. The general applicability of this methodology is demonstrated by the synthesis of 43 symmetrical and unsymmetrical secondary and tertiary amines bearing diverse functionalities. (Figure presented.).
