120523-12-8Relevant articles and documents
Ruthenium ONO-type pincer complex: Synthesis, structural characterization, and catalysis
Zhang, Yao,Li, Xingwei,Hong, Soon Hyeok
, p. 1779 - 1783 (2010)
A novel nitrone-based pincer ligand was developed by a single-step synthesis from N-(tert-butyl)hydroxylamine acetate and 2,6- pyridinedicarboxaldehyde. The developed ligand allowed us to synthesize a cationic ruthenium pincer complex. A distorted octahedral coordination environment around the ruthenium center was observed. The complex showed excellent catalytic activity in transfer hydrogenation reactions with turnover numbers up to 590,000.
Asymmetric transfer hydrogenation of aromatic ketones catalyzed by chiral ruthenium(II) complexes
Hashiguchi, Shohei,Fujii, Akio,Takehara, Jun,Ikariya, Takao,Noyori, Ryoji
, p. 7562 - 7563 (1995)
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Synthesis, structure, and photophysical properties of tributyl phosphine bisbenzothienyl iridium(III) complex and its application on transfer hydrogenation of acetophenone
Wang, Dawei,Zhao, Keyan,Yang, Shuyan,Ding, Yuqiang
, p. 400 - 404 (2015)
A phosphine bisbenzothienyl iridium(III) complex was synthesized and characterized by IR and1H NMR spectroscopy as well as X-ray diffraction methods. The TG data suggests that the complex has an excellent thermal stability than that with an amidate ancillary ligand. Photophysical properties showed that the complex emits typical green emission.
Synthesis, characterization of novel Nickel(II) complexes with PxNy-Type ligands and their application in reduction of ketones
Wang, Zhe,Yu, Shen-Luan,Wei, Zan-Bin,An, Dong-Li,Li, Yan-Yun,Gao, Jing-Xing
, (2019)
Novel nickel(II) complexes 1 and 2 could be conveniently prepared using PxNy-type ligands and easily available NiCl2·6H2O as a starting material. Furthermore, we obtained the single crystals suitable for X-ray diffraction to confirm the structure of these two nickel(II) complexes. With the well-designed nickel(II) complex, the hydrogenation of a wide range of ketones proceeded smoothly under relative mild reaction conditions, affording the corresponding alcohols with high isolated yields.
Dinuclear Di(N-heterocyclic carbene) iridium(III) complexes as catalysts in transfer hydrogenation
Volpe, Andrea,Baldino, Salvatore,Tubaro, Cristina,Baratta, Walter,Basato, Marino,Graiff, Claudia
, p. 247 - 251 (2016)
Two novel di(N-heterocyclic carbene) complexes of formula (μ-PyrIm-CH2-ImPyr)[IrCp?Cl]2(PF6)2 (1) and μ-MeIm-CH2(p-C6H2)CH2-ImMe[IrCp? Cl]2 (2) (Im = imidazol-2-ylidene) have been synthesised by transmetallation of the dicarbene ligand from the corresponding dicarbene silver complex, using [IrCp?(μ-Cl)Cl]2 as an iridium precursor. The structure of complex 2 has been determined by X-ray diffraction and is characterized by a double ortho-metallation of the p-xylylene bridge between the carbene units. Both complexes show good activity in the transfer hydrogenation of ketones to alcohols in 2-propanol. Dinuclear iridium(III) complexes bearing a bridging di(NHC) ligand have been synthesised and tested as catalysts in transfer hydrogenation reactions.
Preparation, Characterization, and Catalytic Reactions of NCN Pincer Iron Complexes Containing Stannyl, Silyl, Methyl, and Phenyl Ligands
Ito, Jun-Ichi,Hosokawa, Satomi,Khalid, Hairuzana Binti,Nishiyama, Hisao
, p. 1377 - 1383 (2015)
Preparation and reactivity of chiral and achiral NCN pincer Fe complexes containing bis(oxazolinyl)phenyl (abbreviated as phebox) ligands with SnMe3, SiMe3, Me, and Ph ligands were investigated. Irradiation of (phebox)SnMe3 (2) with 1 equiv of Fe(CO)5 led to oxidative addition to give NCN pincer stannyl complex (phebox)Fe(CO)2(SnMe3) (3). Similarly, oxidative addition of (phebox)SiMe3 (4) with Fe(CO)5 resulted in the formation of silyl complex (phebox)Fe(CO)2SiMe3 (5). Me and Ph complexes (phebox)Fe(CO)2R (7, R = Me; 8, R = Ph) were synthesized by transmetalation of the bromide complex (phebox)Fe(CO)2Br (1) with ZnMe2 and ZnPh2, respectively. These phebox Fe complexes served as catalysts for hydrosilylation of a ketone and C-H silylation of N-methylindole. (Chemical Equation Presented).
ENANTIOSELECTIVE REDUCTIONS OF KETONES WITH OXAZABOROLIDINES DERIVED FROM (R) AND (S)-α,α-DIPHENYL-2-PIPERIDINE METHANOL
Rao, A. V. Rama,Gurjar, M. K.,Sharma, P. A.,Kaiwar, Vijay
, p. 2341 - 2344 (1990)
Oxazaborolidnes obtained from (R) and (S)-α,α-diphenyl-2-piperidine methanol have been used as catalysts in the enantioselective reductions of ketones with borane.
Electrochemical response of a Ru(II) benzothiazolyl-2-pyridinecarbothioamide pincer towards carbon dioxide and transfer hydrogenation of aryl ketones in air
Celestine, Michael,Holder, Alvin A.,Lawrence, Mark A. W.,Lorraine, Shannen C.
, (2020)
A ruthenium(II) complex of 6-(4,7-dimethoxy-2-benzothiazolyl)-N-(2,5-dimethoxyphenyl)-2-pyridinecarbothioamide (pbcta), of the formula [Ru(pbcta)Cl2(dmf)] (1, where DMF = dimethyl formamide) was prepared from RuCl3?xH2O and pbcta in DMF at reflux under argon atmosphere. The identity of 1 was confirmed from its elemental analysis, ESI MS, and a series of spectroscopic measurements. Voltammetric measurements on 1 in DMF and DFT studies on the structure optimized in the gas phase revealed predominantly ligand based electron transfer processes under argon. In the presence of a proton source, proton coupled electron transfer to the ligand occurs. Under a carbon dioxide atmosphere, voltammetric studies revealed that 1 is inactive for CO2 reduction, and the redox responses observed in the presence of the proton source and/or CO2 are ligand based leading to reactions with the coordinated pbcta. Transfer hydrogenation (TH) of aryl ketones was efficiently carried out in 2-propanol using 1 at reflux. TH of the aryl ketone substrates proceeded in air with almost quantitative conversions at 0.2–1.0 molpercent catalyst.
Strategy towards the enantioselective synthesis of schiglautone A
Le Chapelain, Camille
, p. 6242 - 6256 (2017)
Herein is described a convergent enantioselective route to an advanced intermediate in the synthesis of schiglautone A, a Schisandra triterpenoid with an unusual architecture. The synthetic route to this intermediate displaying 6 of the 7 stereocenters builds upon two fragments, an aldehyde elaborated from the Wieland-Miescher ketone, and a ketone. The preparation of the latter features a lithiation-borylation enzymatic resolution sequence, which led to the formation of the desired product with high enantio- and diastereoselectivities. After aldol coupling of the two fragments, the final quaternary stereocenter was installed by cyclopropane opening. The functionalized intermediate was isolated as a single diastereoisomer and thus offers a valuable starting point for further synthetic exploration.
Fast transfer hydrogenation using a highly active orthometalated heterocyclic carbene ruthenium catalyst
Baratta, Walter,Schütz, Jan,Herdtweck, Eberhardt,Herrmann, Wolfgang A.,Rigo, Pierluigi
, p. 5570 - 5575 (2005)
The free carbene 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene reacts with trans,cis-RuHCl(PPh3)2(ampy) (ampy = 2-(aminomethyl)pyridine) affording an orthometalated N-heterocyclic carbene complex characterized by an X-ray di
Ruthenium(II) complexes with pyridine-based Schiff base ligands: Synthesis, structural characterization and catalytic hydrogenation of ketones
Buldurun, Kenan,?zdemir, Metin
, (2020)
This study investigated the synthesis and characterization of which the result of the reaction of Schiff base ligands containing pyridine with [RuCl2(p-cymene)]2. The spectroscopic techniques used for the characterization process wer
Hydrogenation of acetophenone and its derivatives with 2-propanol using aminomethylphosphine-ruthenium catalysis
Keles, Mustafa,Keles, Tugba,Serindag, Osman,Yasar, Sedat,Oezdemir, Ismail
, p. 165 - 170 (2010)
The reaction of 3′-aminopropyltriethoxysilane with the phosphonium salt ([Ph2P(CH2OH)2]Cl) gives an aminomethylphosphine-type ligand ((CH3CH2O) 3Si(CH2)3N(CH2PPh2)sub
Cinchona-Alkaloid-Derived NNP Ligand for Iridium-Catalyzed Asymmetric Hydrogenation of Ketones
Zhang, Lin,Zhang, Ling,Chen, Qian,Li, Linlin,Jiang, Jian,Sun, Hao,Zhao, Chong,Yang, Yuanyong,Li, Chun
supporting information, p. 415 - 419 (2022/01/12)
Most ligands applied for asymmetric hydrogenation are synthesized via multistep reactions with expensive chemical reagents. Herein, a series of novel and easily accessed cinchona-alkaloid-based NNP ligands have been developed in two steps. By combining [Ir(COD)Cl]2, 39 ketones including aromatic, heteroaryl, and alkyl ketones have been hydrogenated, all affording valuable chiral alcohols with 96.0-99.9% ee. A plausible reaction mechanism was discussed by NMR, HRMS, and DFT, and an activating model involving trihydride was verified.
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.
Phase Separation-Promoted Redox Deracemization of Secondary Alcohols over a Supported Dual Catalysts System
Zhao, Zhitong,Wang, Chengyi,Chen, Qipeng,Wang, Yu,Xiao, Rui,Tan, Chunxia,Liu, Guohua
, p. 4055 - 4063 (2021/08/12)
Unification of oxidation and reduction in a one-pot deracemization process has great significance in the preparation of enantioenriched organic molecules. However, the intrinsic mutual deactivation of oxidative and reductive catalysts and the extrinsic incompatible reaction conditions are unavoidable challenges in a single operation. To address these two issues, we develop a supported dual catalysts system to overcome these conflicts from incompatibility to compatibility, resulting in an efficient one-pot redox deracemization of secondary alcohols. During this transformation, the TEMPO species onto the outer surface of silica nanoparticles catalyze the oxidation of racemic alcohols to ketones, and the chiral Rh/diamine species in the nanochannels of the thermoresponsive polymer-coated hollow-shell mesoporous silica enable the asymmetric transfer hydrogenation (ATH) of ketones to chiral alcohols. To demonstrate the general feasibility, a series of orthogonal oxidation/ATH cascade reactions are compared to prove the compatible benefits in the elimination of their deactivations and the balance of the cascade directionality. As presented in this study, this redox deracemization process provides various chiral alcohols with enhanced yields and enantioselectivities relative to those from unsupported dual catalysts systems. Furthermore, the dual catalysts can be recycled continuously, making them an attractive feature in the application.
