873-76-7Relevant academic research and scientific papers
Hydrogenation of Esters by Manganese Catalysts
Li, Fu,Li, Xiao-Gen,Xiao, Li-Jun,Xie, Jian-Hua,Xu, Yue,Zhou, Qi-Lin
, (2022/01/13)
The hydrogenation of esters catalyzed by a manganese complex of phosphine-aminopyridine ligand was developed. Using this protocol, a variety of (hetero)aromatic and aliphatic carboxylates including biomass-derived esters and lactones were hydrogenated to primary alcohols with 63–98% yields. The manganese catalyst was found to be active for the hydrogenation of methyl benzoate, providing benzyl alcohol with turnover numbers (TON) as high as 45,000. Investigation of catalyst intermediates indicated that the amido manganese complex was the active catalyst species for the reaction. (Figure presented.).
Synthesis, crystal and structural characterization, Hirshfeld surface analysis and DFT calculations of three symmetrical and asymmetrical phosphonium salts
Delaram, Behnaz,Gholizadeh, Mostafa,Makari, Faezeh,Nokhbeh, Seyed Reza,Salimi, Alireza
, (2021/07/01)
Three stable phosphonium salts of 1,4-butanediylebis(triphenylphosphonium) dibromide I, butane-4?bromo-1-(triphenylphosphonium) bromide II and 1,3-propanediylbis(triphenylphosphonium) tetrahydroborate III were synthesized and structurally characterized. Single crystal X-ray diffraction analysis, spectroscopic methods and thermal analysis methods were used for the characterization of titled compounds. Crystallographic data showed that compound I crystallized in the triclinic crystal system with Pī space group and compound II crystallized in the monoclinic crystal system with P21/c space group. The crystal packing structures of I and II were stabilized by various intermolecular interactions, especially of C–H···π contacts. The molecular Hirshfeld surface analysis and 2D fingerprint revealed that the C···H contacts have 24.3% and 18.4% contributions in the crystal packings of compounds I and II, respectively. In addition, the H···Br (28.5%) contact has a considerable contribution to the crystal architecture of compound II. Theoretical studies were performed by DFT method to investigate the structural properties of the titled compounds. The isotopic ratio of boron in tetrahydroborate anion of compound III calculated by 1H NMR spectroscopy. The isotopic ratio for 10B/11B was 19.099 / 80.900%. Reduction of some carbonyl compounds to corresponding alcohols was performed by compound III and the optimum conditions were determined.
A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
supporting information, p. 3565 - 3589 (2021/10/12)
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
A method of synthesis of alcohols
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Paragraph 0067-0072, (2022/01/10)
The present invention belongs to the field of organic synthesis technology, specifically a synthesis method of an alcohol; the present invention is under the catalytic action of tert-butanol lithium, with ester compounds and pinacol borane as raw materials, tetrahydrofuran as a solvent, reacted at 100 ° C for 24h, followed by adding 2mol / LNaOH / MeOH solution, stirred at room temperature overnight to obtain alcohol compounds; the raw materials of the present invention are of extensive sources or easy to prepare, the reaction conditions are relatively mild and do not require a large number of / cumbersome additives, in addition to the tert-butanol lithium catalyst is simple, And the prepared alcohol compounds are of high quality and high separation yield.
Redox-active ligand based Mn(i)-catalyst for hydrosilylative ester reduction
Chakraborty, Soumi,Das, Arpan,Mandal, Swadhin K.
supporting information, p. 12671 - 12674 (2021/12/04)
Herein a Mn(i) catalyst bearing a redox-active phenalenyl (PLY) based ligand is reported for the efficient hydrosilylation of esters to alcohols using the inexpensive silane source polymethylhydrosiloxane (PMHS) under mild conditions. Mechanistic investigations suggest a strong ligand-metal cooperation where a ligand-based single electron transfer (SET) process initiates the reaction through Si-H bond activation.
Hydroboration Reaction and Mechanism of Carboxylic Acids using NaNH2(BH3)2, a Hydroboration Reagent with Reducing Capability between NaBH4and LiAlH4
Wang, Jin,Ju, Ming-Yue,Wang, Xinghua,Ma, Yan-Na,Wei, Donghui,Chen, Xuenian
, p. 5305 - 5316 (2021/04/12)
Hydroboration reactions of carboxylic acids using sodium aminodiboranate (NaNH2[BH3]2, NaADBH) to form primary alcohols were systematically investigated, and the reduction mechanism was elucidated experimentally and computationally. The transfer of hydride ions from B atoms to C atoms, the key step in the mechanism, was theoretically illustrated and supported by experimental results. The intermediates of NH2B2H5, PhCH= CHCOOBH2NH2BH3-, PhCH= CHCH2OBO, and the byproducts of BH4-, NH2BH2, and NH2BH3- were identified and characterized by 11B and 1H NMR. The reducing capacity of NaADBH was found between that of NaBH4 and LiAlH4. We have thus found that NaADBH is a promising reducing agent for hydroboration because of its stability and easy handling. These reactions exhibit excellent yields and good selectivity, therefore providing alternative synthetic approaches for the conversion of carboxylic acids to primary alcohols with a wide range of functional group tolerance.
Oxidation Under Reductive Conditions: From Benzylic Ethers to Acetals with Perfect Atom-Economy by Titanocene(III) Catalysis
Funk, Pierre,Richrath, Ruben B.,Bohle, Fabian,Grimme, Stefan,Gans?uer, Andreas
supporting information, p. 5482 - 5488 (2021/02/03)
Described here is a titanocene-catalyzed reaction for the synthesis of acetals and hemiaminals from benzylic ethers and benzylic amines, respectively, with pendant epoxides. The reaction proceeds by catalysis in single-electron steps. The oxidative addition comprises an epoxide opening. An H-atom transfer, to generate a benzylic radical, serves as a radical translocation step, and an organometallic oxygen rebound as a reductive elimination. The reaction mechanism was studied by high-level dispersion corrected hybrid functional DFT with implicit solvation. The low-energy conformational space was searched by the efficient CREST program. The stereoselectivity was deduced from the lowest lying benzylic radical structures and their conformations are controlled by hyperconjugative interactions and steric interactions between the titanocene catalyst and the aryl groups of the substrate. An interesting mechanistic aspect is that the oxidation of the benzylic center occurs under reducing conditions.
Generation of Oxidoreductases with Dual Alcohol Dehydrogenase and Amine Dehydrogenase Activity
Tseliou, Vasilis,Schilder, Don,Masman, Marcelo F.,Knaus, Tanja,Mutti, Francesco G.
supporting information, p. 3315 - 3325 (2020/12/11)
The l-lysine-?-dehydrogenase (LysEDH) from Geobacillus stearothermophilus naturally catalyzes the oxidative deamination of the ?-amino group of l-lysine. We previously engineered this enzyme to create amine dehydrogenase (AmDH) variants that possess a new hydrophobic cavity in their active site such that aromatic ketones can bind and be converted into α-chiral amines with excellent enantioselectivity. We also recently observed that LysEDH was capable of reducing aromatic aldehydes into primary alcohols. Herein, we harnessed the promiscuous alcohol dehydrogenase (ADH) activity of LysEDH to create new variants that exhibited enhanced catalytic activity for the reduction of substituted benzaldehydes and arylaliphatic aldehydes to primary alcohols. Notably, these novel engineered dehydrogenases also catalyzed the reductive amination of a variety of aldehydes and ketones with excellent enantioselectivity, thus exhibiting a dual AmDH/ADH activity. We envisioned that the catalytic bi-functionality of these enzymes could be applied for the direct conversion of alcohols into amines. As a proof-of-principle, we performed an unprecedented one-pot “hydrogen-borrowing” cascade to convert benzyl alcohol to benzylamine using a single enzyme. Conducting the same biocatalytic cascade in the presence of cofactor recycling enzymes (i.e., NADH-oxidase and formate dehydrogenase) increased the reaction yields. In summary, this work provides the first examples of enzymes showing “alcohol aminase” activity.
Direct use of the solid waste from oxytetracycline fermentation broth to construct Hf-containing catalysts for Meerwein-Ponndorf-Verley reactions
Chen, Yuxin,Yao, Xuefeng,Wang, Xiaolu,Zhang, Xuefeng,Zhou, Huacong,He, Runxia,Liu, Quansheng
, p. 13970 - 13979 (2021/04/22)
The oxytetracycline fermentation broth residue (OFR) is an abundant solid waste in the fermentation industry, which is hazardous but tricky to treat. The resource utilization of the waste OFR is still challenging. In this study, a novel route of using OFR was proposed that OFR was used as the organic ligands to construct a new hafnium based catalyst (Hf-OFR) for Meerwein-Ponndorf-Verley (MPV) reactions of biomass-derived platforms. The acidic groups in OFR were used to coordinate with Hf4+, and the carbon skeleton structures in OFR were used to form the spatial network structures of the Hf-OFR catalyst. The results showed that the synthesized Hf-OFR catalyst could catalyze the MPV reduction of various carbonyl compounds under relatively mild reaction conditions, with high conversions and yields. Besides, the Hf-OFR catalyst could be recycled at least 5 times with excellent stability in activity and structures. The prepared Hf-OFR catalyst possesses the advantages of high efficiency, a simple preparation process, and low cost in ligands. The proposed strategy of constructing catalysts using OFR may provide new routes for both valuable utilization of the OFR solid waste in the fermentation industry and the construction of efficient catalysts for biomass conversion.
Dual utility of a single diphosphine-ruthenium complex: A precursor for new complexes and, a pre-catalyst for transfer-hydrogenation and Oppenauer oxidation
Mukherjee, Aparajita,Bhattacharya, Samaresh
, p. 15617 - 15631 (2021/05/19)
The diphosphine-ruthenium complex, [Ru(dppbz)(CO)2Cl2] (dppbz = 1,2-bis(diphenylphosphino)benzene), where the two carbonyls are mutually cis and the two chlorides are trans, has been found to serve as an efficient precursor for the synthesis of new complexes. In [Ru(dppbz)(CO)2Cl2] one of the two carbonyls undergoes facile displacement by neutral monodentate ligands (L) to afford complexes of the type [Ru(dppbz)(CO)(L)Cl2] (L = acetonitrile, 4-picoline and dimethyl sulfoxide). Both the carbonyls in [Ru(dppbz)(CO)2Cl2] are displaced on reaction with another equivalent of dppbz to afford [Ru(dppbz)2Cl2]. The two carbonyls and the two chlorides in [Ru(dppbz)(CO)2Cl2] could be displaced together by chelating mono-anionic bidentate ligands, viz. anions derived from 8-hydroxyquinoline (Hq) and 2-picolinic acid (Hpic) via loss of a proton, to afford the mixed-tris complexes [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], respectively. The molecular structures of four selected complexes, viz. [Ru(dppbz)(CO)(dmso)Cl2], [Ru(dppbz)2Cl2], [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], have been determined by X-ray crystallography. In dichloromethane solution, all the complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the complexes shows redox responses within 0.71 to -1.24 V vs. SCE. [Ru(dppbz)(CO)2Cl2] has been found to serve as an excellent pre-catalyst for catalytic transfer-hydrogenation and Oppenauer oxidation.
