120121-01-9Relevant articles and documents
A homochiral microporous hydrogen-bonded organic framework for highly enantioselective separation of secondary alcohols
Li, Peng,He, Yabing,Guang, Jie,Weng, Linghong,Zhao, John Cong-Gui,Xiang, Shengchang,Chen, Banglin
, p. 547 - 549 (2014)
A homochiral microporous hydrogen-bonded organic framework (HOF-2) based on a BINOL derivative has been synthesized and structurally characterized to be a uninodal 6-connected {3355667} network. This new HOF exhibits not only a permanent porosity with the BET of 237.6 m 2 g-1 but also, more importantly, a highly enantioselective separation of chiral secondary alcohols with ee value up to 92% for 1-phenylethanol.
Iron(II) complexes for the efficient catalytic asymmetric transfer hydrogenation of ketones
Meyer, Nils,Lough, Alan J.,Morris, Robert H.
, p. 5605 - 5610 (2009)
Iron(II) carbonyl compounds of the type trans-[Fe(NCMe)(CO)(P-N-N-P)] [BF4]2 bearing the ethylenediamine-derived diiminodiphosphine ligands (R,R)- or (5,5)-1,2-diphenyl-1,2-diaminoethane were synthesized and characterized, including by their crystal structures. The new complexes are suitable precatalysts for the transfer hydrogenation of ketones at room temperature, giving turnover frequencies of up to 2600 h-1 with low catalyst loadings (0.025-0.17%). Screening experiments showed that the precatalysts are able to produce alcohols from a wide range of simple ketones. For sterically demanding prochiral ketones, excellent enantioselectivities were obtained (up to 96% ee).
Novel chiral tetraaza ligands: synthesis and application in asymmetric transfer hydrogenation of ketones
Shen, Wei-Yi,Zhang, Hui,Zhang, Hua-Lin,Gao, Jing-Xing
, p. 729 - 733 (2007)
Novel chiral tetraaza ligands, N1,N2-bis(2-(piperidin-1-yl)benzylidene)cyclohexane-1,2-diamine 1 and N1,N2-bis(2-(piperidin-1-yl)benzyl)cyclohexane-1,2-diamine 2, have been synthesized and fully characterized by
Dimeric Ruthenium(II)-NNN Complex Catalysts Bearing a Pyrazolyl-Pyridylamino-Pyridine Ligand for Transfer Hydrogenation of Ketones and Acceptorless Dehydrogenation of Alcohols
Wang, Qingfu,Chai, Huining,Yu, Zhengkun
, p. 3638 - 3644 (2017)
Dimeric pincer-type ruthenium(II)-NNN complexes bearing an unsymmetrical pyrazolyl-pyridylamino-pyridine ligand were prepared and characterized by NMR, elemental analysis, and X-ray single crystal structural determination. These complexes exhibited very high catalytic activity for both transfer hydrogenation of ketones and acceptorless dehydrogenation of secondary alcohols, achieving TOF values up to 1.9 × 106 h-1 in the transfer hydrogenation of ketones. The high catalytic activity of the Ru(II) complex catalysts is attributed to the presence of the unprotected NH functionality in the ligand and hemilabile unsymmetrical coordination environment around the central metal atoms in the complex.
-
Emerson,Lucas
, p. 1180 (1948)
-
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
, p. 15821 - 15827 (2020)
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
Samarium-induced convenient reductive dimerization of aromatic ketones in aqueous methanol: A mechanistic approach
Banik, Bimal K.,Banik, Indrani,Aounallah, Nacer,Castillo, Mark
, p. 7065 - 7068 (2005)
Samarium metal has been used for the reductive dimerization of aromatic ketones in the presence of additives; the most probable mechanism has been advanced to explain the diastereoselectivity of this dimerization reaction.
Applications of ruthenium hydride borohydride complexes containing phosphinite and diamine ligands to asymmetric catalytic reactions
Guo, Rongwei,Chen, Xuanhua,Elpelt, Christian,Song, Datong,Morris, Robert H.
, p. 1757 - 1759 (2005)
(Chemical Equation Presented) A series of novel trans-ruthenium hydride borohydride complexes with chiral phosphinite and diamine ligands were synthesized. They can be used in the asymmetric transfer hydrogenation of aryl ketones, including base-sensitive
Efficient asymmetric transfer hydrogenation of ketones catalyzed by an iron complex containing a P-N-N-P tetradentate ligand formed by template synthesis
Mikhailine, Alexandre,Lough, Alan J.,Morris, Robert H.
, p. 1394 - 1395 (2009)
-
Enantioselective reduction of acetophenone analogues using carrot and celeriac enzymes system
Liu, Xiang,Pan, Zheng Guang,Xu, Jian He,Li, He Xing
, p. 305 - 308 (2010)
The enantioselective reduction of acetophenone analogues catalyzed by carrot and celeriac was performed in moderate conversions and excellent enantiomeric excesses. The steric factors and electronic effects of the substituents at the aromatic ring were found to significantly affect the efficiency of the enantioselective reduction of acetophenone analogues, while they had a little effect on the enantioselectivity of acetophenone analogues reduction. It was also found that the conversions of acetophenone analogues reduction at 33 °C by means of both biocatalysts were three times as great as those at room temperature.
Reverse micellar aggregates: Effect on ketone reduction. 2. Surfactant role
Correa, N. Mariano,Zorzan, Daniel H.,D'Anteo, Loredana,Lasta, Ermanno,Chiarini, Marco,Cerichelli, Giorgio
, p. 8231 - 8238 (2004)
Kinetics of the reduction of 3-chloroacetophenone (CAF) with sodium borohydride (NaBH4) were followed by UV-vis spectroscopy at 27.0 °C in different reverse micellar media, toluene/BHDC/ water and toluene/AOT/water, and compared with results in an isooctane/AOT/water reverse micellar system. AOT is sodium 1,4-bis-2-ethylhexylsulfosuccinate, and BHDC is benzyl-n-hexadecyl dimethylammonium chloride. The kinetic profiles were investigated as a function of variables such as surfactant and NaBH4 concentration and the amount of water dispersed in the reverse micelles, W 0 = [H2O]/[surfactant]. In all cases, the first-order rate constant, kobs, increases with the concentration of surfactant as a consequence of incorporating the substrate into the interface of the reverse micelles where the reaction takes place. The reaction is faster at the cationic interface than at the anionic one probably because the negative ion BH 4- is part of the cationic interface. The effect of the external solvent on the reaction shows that reduction is favored in the isooctane/ AOT/water reverse micellar system than that with an aromatic solvent. This is probably due to BH4- being more in the water pool of the toluene/AOT/water reverse micellar system. The kinetic profile upon water addition depends largely on the type of interface. In the BHDC system, kobs increases with W0 in the whole range studied while in AOT the kinetic profile has a maximum at W0 ～5, probably reflecting the fact that BH4- is part of the cationic interface while, in the anionic one, there is a strong interaction between water and the polar headgroup of AOT below W0 = 5 and, above that, BH 4- is repelled from the interface once the water pool has formed. Application of a kinetic model based on the pseudophase formalism, which considers the distribution of the ketone between the continuous medium and the interface and assumes that reaction takes place only at the interface, has enabled us to estimate rate constants at the interface of the reverse micellar systems. At W0 4 is wholly at the interface and, at W0 ≥ 10, where there are free water molecules, also the partitioning between the interface and the water pool was taken into account. The results were used to evaluate CAF and NaBH 4 distribution constants between the different pseudophases as well as the second-order reaction rate constant of the reduction reaction in the micellar interface.
A pH-Responsive Soluble-Polymer-Based Homogeneous Ruthenium Catalyst for Highly Efficient Asymmetric Transfer Hydrogenation (ATH)
Xie, Yinzheng,Wang, Mengpan,Wu, Xiaohui,Chen, Chen,Ma, Wenbo,Dong, Qifeng,Yuan, Mingming,Hou, Zhenshan
, p. 541 - 549 (2016)
A pH-responsive polymer has been synthesized successfully by means of copolymerization of dimethyl aminopropyl acrylamide (DMAPA) and N-p-styrenesulfonyl-1,2-diphenylethylenediamine (V-TsDPEN). The pH-responsive polymer coordination ruthenium complex was thus prepared and employed as an efficient catalyst for the asymmetric transfer hydrogenation (ATH) of various ketones. The polymer catalyst exhibited an attractive pH-induced phase-separable behavior in water: it could be dissolved in water when the pH of the solution was lower than 6.5 at the beginning of the reaction, but was precipitated completely from water when the pH of the solution was above 8.5 after reaction. Additionally, the catalysts were highly efficient for the ATH of a wide range of substrates that bore different functional groups and could be recycled easily from the aqueous solution by means of self-separation. They could be recycled eight times without significant changes in catalytic activity and enantioselectivity.
Ruthenium complexes bearing an unsymmetrical pincer ligand with a 2-hydroxypyridylmethylene fragment: Active catalysts for transfer hydrogenation of ketones
Shi, Jing,Hu, Bowen,Gong, Dawei,Shang, Shu,Hou, Guangfeng,Chen, Dafa
, p. 4828 - 4834 (2016)
Five ruthenium(ii) complexes were synthesized, including (HO-C5H3N-CH2-C5H3N-C5H4N)Ru(PPh3)Cl2 (3), [(HO-C5H3N-CH2-C5H3N-C5H4N)Ru(PPh3)2Cl][PF6] (4) and [(HO-C5H3N-CH2-C5H3N-C5H4N)Ru(PPh3)2OH][PF6] (5) bearing an unsymmetrical pincer NNN ligand with a 2-hydroxypyridylmethylene fragment, and [(CH3O-C5H3N-CH2-C5H3N-C5H4N)2Ru][Cl]2 (6) and [(CH3O-C5H3N-CH2-C5H3N-C5H4N)2Ru][PF6]2 (7) containing 2-methoxypyridylmethylene moieties. 4 reacts with H2O at room temperature to give 5 whose crystal structure reveals the existence of intramolecular hydrogen-bonding between its two -OH groups. 3 exhibits high catalytic activity for transfer hydrogenation of ketones.
Ru-η6-benzene-phosphine complex-catalyzed transfer hydrogenation of ketones
Wang, Lei,Yang, Qin,Fu, Hai-Yan,Chen, Hua,Yuan, Mao-Lin,Li, Rui-Xiang
, p. 626 - 631 (2011)
Three Ru-η6-benzene-phosphine complexes bearing tri-(p-methoxyphenyl)phosphine, triphenylphosphine and tri-(p- trifluoromethylphenyl)phosphine were synthesized and characterized by 31P{1H} NMR, 1H NMR, 13C{ 1H} NMR and elemental analyses. Complex 1 was further identified by X-ray crystallography. These complexes exhibit good to excellent activities for the transfer hydrogenation of ketones in refluxing 2-propanol, and the highest turnover frequency (TOF) is up to 5940 h-1. The effect of electronic factors of these complexes on the transfer hydrogenation of ketones reveals that the catalytic activity is promoted by electron-donating phosphine and the catalyst stability is improved by electron-withdrawing phosphine.
Exceptionally Active Assembled Dinuclear Ruthenium(II)-NNN Complex Catalysts for Transfer Hydrogenation of Ketones
Liu, Tingting,Chai, Huining,Wang, Liandi,Yu, Zhengkun
, p. 2914 - 2921 (2017)
Dinuclear ruthenium(II)-NNN complexes were efficiently assembled by means of coordinatively unsaturated 16-electron mononuclear ruthenium(II)-pyrazolyl-imidazolyl-pyridine complex and 4,4′-linked bipyridine ligands. The diruthenium(II)-NNN complex assembled through 4,4′-(CH2)3-bipyridine exhibited exceptionally high catalytic activity for the transfer hydrogenation (TH) of ketones in refluxing 2-propanol and reached TOF values up to 1.4 × 107 h-1, demonstrating a remarkable cooperative effect from the ruthenium(II)-NNN functionalities.
Cooperative N-H and CH2 Skeleton Effects on the Catalytic Activities of Bimetallic Ru(II)-NNN Complexes: Experimental and Theoretical Study
Chai, Huining,Liu, Tingting,Zheng, Daoyuan,Yu, Zhengkun
, p. 4268 - 4277 (2017)
Bimetallic ruthenium(II) complexes bearing a bis(pyrazolylimidazolylpyridine) ligand bridged by a rotatable single C-C bond or methylene linker were synthesized, structurally characterized, and exhibited diverse catalytic activities for the transfer hydrogenation (TH) reactions of ketones in refluxing isopropyl alcohol. Both the unprotected NH functionality and bridging methylene moiety demonstrated an acceleration effect on such TH reactions. Combination of the NH and CH2 skeleton functionalities into the bimetallic Ru(II)-NNN complexes remarkably enhanced the catalytic activities of the complex catalysts. Density functional theory calculations have suggested that the difference in the catalytic activities of these Ru(II)-NNN complexes is attributed to the inherent nucleophilic character of the coordinative nitrogen atoms in the bis(NNN) ligand, and the metal-metal interaction resulted from the number of net natural bond orbital charges on these nitrogen atoms.
What to sacrifice? Fusions of cofactor regenerating enzymes with Baeyer-Villiger monooxygenases and alcohol dehydrogenases for self-sufficient redox biocatalysis
Mourelle-Insua, ángela,Aalbers, Friso S.,Lavandera, Iván,Gotor-Fernández, Vicente,Fraaije, Marco W.
, p. 1832 - 1839 (2019)
A collection of fusion biocatalysts has been generated that can be used for self-sufficient oxygenations or ketone reductions. These biocatalysts were created by fusing a Baeyer-Villiger monooxygenase (cyclohexanone monooxygenase from Thermocrispum municipale: TmCHMO) or an alcohol dehydrogenase (alcohol dehydrogenase from Lactobacillus brevis: LbADH) with three different cofactor regeneration enzymes (formate dehydrogenase from Burkholderia stabilis: BsFDH; glucose dehydrogenase from Sulfolobus tokodaii: StGDH, and phosphite dehydrogenase from Pseudomonas stutzeri: PsPTDH). Their tolerance against various organic solvents, including a deep eutectic solvent, and their activity and selectivity with a variety of substrates have been studied. Excellent conversions and enantioselectivities were obtained, demonstrating that these engineered fusion enzymes can be used as biocatalysts for the synthesis of (chiral) valuable compounds.
Highly enantioselective reduction of ketones in air catalyzed by Rh-based macrocycles
Zhang, Wen-Jing,Ruan, Sun-Hong,Shen, Wei-Yi,Wang, Zhe,An, Dong-Li,Li, Yan-Yun,Gao, Jing-Xing
, p. 153 - 158 (2019)
The asymmetric transfer hydrogenation (ATH) of ketones catalyzed by Rh-based macrocycles proceeded smoothly in the presence of air with high catalytic activity and enantioselectivity. Even though the S/C ratio (substrate to catalyst molar ratio) was incre
Enhancing cofactor regeneration of cyanobacteria for the light-powered synthesis of chiral alcohols
Fan, Jianhua,Zhang, Yinghui,Wu, Ping,Zhang, Xiaoyan,Bai, Yunpeng
, (2021/11/24)
Cyanobacteria Synechocystis sp. PCC 6803 was exploited as green cell factory for light-powered asymmetric synthesis of aromatic chiral alcohols. The effect of temperature, light, substrate and cell concentration on substrate conversions were investigated. Under the optimal condition, a series of chiral alcohols were synthesized with conversions up to 95% and enantiomer excess (ee) > 99%. We found that the addition of Na2S2O3 and Angeli's Salt increased the NADPH content by 20% and 25%, respectively. As a result, the time to reach 95% substrate conversion was shortened by 12 h, which demonstrated that the NADPH regeneration and hence the reaction rates can be regulated in cyanobacteria. This blue-green algae based biocatalysis showed its potential for chiral compounds production in future.
Mechanochemical, Water-Assisted Asymmetric Transfer Hydrogenation of Ketones Using Ruthenium Catalyst
Kolcsár, Vanessza Judit,Sz?ll?si, Gy?rgy
, (2022/01/04)
Asymmetric catalytic reactions are among the most convenient and environmentally benign methods to obtain optically pure compounds. The aim of this study was to develop a green system for the asymmetric transfer hydrogenation of ketones, applying chiral Ru catalyst in aqueous media and mechanochemical energy transmission. Using a ball mill we have optimized the milling parameters in the transfer hydrogenation of acetophenone followed by reduction of various substituted derivatives. The scope of the method was extended to carbo- and heterocyclic ketones. The scale-up of the developed system was successful, the optically enriched alcohols could be obtained in high yields. The developed mechanochemical system provides TOFs up to 168 h?1. Our present study is the first in which mechanochemically activated enantioselective transfer hydrogenations were carried out, thus, may be a useful guide for the practical synthesis of optically pure chiral secondary alcohols.
Ambient-pressure highly active hydrogenation of ketones and aldehydes catalyzed by a metal-ligand bifunctional iridium catalyst under base-free conditions in water
Wang, Rongzhou,Yue, Yuancheng,Qi, Jipeng,Liu, Shiyuan,Song, Ao,Zhuo, Shuping,Xing, Ling-Bao
, p. 1 - 7 (2021/05/17)
A green, efficient, and high active catalytic system for the hydrogenation of ketones and aldehydes to produce corresponding alcohols under atmospheric-pressure H2 gas and ambient temperature conditions was developed by a water-soluble metal–ligand bifunctional catalyst [Cp*Ir(2,2′-bpyO)(OH)][Na] in water without addition of a base. The catalyst exhibited high activity for the hydrogenation of ketones and aldehydes. Furthermore, it was worth noting that many readily reducible or labile functional groups in the same molecule, such as cyan, nitro, and ester groups, remained unchanged. Interestingly, the unsaturated aldehydes can be also selectively hydrogenated to give corresponding unsaturated alcohols with remaining C=C bond in good yields. In addition, this reaction could be extended to gram levels and has a large potential of wide application in future industrial.
