scholarly journals MW-Promoted Cu(I)-Catalyzed P–C Coupling Reactions without the Addition of Conventional Ligands; an Experimental and a Theoretical Study

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 933
Author(s):  
Bianka Huszár ◽  
Réka Henyecz ◽  
Zoltán Mucsi ◽  
György Keglevich
Keyword(s):  
Microwave Irradiation ◽  
Theoretical Study ◽  
Oxidative Addition ◽  
Molar Ratio ◽  
Coupling Reactions ◽  
Optimum Conditions ◽  
Efficient Catalyst ◽  
Catalyst Complex

An experimental and a theoretical study on the so far less investigated Cu(I) salt-catalyzed Hirao reaction of iodobenzene and diarylphosphine oxides (DAPOs) revealed that Cu(I)Br or Cu(I)Cl is the most efficient catalyst under microwave irradiation. The optimum conditions included 165 °C and a 1:2 molar ratio for DAPOs and triethylamine. The possible ligations of Cu(I) were studied in detail. Bisligated P---Cu(I)---P (A), P---Cu(I)---N (B) and N---Cu(I)---N (C) complexes were considered as the catalysts. Calculations on the mechanism suggested that complexes A and B may catalyze the P–C coupling, but the latter one is more advantageous both according to experiments and calculations pointing out the Cu(I) ® Cu(III) conversion in the oxidative addition step. The P–C coupling cannot take place with PhBr, as in this case, the catalyst complex cannot be regenerated.

Synthesis of Phosphonates, Phosphinates and Tertiary Phosphine Oxides by Pd- or Ni-Catalyzed Microwave-Assisted P–C Coupling Reactions without the Addition of Conventional Ligands

2021 ◽  
Vol 25 ◽  
Author(s):  
Réka Henyecz ◽  
György Keglevich
Keyword(s):  
Tautomeric Form ◽  
Catalyst Precursor ◽  
Coupling Reactions ◽  
Optimum Conditions ◽  
Pd Catalysts ◽  
Catalyst Complex ◽  
Two Factors ◽  
Dialkyl Phosphites ◽  
Catalyst Systems ◽  
P Ligands

Abstract: Microwave (MW)-assistance may be a powerful tool also in the Hirao P–C coupling reactions of vinyl/aryl halides with dialkyl phosphites in the presence of Pd-catalysts/P-ligands elaborated forty years ago. This review surveys the development of this reaction by showing the expansion of the reagents and catalysts, as well as the information accumulated. The stress was laid on the “green” aspects, the simplification of the catalyst systems, and the reliable mechanistic details in order to be able to establish the optimum conditions. The best protocol involves the use of some excess of the >P(O)H reagent to ensure the PdII→Pd0 reduction and, via its trivalent tautomeric form (>POH) also the P-ligand. The overall rate is the result of two factors, the activity of the catalyst complex formed, and the reactivity of the reactants in the P–C coupling reactions. Both components are influenced by the nature of the aryl substituents in Ar2P(O)H. NiII salts may also be used as the catalyst precursor, however, despite the PdII→Pd0→PdII route, in this case, a NiII→NiIV→NiII sequence was proved.

Chiral Mn(III) Salen Complex Immobilized on CuFe2O4@SiO2-NH2 NPs: A Cheap and Efficient Catalyst for N-arylation of Aryl Halides and Phenylboronic Acid Under Mild Conditions

2020 ◽  
Vol 17 (11) ◽  
pp. 857-863
Author(s):  
Mohammad Ali Nasseri ◽  
Seyyedeh Ameneh Alavi ◽  
Milad Kazemnejadi ◽  
Ali Allahresani
Keyword(s):  
Phenylboronic Acid ◽  
Significant Loss ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Efficient Catalyst ◽  
Aryl Chlorides ◽  
Mild Conditions ◽  
Cross Coupling Reactions ◽  
Salen Complex ◽  
Ft Ir

A convenient and efficient chiral CuFe2O4@SiO2-Mn(III) Ch.salen nanocatalyst has been developed for the C-N cross-coupling reactions of aryl halides/ phenylboronic acid with N-heterocyclic compounds in water and/or DMSO under mild conditions. The catalyst could be applied for the N-arylation of a variety of nitrogen-containing heterocycles with aryl chlorides, bromides, iodides and phenylboronic acid under mild conditions. Moderate to good yields were achieved for all substrates. The structure of catalyst was characterized using various techniques including FT-IR, FE-SEM, EDX, XRD, TEM and TGA. The catalyst can be simply recovered and reused for several times without significant loss of activity.

Degradation of chlorpyriphos in water by advanced oxidation processes

2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro
Keyword(s):  
Reaction Time ◽  
Light Source ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
The Other ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Other Hand ◽  
Initial Ph

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.

scholarly journals Rapid and Efficient Synthesis ofω-Alkylenediphosphoric Acids from Phosphorus Oxychloride

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Dalila Meziane ◽  
Abdelhamid Elias ◽  
Erwann Guénin
Keyword(s):  
Microwave Irradiation ◽  
Reaction Temperature ◽  
Phosphorus Oxychloride ◽  
Molar Ratio ◽  
Efficient Synthesis ◽  
Selective Method

The aim of this investigation was to develop an efficient, rapid, and selective method for the synthesis ofω-alkylenediphosphoric acids (HO)2(O)P-O-CH2n-O-P(O)(OH)2from reaction of several diols with phosphorus oxychloride. The reaction was investigated using three methodologies: (i) presence of a base, (ii) classical heating, and (iii) use of microwave irradiation. Influence of reaction temperature and molar ratio of reagents, as well as the nature of the solvent, was studied using these three different methods.

Optimization of biodiesel synthesis under simultaneous ultrasound-microwave irradiation using response surface methodology (RSM)

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Seyed Mohammad Safieddin Ardebili ◽  
Teymor Tavakoli Hashjin ◽  
Barat Ghobadian ◽  
Gholamhasan Najafi ◽  
Stefano Mantegna ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Microwave Irradiation ◽  
Response Surface ◽  
Palm Oil ◽  
Catalyst Concentration ◽  
Irradiation Time ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Biodiesel Synthesis

AbstractThis work investigates the effect of simultaneous ultrasound-microwave irradiation on palm oil transesterification and uncovers optimal operating conditions. Response surface methodology (RSM) has been used to analyze the influence of reaction conditions, including methanol/palm oil molar ratio, catalyst concentration, reaction temperature and irradiation time on biodiesel yield. RSM analyses indicate 136 s and 129 s as the optimal sonication and microwave irradiation times, respectively. Optimized parameters for full conversion (97.53%) are 1.09% catalyst concentration and a 7:3.1 methanol/oil molar ratio at 58.4°C. Simultaneous ultrasound-microwave irradiation dramatically accelerates the palm oil transesterification reaction. Pure biodiesel was obtained after only 2.2 min while the conventional method requires about 1 h.

ChemInform Abstract: A General and Efficient Catalyst for Palladium-Catalyzed C-O Coupling Reactions of Aryl Halides with Primary Alcohols.

ChemInform ◽  
2010 ◽  
Vol 42 (4) ◽  
pp. no-no
Author(s):  
Saravanan Gowrisankar ◽  
Alexey G. Sergeev ◽  
Pazhamalai Anbarasan ◽  
Anke Spannenberg ◽  
Helfried Neumann ◽  
...  
Keyword(s):  
Aryl Halides ◽  
Coupling Reactions ◽  
Primary Alcohols ◽  
Efficient Catalyst ◽  
Palladium Catalyzed

Microwave Assisted Synthesis of Schiff Bases: A Green Approach

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Mousumi Chakraborty ◽  
Sanjay Baweja ◽  
Sunita Bhagat ◽  
TejpalSingh Chundawat
Keyword(s):  
Microwave Irradiation ◽  
Microwave Power ◽  
Mass Spectra ◽  
Molar Ratio ◽  
Microwave Assisted Synthesis ◽  
Schiff’S Bases ◽  
Microwave Assisted ◽  
Green Approach ◽  
Schiff's Bases ◽  
Effects Of Temperature

Abstract In the present study Schiff’s bases are synthesized by the conventional as well as by microwave irradiation. Excellent yield within short reaction time is obtained using microwave irradiation along with other advantages like mild reaction condition, non-hazardous and safer environmental conditions. The effects of temperature, reactant molar ratio, and microwave power variation on yield are observed. Mathematical model has been developed using matlab software to obtain the yield as a function of microwave power. Kinetic study of the reaction has also been attempted. Schiff’s bases structures are confirmed by IR, 1HNMR, Mass Spectra and elemental analysis.

An easily prepared palladium-hydrogel nanocomposite catalyst for C–C coupling reactions

2014 ◽  
Vol 2 (44) ◽  
pp. 18952-18958 ◽  
Author(s):  
Mitasree Maity ◽  
Uday Maitra
Keyword(s):  
Palladium Nanoparticles ◽  
Room Temperature ◽  
Coupling Reaction ◽  
Coupling Reactions ◽  
Sodium Cyanoborohydride ◽  
Efficient Catalyst ◽  
Suzuki Coupling Reaction ◽  
Reaction In Water ◽  
Hydrogel Nanocomposite

Palladium nanoparticles were efficiently prepared in situ by sodium cyanoborohydride reduction of Pd(ii) at room temperature using calcium-cholate hydrogel fibers as templates. The PdNPs self-organize on the gel fibers, which supports the controlled growth as well as stabilization of PdNPs. The hybrid xerogel was used as an efficient catalyst for the Suzuki coupling reaction in water.

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