Synthesis and catalytic activity of N‐heterocyclic silylene (NHSi) iron (II) hydride for hydrosilylation of aldehydes and ketones

2021 ◽  
Author(s):  
Xinyu Du ◽  
Xinghao Qi ◽  
Kai Li ◽  
Xiaoyan Li ◽  
Hongjian Sun ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Aldehydes And Ketones

scholarly journals Studies of the Catalytic Activity of Iron (III) Porphyrins for the Protection of Carbonyl Groups in Homogeneous Media

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 334 ◽  
Author(s):  
Gabriel Ferreira ◽  
Charles Carvalho ◽  
Shirley Nakagaki
Keyword(s):  
Catalytic Activity ◽  
Lewis Acids ◽  
High Reactivity ◽  
Central Metal ◽  
Carbonyl Groups ◽  
Lewis Acid Catalysts ◽  
Cyclic Acetals ◽  
Aldehydes And Ketones ◽  
Additional Coordination ◽  
Fine Chemistry

The protection of carbonyl groups that produce acetal products is a key reaction in fine chemistry due to the high reactivity of aldehydes and ketones in certain media. This process can be catalyzed by protic or Lewis acids. Since metalloporphyrins often possess free axial positions in the central metal, they can be applied as Lewis acid catalysts, allowing the additional coordination of substrates. Therefore, three ferric complexes were selected to be evaluated as catalysts for the acetalization of benzaldehyde with ethanol and triethyl orthoformate (TEOF) in the homogeneous phase: (i) 5,10,15,20-tetrakis(phenylporphyrin) iron (III) chloride (Fe0F); (ii) 5,10,15,20-tetrakis(2,6-difluorphenylporphyrin) iron (III) chloride (Fe2F); and (iii) 5,10,15,20-tetrakis(pentafluorphenylporphyrin) iron (III) chloride (Fe5F). The complex Fe5F showed the highest catalytic activity, and kinetic parameters were evaluated for this reaction, exhibiting an increasing rate of reaction of about 550-fold in comparison with the non-catalyzed reaction. The reaction scope was also investigated, and Fe5F was found to be active for the acetalization of benzaldehyde and acetophenone, with different protective agents such as alcohols, glycols, glycerol, and epoxide being selective for the formation of cyclic acetals. The protection of benzaldehyde with ethylene glycol and propylene glycol were also studied at different temperatures, and turnover frequency (TOF) values of up to 360 h−1 were determined at 40 °C in homogenous media without the need for solvent or drying agents.

scholarly journals Synthesis, spectral characterization and catalytic studies of new ruthenium(II) chalcone thiosemicarbazone complexes

2010 ◽  
Vol 8 (1) ◽  
pp. 229-240 ◽  
Author(s):  
Manisekar Muthukumar ◽  
Periasamy Viswanathamurthi
Keyword(s):  
Catalytic Activity ◽  
Carbonyl Compounds ◽  
Transfer Hydrogenation ◽  
Secondary Alcohols ◽  
Octahedral Structure ◽  
Imine Nitrogen ◽  
Phenolic Oxygen ◽  
Thiosemicarbazone Complexes ◽  
Aldehydes And Ketones ◽  
Nmr Methods

AbstractA series of new hexa-coordinated ruthenium(II) complexes of the type [Ru(CO)(EPh3)(B)(L)] (E = P or As; B = PPh3, AsPh3 or Py; L = chalcone thiosemicarbazone) have been prepared by reacting [RuHCl(CO)(EPh3)2(B)] (E = P or As; B = PPh3, AsPh3 or Py) with chalcone thiosemicarbazones in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (IR, UV-vis, 1H, 31P and 13C NMR) methods. On the basis of data obtained, an octahedral structure was assigned for all of the complexes. The chalcone thiosemicarbazones behave as dianionic tridentate O, N, S donors and coordinate to ruthenium via the phenolic oxygen of chalcone, the imine nitrogen of thiosemicarbazone and thienol sulfur. The new complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols to their corresponding aldehydes and ketones and they were also found to be efficient catalysts for the transfer hydrogenation of carbonyl compounds.

Synthesis, characterization and catalytic activity of novel ruthenium complexes bearing NNN click based ligands

2019 ◽  
Vol 48 (36) ◽  
pp. 13580-13588 ◽  
Author(s):  
Roberto Sole ◽  
Marco Bortoluzzi ◽  
Anke Spannenberg ◽  
Sergey Tin ◽  
Valentina Beghetto ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ruthenium Complexes ◽  
Aldehydes And Ketones

New ruthenium complexes based on click-synthesized triazole-containing NNN ligands were successfully used for the hydrogenation of aldehydes and ketones.

Thioacetalization of aldehydes and ketones in the presence of hydroxo complexes of platinum(II): An example of Lewis acid catalytic activity

2001 ◽  
Vol 79 (5-6) ◽  
pp. 621-625 ◽  
Author(s):  
Lorenzo Battaglia ◽  
Francesco Pinna ◽  
Giorgio Strukul
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Reaction Rate ◽  
Platinum Complex ◽  
Acid Catalyst ◽  
High Catalytic Activity ◽  
Hydroxo Complexes ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst

The complex [(dppb)Pt(µ-OH)]2(BF4)2 displays high catalytic activity in the thioacetalization of a variety of aldehydes and ketones with mercaptoethanol under very mild conditions. The reaction rate is greatly enhanced by the addition to the reaction mixture of magnesium perchlorate as drying agent and molar turnovers as high as 9700 can be observed. The effect of different desiccating agents is also reported. The reactivity pattern observed, the similarity with other reactions and NMR spectroscopic investigations confirm the possible role of the complex as Lewis acid catalyst in promoting the reaction.Key words: thioacetalization, catalysis, aldehydes, ketones, platinum complex.

Acetalization of aldehydes and ketones over H4[SiW12O40] and H4[SiW12O40]/SiO2

2014 ◽  
Vol 4 (8) ◽  
pp. 2618-2625 ◽  
Author(s):  
Shen Zhao ◽  
Yueqing Jia ◽  
Yu-Fei Song
Keyword(s):  
Catalytic Activity ◽  
Solvent Free ◽  
Solvent Free Conditions ◽  
Aldehydes And Ketones

A Keggin cluster of H4[SiW12O40] (H-SiW12) has been developed to catalyze the acetalization of aldehydes and ketones under solvent-free conditions, and could be recycled at least ten times without an obvious decrease in catalytic activity.

Novel approach to synthesizing polymer-functionalized Fe3O4/SiO2–NH2via an ultrasound-assisted method for catalytic selective oxidation of alcohols to aldehydes and ketones in a DMSO/water mixture

RSC Advances ◽  
2015 ◽  
Vol 5 (112) ◽  
pp. 92335-92343 ◽  
Author(s):  
Mahsa Dehghan ◽  
Atieh Motaharinejad ◽  
Mostafa Saadat ◽  
Reza Ahdenov ◽  
Mirzaagha Babazadeh ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Selective Oxidation ◽  
Aerobic Oxidation ◽  
Core Shell ◽  
Water Mixture ◽  
Novel Approach ◽  
Oxidation Of Alcohols ◽  
Aldehydes And Ketones ◽  
Ultrasound Assisted ◽  
Catalytic Selective Oxidation

A Fe3O4/SiO2/PATL/MnO2 core/shell nanocomposite was synthesized via an ultrasound-assisted method and its catalytic activity for the aerobic oxidation of alcohols to aldehydes and ketones was evaluated .

High resolution electron microscopy of lanthanum phosphate crystals

1978 ◽  
Vol 36 (1) ◽  
pp. 274-275
Author(s):  
J. C. Wheatley ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
High Resolution ◽  
Petroleum Industry ◽  
High Resolution Electron Microscopy ◽  
Lanthanum Phosphate ◽  
Good Catalyst ◽  
Resolution Electron ◽  
Good Catalytic Activity ◽  
Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

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