Catalytic activity of cupric oxide in addition reactions of alkyl cyanoacetates with 1-alkenes

1979 ◽  
Vol 44 (12) ◽  
pp. 3695-3704 ◽  
Author(s):  
Milan Hájek ◽  
Jaroslav Málek
Keyword(s):  
High Selectivity ◽  
Addition Reaction ◽  
Fast Rate ◽  
Cupric Oxide ◽  
Ethyl Cyanoacetate ◽  
Radical Mechanism ◽  
Addition Reactions ◽  
Free Radical Mechanism ◽  
Reaction Proceeds ◽  
High Yields

In the presence of cupric oxide as the catalyst, ethyl cyanoacetate reacts with 1-alkenes to form 1 : 1 adducts in high yields. The active catalytic component was found to be a soluble copper species generated in the absence of oxygen in 10-3 to 10-5 M concentrations by a partial dissolution of cupric oxide in ethyl cyanoacetate. The homogeneous catalytic reaction proceeds already at temperatures about 80 °C at a fast rate and with high selectivity. Results of inhibition experiments in the presence of α-naphthol and galvinoxyl support strongly the view on a free-radical mechanism of the addition reaction.

Copper-catalyzed radical approach to allenyl iodides

2019 ◽  
Vol 55 (78) ◽  
pp. 11774-11777 ◽  
Author(s):  
Yulong Song ◽  
Shihua Song ◽  
Xinyu Duan ◽  
Xiaoyan Wu ◽  
Feng Jiang ◽  
...  
Keyword(s):  
Addition Reaction ◽  
Radical Mechanism ◽  
Mild Conditions ◽  
High Yields ◽  
Radical Approach

A copper-catalyzed 1,4-addition reaction of arylsulfonyl iodides with 1,3-enynes afforded various allenyl halides in high yields under mild conditions via a radical mechanism.

scholarly journals Polyoxometalates catalysts in the oxidation of cyclooctane by hydrogen peroxide

2012 ◽  
Vol 77 (11) ◽  
pp. 1599-1607 ◽  
Author(s):  
Wimonrat Trakarnpruk ◽  
Apiwat Wannatem ◽  
Jutatip Kongpeth
Keyword(s):  
Hydrogen Peroxide ◽  
Free Radical ◽  
Reaction Time ◽  
High Selectivity ◽  
Experimental Results ◽  
Molar Ratio ◽  
Radical Mechanism ◽  
Tetrabutylammonium Salt ◽  
Free Radical Mechanism ◽  
Radical Traps

A Keggin-type tungstocobaltate, [Co(2,2'- bipy)3]2H2[CoW12O40]?9.5H2O ([Co]CoW) and tetrabutylammonium salt of vanadium-substituted tungstophosphates [(n-C4H9)4N]4[PVW11O40], [(n-C4H9)4N]5[PV2W10O40] (PVW, PV2W) were used as catalyst for oxidation of cyclooctane with H2O2 as oxidant in acetonitrile. The activity of [(n-C4H9)4N4H[PCo(H2O)W11O39]?2H2O (PCoW) was also compared. The products of the reaction were cyclooctanone, cyclooctanol and cyclooctyl hydroperoxide. The experimental results showed that at H2O2/cyclooctane molar ratio = 3 at 80?C, in 9 h the [Co]CoW yielded higher conversion and selectivity to cyclooctanone. The V-based catalysts are more active than the Co-based tungstophosphate. The PV2W gave rise to high selectivity to cyclooctyl hydroperoxide. Cyclooctane conversion was increased by increasing reaction time or H2O2/cyclooctane molar ratio. In the presence of tungstocobaltate catalyst, 88% cyclooctane conversion and 82% selectivity of cyclooctanone were obtained after 12 h using H2O2/cyclooctane molar ratio of 9. This catalyst is stable upon treatment with H2O2. Experiments with radical traps suggest the involvement of a free-radical mechanism.

Cobalt(II) catalyzed oxidation of 2-substituted 1,3-dioxolanes with molecular oxygen

1993 ◽  
Vol 71 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Pei Li ◽  
Howard Alper
Keyword(s):  
Free Radical ◽  
Molecular Oxygen ◽  
Radical Mechanism ◽  
Free Radical Mechanism ◽  
High Yields ◽  
Catalyzed Oxidation

Cobalt(II) chloride catalyzed oxidation of 2-substituted 1,3-dioxolanes in 1,2-dimethoxyethane afforded formate esters and acids in high yields. It was found that the presence of catalytic amounts of ZnCl2 increased the rate of oxidation. A free-radical mechanism is proposed, involving participation of superoxocobalt, and the esterification of the alcohol and acid.

scholarly journals Synthesis and Antiproliferative Evaluation of 2-Deoxy-N-glycosylbenzotriazoles/imidazoles

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3742
Author(s):  
Caleigh S. Garton ◽  
Noelle K. DeRose ◽  
Dylan Dominguez ◽  
Maria L. Turbi-Henderson ◽  
Ashley L. Lehr ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Addition Reaction ◽  
Protecting Group ◽  
Human Breast ◽  
Lung Cancer Cell ◽  
Subsequent Removal ◽  
Anticancer Properties ◽  
Tributyltin Hydride ◽  
High Yields

A series of 2-deoxy-2-iodo-α-d-mannopyranosylbenzotriazoles was synthesized using the benzyl, 4,6-benzylidene and acetyl protected D-glucal in the presence of N-iodosuccinimide (NIS). Subsequent removal of the iodine at the C-2 position using tributyltin hydride under free radical conditions afforded the 2-deoxy-α-d-glucopyranosylbenzotriazoles in moderate to high yields. This method was extended to the preparation of substituted 2-deoxy-β-d-glucopyranosylimidazoles as well. The stereoselectivity of the addition reaction and the effect of the protecting group and temperature on anomer distribution of the benzotriazole series were also investigated. The anticancer properties of the newly synthesized compounds were evaluated in a series of viability studies using HeLa (human cervical adenocarcinoma), human breast and lung cancer cell lines. The N-[3,4,6-tri-O-benzyl-2-deoxy-α-d-glucopyranosyl]-1H-benzotriazole and the N-[3,4,6-tri-O-acetyl-2-deoxy-α-d-glucopyranosyl]-2H-benzotriazole were found to be the most potent cancer cell inhibitors at 20 µM concentrations across all four cell lines.

scholarly journals Recoverable Phospha-Michael Additions Catalyzed by a 4-N,N-Dimethylaminopyridinium Saccharinate Salt or a Fluorous Long-Chained Pyridine: Two Types of Reusable Base Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1159
Author(s):  
Eskedar Tessema ◽  
Vijayanath Elakkat ◽  
Chiao-Fan Chiu ◽  
Jing-Hung Zheng ◽  
Ka Long Chan ◽  
...  
Keyword(s):  
Michael Addition ◽  
Polar Solvent ◽  
Addition Reaction ◽  
High Yield ◽  
Addition Reactions ◽  
Polar Solvents ◽  
Unsaturated Bond ◽  
Base Catalysts ◽  
Michael Additions

Phospha-Michael addition, which is the addition reaction of a phosphorus-based nucleophile to an acceptor-substituted unsaturated bond, certainly represents one of the most versatile and powerful tools for the formation of P-C bonds, since many different electrophiles and P nucleophiles can be combined with each other. This offers the possibility to access many diversely functionalized products. In this work, two kinds of basic pyridine-based organo-catalysts were used to efficiently catalyze phospha-Michael addition reactions, the 4-N,N-dimethylaminopyridinium saccharinate (DMAP·Hsac) salt and a fluorous long-chained pyridine (4-Rf-CH2OCH2-py, where Rf = C11F23). These catalysts have been synthesized and characterized by Lu’s group. The phospha-Michael addition of diisopropyl, dimethyl or triethyl phosphites to α, β-unsaturated malonates in the presence of those catalysts showed very good reactivity with high yield at 80–100 °C in 1–4.5 h with high catalytic recovery and reusability. With regard to significant catalytic recovery, sometimes more than eight cycles were observed for DMAP·Hsac adduct by using non-polar solvents (e.g., ether) to precipitate out the catalyst. In the case of the fluorous long-chained pyridine, the thermomorphic method was used to efficiently recover the catalyst for eight cycles in all the reactions. Thus, the easy separation of the catalysts from the products revealed the outstanding efficacy of our systems. To our knowledge, these are good examples of the application of recoverable organo-catalysts to the DMAP·Hsac adduct by using non-polar solvent and a fluorous long-chained pyridine under the thermomorphic mode in phospha-Michael addition reactions.

scholarly journals Synthesis of Network Polymers by Means of Addition Reactions of Multifunctional-Amine and Poly(ethylene glycol) Diglycidyl Ether or Diacrylate Compounds

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2047
Author(s):  
Naofumi Naga ◽  
Mitsusuke Sato ◽  
Kensuke Mori ◽  
Hassan Nageh ◽  
Tamaki Nakano
Keyword(s):  
Ethylene Glycol ◽  
Room Temperature ◽  
Addition Reaction ◽  
Monomer Concentration ◽  
Diglycidyl Ether ◽  
Porous Polymers ◽  
Addition Reactions ◽  
Poly Ethylene Glycol ◽  
Network Polymers ◽  
Poly Ethylene

Addition reactions of multi-functional amine, polyethylene imine (PEI) or diethylenetriamine (DETA), and poly(ethylene glycol) diglycidyl ether (PEGDE) or poly(ethylene glycol) diacrylate (PEGDA), have been investigated to obtain network polymers in H2O, dimethyl sulfoxide (DMSO), and ethanol (EtOH). Ring opening addition reaction of the multi-functional amine and PEGDE in H2O at room temperature or in DMSO at 90 °C using triphenylphosphine as a catalyst yielded gels. Aza-Michael addition reaction of the multi-functional amine and PEGDA in DMSO or EtOH at room temperature also yielded corresponding gels. Compression test of the gels obtained with PEI showed higher Young’s modulus than those with DETA. The reactions of the multi-functional amine and low molecular weight PEGDA in EtOH under the specific conditions yielded porous polymers induced by phase separation during the network formation. The morphology of the porous polymers could be controlled by the reaction conditions, especially monomer concentration and feed ratio of the multi-functional amine to PEGDA of the reaction system. The porous structure was formed by connected spheres or a co-continuous monolithic structure. The porous polymers were unbreakable by compression, and their Young’s modulus increased with the increase in the monomer concentration of the reaction systems. The porous polymers absorbed various solvents derived from high affinity between the polyethylene glycol units in the network structure and the solvents.

Tandem Alkylation/Michael Addition Reaction of Dithiocarbamic Acids with Alkyl γ-Bromocrotonates: Access to Functionalized 1,3-Thiazolidine-2-thiones

Synthesis ◽  
2021 ◽  
Author(s):  
Azim Ziyaei Halimehjani ◽  
Petr Beier ◽  
Maryam Khalili Foumeshi ◽  
Ali Alaei ◽  
Blanka Klepetářová
Keyword(s):  
Amino Acids ◽  
Carbon Disulfide ◽  
Multicomponent Reaction ◽  
Michael Addition ◽  
Addition Reaction ◽  
Primary Amines ◽  
Oxidation Reactions ◽  
Michael Addition Reaction ◽  
Synthetic Utility ◽  
Reaction Proceeds

AbstractThiazolidine-2-thiones were prepared via a novel multicomponent reaction of primary amines (amino acids), carbon disulfide, and γ-bromocrotonates. The reaction proceeds via a domino alkylation/intramolecular Michael addition to provide the corresponding thiazolidine-2-thiones in high to excellent yields. By using diamines in this protocol, bis(thiazolidine-2-thiones) derivatives were synthesized. The synthetic utility of the adducts was demonstrated by hydrolysis, amidation, and oxidation reactions.

Comparative QSAR evidence for a free-radical mechanism of phenol-induced toxicity

2000 ◽  
Vol 127 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Corwin Hansch ◽  
Susan C. McKarns ◽  
Carr J. Smith ◽  
David J. Doolittle
Keyword(s):  
Free Radical ◽  
Radical Mechanism ◽  
Free Radical Mechanism
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