1475-13-4Relevant academic research and scientific papers
1,3,4-Oxadiazole-functionalizedα-amino-phosphonates as ligands for the ruthenium-catalyzed reduction of ketones
Hkiri, Shaima,Gourlaouen, Christophe,Touil, Soufiane,Samarat, Ali,Sémeril, David
, p. 11327 - 11335 (2021)
Threeα-aminophosphonates, namely diethyl[(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-trifluoromethylphenyl) methyl]phosphonate (3a), diethyl[(5-phenyl-1,3,4-oxadiazol-2-ylamino)(2-methoxyphenyl)methyl]phosphonate (3b) and diethyl[(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-nitrophenyl)methyl]phosphonate (3c), were synthetizedviathe Pudovik-type reaction between diethyl phosphite and imines, obtained from 5-phenyl-1,2,4-oxadiazol-2-amine and aromatic aldehydes, under microwave irradiation. Compounds3a-cunderwent complexation with a ruthenium(ii) precursor, selectively at the more basic nitrogen atom of the oxadiazole ring, leading to the corresponding ruthenium complexes4a-cof the formula [RuCl2(L)(p-cymene)] (L= α-aminophosphonates3a-c). Complexes4a-cproved to be efficient catalysts for the transfer hydrogenation of ketones to alcohols. All new compounds were fully characterised by elemental analysis, infrared, mass and NMR spectroscopy. An X-ray structure of the α-aminophosphonate3bwas obtained and revealed the presence, in the solid state, of an infinite chain of3bunits supramolecularly interlinked. Two X-ray diffraction studies carried out on ruthenium complexes confirm the specific coordination of the electron-enricher nitrogen atom of the oxadiazole ring.
Pincerlike molybdenum complex and preparation method thereof, catalytic composition and application thereof, and alcohol preparation method
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Paragraph 0125-0130, (2021/08/11)
The invention discloses a clamp-type molybdenum complex, a preparation method, a corresponding catalyst composition and application. The method comprises the steps: obtaining 9 molybdenum complexes with different structures through coordination reaction of 2-(substituent ethyl)-(5, 6, 7, 8-tetrahydroquinolyl) amine and a corresponding carbonyl molybdenum metal precursor; and catalyzing a ketone compound transfer hydrogenation reaction through a molybdenum complex to generate 40 alcohol compounds. The preparation method of the molybdenum complex is simple, high in yield and good in stability. For a transfer hydrogenation reaction of ketone, the molybdenum-based catalytic system has high catalytic activity and small molybdenum loading capacity, is used for production of aromatic and aliphatic alcohols, and has the advantages of simple method, small environmental pollution and high yield.
Ruthenium complexes of phosphine-amide based ligands as efficient catalysts for transfer hydrogenation reactions
Yadav, Samanta,Vijayan, Paranthaman,Yadav, Sunil,Gupta, Rajeev
, p. 3269 - 3279 (2021/03/16)
This work presents three mononuclear Ru(ii) complexes of tridentate phosphine-carboxamide based ligands providing a NNP coordination environment. The octahedral Ru(ii) ion shows additional coordination with co-ligands; CO, Cl and CH3OH. All three Ru(ii) complexes were thoroughly characterized including their crystal structures. These Ru(ii) complexes were utilized as catalysts for the transfer hydrogenation of assorted carbonyl compounds, including some challenging biologically relevant substrates, using isopropanol as the hydrogen source. The binding studies illustrated the coordination of the isopropoxide ion by replacing a Ru-ligated chloride ion followed by the generation of the Ru-H intermediate that was isolated and characterized and was found to be involved in the catalysis.
Transfer Hydrogenation of Ketones and Imines with Methanol under Base-Free Conditions Catalyzed by an Anionic Metal-Ligand Bifunctional Iridium Catalyst
Han, Xingyou,Li, Feng,Liu, Peng,Wang, Rongzhou,Xu, Jing
, p. 2242 - 2249 (2020/03/13)
An anionic iridium complex [Cp*Ir(2,2′-bpyO)(OH)][Na] was found to be a general and highly efficient catalyst for transfer hydrogenation of ketones and imines with methanol under base-free conditions. Readily reducible or labile substituents, such as nitro, cyano, and ester groups, were tolerated under present reaction conditions. Notably, this study exhibits the unique potential of anionic metal-ligand bifunctional iridium catalysts for transfer hydrogenation with methanol as a hydrogen source.
Aza-crown compounds synthesised by the self-condensation of 2-amino-benzyl alcohol over a pincer ruthenium catalyst and applied in the transfer hydrogenation of ketones
Zhang, Shanshan,Wang, Zheng,Cao, Qianrong,Yue, Erlin,Liu, Qingbin,Ma, Yanping,Liang, Tongling,Sun, Wen-Hua
supporting information, p. 15821 - 15827 (2020/11/24)
A well-defined PNN-Ru catalyst was revisited to self-condense 2-aminobenzyl alcohol in forming a series of novel aza-crown compounds [aza-12-crown-3 (1), aza-16-crown-4 (2) and aza-20-crown-5 (3)]. All aza-crown compounds are separated and determined by NMR, IR, and ESI-MS spectroscopy as well as X-ray crystallography, indicating the saddle structure of 1 and the twisted 1,3-alternate conformation structure of 3. These aza-crown compounds have been explored to study ferric initiation of transfer hydrogenation (TH) of ketones into their corresponding secondary alcohols in the presence of 2-propanol with a basic t-BuOK solution, achieving a high conversion (up to 95%) by a ferric complex with 2 in a low loading (0.05 mol%). This journal is
Synthetic Versatility of Lipases: Application for Si-O Bond Formation and Cleavage
Brondani, Patrícia Bulegon,Mittersteiner, Mateus,Voigt, Morgana Aline,Klinkowski, Bruna Heloisa,Riva Scharf, Dilamara,De Jesus, Paulo Cesar
, p. 477 - 485 (2019/01/10)
Several commercially available lipases were examined in a study on O-Si bond formation and cleavage applying silicon-based protecting groups and alcohols or the corresponding silyl ethers. With regard to deprotection, from silyl ether to the corresponding alcohol, only the solvent and the lipase were necessary. The influence of the protecting group, the lipase source, and the substituent was investigated to optimize the results. The TMS moiety could be removed in 24 hours of reaction at room temperature in aqueous systems (conv. up to 99%, depending on the substrate and lipase). The reverse reactions, that is, with the protection of the alcohols, were carried out in hexane using different silyl chlorides. The TMS, TES, and TBS moieties were successfully inserted in the primary and secondary alcohols without the need for dry conditions or an inert atmosphere, presenting conversions of up to 99%, depending on the substrate.
Method for synthesizing pesticide intermediate 2,4-dichloroacetophenone by recycling epoxypropane coproduct
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Paragraph 0038; 0039, (2019/01/21)
The invention belongs to the technical field of organic chemical industry, relates to a preparation method of a halogen-containing aromatic ketone organic compound 2,4-dichloroacetophenone, and concretely relates to a method for synthesizing an important pesticide intermediate 2,4-dichloroacetophenone, for an efficient bactericide propiconazole, a pesticide chlorfenvinphos and a herbicide difenzoquat, from alpha-methylbenzyl alcohol, co-produced through an ethylbenzene co-oxidation technology (PO/SM technology), by halogenation, chlorination, alkaline hydrolysis and oxidation reactions. The total yield is 85% or above, and the purity of the product is 99.7% or above. The method has the advantages of clean process, low raw material cost, high product purity, and easiness in industrialization realization.
A comparative study on asymmetric reduction of ketones using the growing and resting cells of marine-derived fungi
Liu, Hui,Chen, Bi-Shuang,Ribeiro de Souza, Fayene Zeferino,Liu, Lan
, (2018/02/28)
Whole-cell biocatalysts offer a highly enantioselective, minimally polluting route to optically active alcohols. Currently, most of the whole-cell catalytic performance involves resting cells rather than growing cell biotransformation, which is one-step process that benefits from the simultaneous growth and biotransformation, eliminating the need for catalysts preparation. In this paper, asymmetric reduction of 14 aromatic ketones to the corresponding enantiomerically pure alcohols was successfully conducted using the growing and resting cells of marine-derived fungi under optimized conditions. Good yields and excellent enantioselectivities were achieved with both methods. Although substrate inhibition might be a limiting factor for growing cell biotransformation, the selected strain can still completely convert 10-mM substrates into the desired products. The resting cell biotransformation showed a capacity to be recycled nine times without a significant decrease in the activity. This is the first study to perform asymmetric reduction of ketones by one-step growing cell biotransformation.
An air and moisture tolerant iminotrihydroquinoline-ruthenium(ii) catalyst for the transfer hydrogenation of ketones
Li, Jiaoyan,Ma, Yingmiao,Wang, Zheng,Liu, Qingbin,Solan, Gregory A.,Ma, Yanping,Sun, Wen-Hua
, p. 8738 - 8745 (2018/07/13)
Reaction of 8-amino-5,6,7,8-tetrahydroquinoline with RuCl2(PPh3)3 at room temperature affords the ruthenium(ii) chelate (8-NH2-C9H10N)RuCl2(PPh3)2 (E), in which the two triphenylphosphine ligands are disposed mutually cis. By contrast, when the reaction is performed at reflux ligand oxidation/dehydrogenation occurs along with cis-trans reorganization of the triphenylphosphines to form the 8-imino-5,6,7-trihydroquinoline-ruthenium(ii) complex, (8-NH-C9H9N)RuCl2(PPh3)2 (F). Complex F can also be obtained in higher yield by heating a solution of E alone to reflux. Comparison of their molecular structures highlights the superior binding properties of the bidentate imine ligand in F over its amine-containing counterpart in E. Both complexes are highly effective in the transfer hydrogenation of a wide range of alkyl-, aryl- and cycloalkyl-containing ketones affording their corresponding secondary alcohols with loadings of as low as 0.1 mol%. Significantly, F can deliver excellent conversions even in bench quality 2-propanol in reaction vessels open to the air, whereas the catalytic efficiency of E is diminished by the presence of air but only operates efficiently under inert conditions.
Design, synthesis and structure-based optimization of novel isoxazole-containing benzamide derivatives as FtsZ modulators
Bi, Fangchao,Song, Di,Zhang, Nan,Liu, Zhiyang,Gu, Xinjie,Hu, Chaoyu,Cai, Xiaokang,Venter, Henrietta,Ma, Shutao
, p. 90 - 103 (2018/10/04)
Antibiotic resistance among clinically significant bacterial pathogens is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. Utilizing computational docking method and structure-based optimization strategy, we rationally designed and synthesized two series of isoxazol-3-yl- and isoxazol-5-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compounds B14 and B16 that possessed the isoxazol-5-yl group showed strong antibacterial activity against various testing strains, including methicillin-resistant Staphylococcus aureus and penicillin-resistant S. aureus. Further molecular biological studies and docking analyses proved that the compound functioned as an effective inhibitor to alter the dynamics of FtsZ self-polymerization via a stimulatory mechanism, which finally terminated the cell division and caused cell death. Taken together, these results could suggest a promising chemotype for development of new FtsZ-targeting bactericidal agent.
