scholarly journals Emeraldine Base Form of Polyaniline Nanofibers as New, Economical, Green, and Efficient Catalyst for Synthesis of Z-Aldoximes

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Rajender Boddula ◽  
Palaniappan Srinivasan
Keyword(s):  
Room Temperature ◽  
Hydroxylamine Hydrochloride ◽  
Emeraldine Base ◽  
Green Process ◽  
Efficient Catalyst ◽  
Solvent Free Condition ◽  
Base Form ◽  
Novel Catalyst ◽  
First Time ◽  
Pani Base

A facile, clean, economical, efficient, and green process was developed for the preparation of Z-aldoximes at room temperature under solvent-free condition using emeraldine base form of polyaniline as novel catalyst. In this methodology, PANI base absorbed the by-product of HCl (polluting chemical) from hydroxylamine hydrochloride and converted to polyaniline-hydrochloride salt (PANI-HCl salt). This PANI-HCl salt could be easily recovered and used in new attempts without any purification in many areas such as catalyst, electrical and electronics applications meant for conducting polymers. As far as our knowledge is concerned, emeraldine base as catalyst in organic synthesis for the first time.

Immobilizing AgPd alloy on Vulcan XC-72 carbon: a novel catalyst for highly efficient hydrogen generation from formaldehyde aqueous solution

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 105638-105643 ◽  
Author(s):  
Shutao Gao ◽  
Tao Feng ◽  
Qiuhua Wu ◽  
Cheng Feng ◽  
Ningzhao Shang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Hydrogen Generation ◽  
Bimetallic Catalyst ◽  
Highly Efficient ◽  
Novel Catalyst ◽  
First Time

A novel bimetallic catalyst, AgPd nanoalloy supported on Vulcan XC-72 carbon (AgPd@C-72), has been successfully fabricated and used for catalyzing H2 generation from formaldehyde aqueous solution at room temperature for the first time.

scholarly journals L-Tyrosine as an Eco-Friendly and Efficient Catalyst for Knoevenagel Condensation of Arylaldehydes with Meldrum’s Acid in Solvent-Free Condition under Grindstone Method

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
G. Thirupathi ◽  
M. Venkatanarayana ◽  
P. K. Dubey ◽  
Y. Bharathi Kumari
Keyword(s):  
Room Temperature ◽  
Knoevenagel Condensation ◽  
Solvent Free ◽  
Meldrum's Acid ◽  
Meldrum’S Acid ◽  
Efficient Catalyst ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Active Methylene ◽  
Methylene Group

We investigate L-Tyrosine as an efficient catalyst for the Knoevenagel condensation of arylaldehydes with meldrum’s acid containing cyclic active methylene group in solvent-free condition under grindstone method at room temperature to produce substituted-5-benzylidene-2,2-dimethyl-[1,3]dioxane-4,6-diones 3(a–j).

Novel AgPd hollow spheres anchored on graphene as an efficient catalyst for dehydrogenation of formic acid at room temperature

2016 ◽  
Vol 4 (2) ◽  
pp. 657-666 ◽  
Author(s):  
Yiqun Jiang ◽  
Xiulin Fan ◽  
Xuezhang Xiao ◽  
Teng Qin ◽  
Liuting Zhang ◽  
...  
Keyword(s):  
Formic Acid ◽  
Room Temperature ◽  
Hollow Spheres ◽  
One Pot ◽  
Chemical Route ◽  
Efficient Catalyst ◽  
Highly Dispersed ◽  
Wet Chemical ◽  
Wet Chemical Route ◽  
First Time

Highly dispersed AgPd hollow spheres anchored on graphene (denoted as AgPd-Hs/G) were successfully synthesized through a facile one-pot wet-chemical route for the first time.

scholarly journals Cu(I) Complexes of Multidentate N,C,N- and P,C,P-Carbodiphosphorane Ligands and their Photoluminescence

2020 ◽  
Author(s):  
Marius Klein ◽  
Nemrud Demirel ◽  
Alexander Schinabeck ◽  
Hartmut Yersin ◽  
Jörg Sundermeyer
Keyword(s):  
Room Temperature ◽  
Copper Complexes ◽  
Structural Information ◽  
Uv Light ◽  
Quantum Yields ◽  
Dinuclear Copper ◽  
Mononuclear Complexes ◽  
Base Form ◽  
The Common ◽  
First Time

A series of dinuclear copper(I) N,C,N- and P,C,P-carbodiphosphorane (CDP) complexes using multidentate ligands CDP(Py)2 (1) and (CDP(CH2PPh2)2 (13) have been isolated and characterized. Detailed structural information was gained by single crystal XRD analyses of nine representative examples. The common structural motive is the central double ylidic carbon atom with its characteristic two lone-pairs involved into binding of two geminal L-Cu(I) fragments at Cu-Cu distances in the range 2.55 – 2.67 Å. In order to enhance conformational rigidity within the characteristic Cu-C-Cu triangle, two types of chelating side arms were symmetrically attached to each phosphorus atom: two 2-pyridyl functions in ligand CDP(Py)2 (1) and its dinuclear copper complexes 2-9 and 11, as well as two diphenylphosphinomethylene functions in ligand CDP(CH2PPh2)2 (13) and its di- and mononuclear complexes 14-18. Neutral complexes were typically obtained via reaction of 1 with Cu(I) species CuCl, CuI, and CuSPh or via salt elimination reaction of [(CuCl)2(CDP(Py)2] (2) with sodium carbazolate. Cationic Cu(I) complexes were prepared upon treating 1 with two equivalents of [Cu(NCMe)4]PF6, followed by the addition of either two equivalent of an aryl phosphine (PPh3, P(C6H4OMe)3) or one equivalent of a bisphosphine ligands DPEPhos, XantPhos or dppf. For the first time carbodiphosphorane CDP(CH2PPh2)2 (13) could be isolated upon treating its precursor [CH(dppm)2]Cl (12) with NaNH2 in liquid NH3. A protonated and a deprotonated derivative of ligand 13 were prepared and their coordination was compared to neutral CDP ligand 13. NMR analysis and DFT calculations reveal, that the most stable tautomer of 13 does not show a CDP (or carbone) structure in its uncoordinated base form. For most of the prepared complexes, photoluminescence upon irradiation with UV light at room temperature was observed. Quantum yields (PL) were determined to 36% for dicationic [(CuPPh3)2(CDP(Py)2)](PF6)2 (4) and to 60% for neutral [(CuSPh)2(CDP(CH2PPh2)2] (16).

scholarly journals Cu(I) Complexes of Multidentate N,C,N- and P,C,P-Carbodiphosphorane Ligands and Their Photoluminescence

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3990 ◽  
Author(s):  
Marius Klein ◽  
Nemrud Demirel ◽  
Alexander Schinabeck ◽  
Hartmut Yersin ◽  
Jörg Sundermeyer
Keyword(s):  
Room Temperature ◽  
Copper Complexes ◽  
Structural Information ◽  
Uv Light ◽  
Quantum Yields ◽  
Dinuclear Copper ◽  
Mononuclear Complexes ◽  
Base Form ◽  
The Common ◽  
First Time

A series of dinuclear copper(I) N,C,N- and P,C,P-carbodiphosphorane (CDP) complexes using multidentate ligands CDP(Py)2 (1) and (CDP(CH2PPh2)2 (13) have been isolated and characterized. Detailed structural information was gained by single-crystal XRD analyses of nine representative examples. The common structural motive is the central double ylidic carbon atom with its characteristic two lone pairs involved in the binding of two geminal L-Cu(I) fragments at Cu–Cu distances in the range 2.55–2.67 Å. In order to enhance conformational rigidity within the characteristic Cu–C–Cu triangle, two types of chelating side arms were symmetrically attached to each phosphorus atom: two 2-pyridyl functions in ligand CDP(Py)2 (1) and its dinuclear copper complexes 2–9 and 11, as well as two diphenylphosphinomethylene functions in ligand CDP(CH2PPh2)2 (13) and its di- and mononuclear complexes 14–18. Neutral complexes were typically obtained via the reaction of 1 with Cu(I) species CuCl, CuI, and CuSPh or via the salt elimination reaction of [(CuCl)2(CDP(Py)2] (2) with sodium carbazolate. Cationic Cu(I) complexes were prepared upon treating 1 with two equivalents of [Cu(NCMe)4]PF6, followed by the addition of either two equivalents of an aryl phosphine (PPh3, P(C6H4OMe)3) or one equivalent of bisphosphine ligands bis[(2-diphenylphosphino)phenyl] ether (DPEPhos), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (XantPhos), or 1,1′-bis(diphenyl-phosphino) ferrocene (dppf). For the first time, carbodiphosphorane CDP(CH2PPh2)2 (13) could be isolated upon treating its precursor [CH(dppm)2]Cl (12) with NaNH2 in liquid NH3. A protonated and a deprotonated derivative of ligand 13 were prepared, and their coordination was compared to neutral CDP ligand 13. NMR analysis and DFT calculations reveal that the most stable tautomer of 13 does not show a CDP (or carbone) structure in its uncoordinated base form. For most of the prepared complexes, photoluminescence upon irradiation with UV light at room temperature was observed. Quantum yields (ΦPL) were determined to be 36% for dicationic [(CuPPh3)2(CDP(Py)2)](PF6)2 (4) and 60% for neutral [(CuSPh)2(CDP(CH2PPh2)2] (16).

Preparation and Characterization of a Novel Room Temperature Dicationic Ionic Liquid and its Application in the Synthesis of Xanthenediones Under Solvent-Free Conditions

2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Reaction Times ◽  
Significant Loss ◽  
Solvent Free ◽  
Acidity Function ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Hammett Acidity Function ◽  
Dicationic Ionic Liquid

Aim and Objective: In the present work, 1, 1’-sulfinyldiethylammonium bis (hydrogen sulfate) as a novel room temperature dicationic ionic liquid was synthesized and used as a catalyst for xanthenediones synthesis. Material and Method: The dicationic ionic liquid has been synthesized using ethylamine and thionyl chloride as precursors. Then, by the reaction of [(EtNH2)2SO]Cl2 with H2SO4, [(EtNH2)2SO][HSO4]2 was prepared and after that, it was characterized by FT-IR, 1H NMR, 13C NMR as well as Hammett acidity function. This dicationic ionic liquid was used as a catalyst for the synthesis of xanthenediones via condensation of structurally diverse aldehydes and dimedone under solvent-free conditions. The progress of the reaction was monitored by thin layer chromatography (ethyl acetate/n-hexane = 3/7). Results: An efficient solvent-free method for the synthesis of xanthenediones has been developed in the presence of [(EtNH2)2SO][HSO4]2 as a powerful catalyst with high to excellent yields, and short reaction times. Additionally, recycling studies have demonstrated that the dicationic ionic liquid can be readily recovered and reused at least four times without significant loss of its catalytic activity. Conclusion: This new dicationic ionic liquid can act as a highly efficient catalyst for xanthenediones synthesis under solvent-free conditions.

Synthesis of Dihydropyrimidinones (DHPMs) and Hexahydro Xanthene Catalyzed by 1,4-Diazabicyclo [2.2.2] Octane Triflate Under Solvent-Free Condition

2019 ◽  
Vol 16 (5) ◽  
pp. 776-786 ◽  
Author(s):  
Deepa ◽  
Geeta D. Yadav ◽  
Mohd J. Aalam ◽  
Pooja Chaudhary ◽  
Surendra Singh
Keyword(s):  
Ethyl Acetoacetate ◽  
Biginelli Reaction ◽  
Solvent Free ◽  
Efficient Catalyst ◽  
Solvent Free Condition ◽  
Solvent Free Conditions ◽  
Xanthene Derivatives ◽  
Different Temperatures ◽  
Flash Column Chromatography ◽  
Biginelli Condensation

Objective:DABCO salts were evaluated as catalysts for the Biginelli reaction between 4- methoxybenzaldehyde, urea and ethyl acetoacetate under solvent-free conditions. 1,4-Diazabicyclo [2.2.2] octane triflate was found to be a simple, inexpensive, highly efficient catalyst for Biginelli reaction for a variety aromatic aldehyde with urea and ethyl acetoacetate at 80°C afforded corresponding 3,4-dihydropyrimidinones in 50-99% yields after 30-120 minutes. 1,3-Cyclohexadione was used in place of ethyl acetoacetate in the absence of urea this methodology is giving hexahydro xanthene derivatives in good to excellent yields after 3-4 hours.Methods:DABCO salt 4 (5 mol%), 4-methoxybenzaldehyde (0.73 mmol) and urea (0.73 mmol) were stirred for 10 minutes at 80°C, then ethyl acetoacetate (1.5 equiv.) was added and reaction mixture was stirred at 80°C for specified time. The resulting solution was stirred continuously and progress of the reaction was followed by TLC. The crude reaction mixture was purified by flash column chromatography on silica gel (hexane/ethyl acetate (1:2)) to give pure desired product.Results:Reaction conditions of the Biginelli reaction were optimized using 4-methoxybenzaldehyde (0.73 mmol), urea (0.73 mmol), and ethyl acetoacetate (5 equiv.) as model substrates catalyzed by 1,4-Diazabicyclo [2.2.2] octane triflate (5 mol%) in a different solvents, screening of different catalysts and different temperatures. Neat condition was found to be the best for the Biginelli condensation and corresponding 3,4- dihydropyrimidinones was obtained in good to excellent yields. When the reaction was carried out with benzaldehyde derivatives and cyclohexane-1,3-dione in place of ethyl acetoacetate in the absence of urea, solely corresponding hexahydro xanthene derivatives were obtained in 61-91% yields.Conclusion:In conclusion, we have applied salts of 1,4-Diaza-bicyclo [2.2.2] octane as catalysts in the Biginelli condensation and corresponding 3,4-dihydropyrimidinones were obtained in 50- 99% yields under solvent free conditions. This methodology is having advantages like simple work-up; low loading of catalyst and reaction was performed at moderate temperature under solvent-free conditions.

Sign in / Sign up

Export Citation Format

Share Document