93624-01-2Relevant articles and documents
α-Xanthylmethyl Ketones from α-Diazo ketones
López-Mendoza, Pedro,Miranda, Luis D.
, p. 3777 - 3790 (2021/07/07)
A simple and efficient method to obtain α-xanthylmethyl ketones from α-diazo ketones is described. The reaction proceeds through a protonation/nucleophilic substitution sequence in the presence of p -toluenesulfonic acid and potassium ethyl xanthogenate as the nucleophile. As α-diazo ketones can be readily synthesized from ubiquitous carboxylic acids, a broad variety of xanthates can be obtained, including examples from naturally occurring substrates.
Electrochemical reactivity of S-phenacyl-O-ethyl-xanthates in hydroalcoholic (MeOH/H2O 4:1) and anhydrous acetonitrile media
López-López, Ernesto Emmanuel,López-Jiménez, Sergio J.,Barroso-Flores, Joaquín,Rodríguez-Cárdenas, Esdrey,Tapia-Tapia, Melina,López-Téllez, Gustavo,Miranda, Luis D.,Frontana-Uribe, Bernardo A.
, (2021/04/12)
The electrochemical behavior of a series of S-phenacyl-O-ethyl-xanthates (O-ethyl-dithiocarbonate acetophenone derivatives) in hydroalcoholic (MeOH/H2O 4:1) and anhydrous media (ACN/TBAPF6) using carbon electrodes was studied. Cyclic voltammetry showed in hydroalcoholic media only two cathodic waves, whereas in ACN one anodic and two cathodic waves were present. The first cathodic wave corresponded to the reduction of the phenylketone group, whereas the first anodic was attributed to the xanthate unit. Macroelectrolysis on graphite and vitreous carbon at anodic and cathodic potentials, let us to explore the synthetic potential of this electrochemical reactions. With some compounds in hydroalcoholic media and using carbon electrodes, polymeric material was deposited on the electrode impeding the reaction; this deposit was characterized by AFM and SEM-EDS. The electroreduction on Ti electrode overcome this problem and gave the corresponding acetophenones (>95%). On the other hand, in ACN, small quantities of the dimeric 1,4-dicarbonyl compounds X-PhCOCH2CH2COPh-X (7–15%), as well as the corresponding acetophenones (ca. 50%) were isolated. Oxidation macroelectrolysis showed a very complicated transformation without synthetic value. The reaction mechanism for the reduction and the homolytic dissociation into the phenacyl radical was supported by DFT calculations.
Synthesis of pyrazolylvinyl ketones from furan derivatives
Sawengngen, Nattawut,Chalikidi, Petrakis N.,Araby, Sara,Hampel, Frank,Gmeiner, Peter,Serdyuk, Olga V.
supporting information, p. 4850 - 4855 (2019/05/24)
A new protocol for the synthesis of pyrazol-5-ylvinyl ketones, e.g. pyrazole-chalcones, employing furfuryl ketones as a triketone equivalent, has been developed. The reaction occurs under mild conditions and does not require the use of expensive materials
A simple method for the synthesis of furfuryl ketones and furylacetic acid derivatives
Chalikidi, Petrakis N.,Nevolina, Tatyana A.,Uchuskin, Maxim G.,Abaev, Vladimir T.,Butin, Alexander V.
, p. 621 - 629 (2015/10/12)
A simple preparative method has been developed for the synthesis of aryl(furfuryl) ketones, amides, and furylacetic acid esters, based on radical alkylation of furan derivatives at the α-position with O-ethyl(phenacyl)xanthogenates and phenacyl iodides in the presence of Fenton's reagent (H2O2/FeSO4·7H2O) in DMSO. The range of applicability and mechanisms for the formation of major and side products have been considered.
Flexible routes to thiophenes
Jullien, Helene,Quiclet-Sire, Beatrice,Tetart, Thomas,Zard, Samir Z.
supporting information, p. 302 - 305 (2014/01/23)
Three convergent routes to thiophenes are described, hinging on the radical addition of α-xanthyl ketones to ethyl vinyl sulfide or to vinyl pivalate. The latter route ultimately proved to be the most versatile and efficient (61-94%).
One-pot synthesis of symmetric 1,7-dicarbonyl compounds via a tandem radical addition-elimination-addition reaction
Huang, Zhongyan,Xu, Jiaxi
, p. 15114 - 15120 (2013/09/02)
A novel approach to synthesize symmetric 1,7-dicarbonyl compounds via a tandem radical addition-elimination-addition reaction of S-carbonylmethyl xanthates with allylmethylsulfone and its analogues has been developed. Radicals were produced from S-carbonylmethyl xanthates by adding dilauroyl peroxide and reacted with allylmethylsulfone or analogues to generate terminal olefins as intermediates. The excessive radicals reacted with the intermediate olefins immediately to give adducts of symmetric 1,7-dicarbonyl compounds. This is an efficient method to synthesize 1,7-dicarbonyl compounds under mild conditions. The Royal Society of Chemistry 2013.
A convergent approach to polycyclic aromatic hydrocarbons
Guignard, Raphael F.,Zard, Samir Z.
supporting information; experimental part, p. 12185 - 12187 (2011/12/15)
A new concise route to Polycyclic Aromatic Hydrocarbons (PAHs) through radical addition and cyclisation of xanthates is described. The Royal Society of Chemistry 2011.
Photochemistry of S -phenacyl xanthates
Tazhe Veetil, Aneesh,Solomek, Tomas,Ngoy, Bokolombe Pitchou,Pavlikova, Nela,Heger, Dominik,Klan, Petr
experimental part, p. 8232 - 8242 (2012/01/03)
Various synthetically readily accessible S-phenacyl xanthates are shown to undergo photoinitiated homolytic scission of the C-S bond in the primary step. The resultant fragments, phenacyl and xanthic acid radicals, recombine to form symmetrical 1,4-diketones and xanthogen disulfides, respectively, in high to moderate chemical yields in chemically inert solvents. They can also be efficiently trapped by a hydrogen-atom-donating solvent to give acetophenone and xanthic acid derivatives. The latter compound is in situ thermally converted to the corresponding alcohol in high chemical yields. S-Phenacyl xanthates could thus be utilized as synthetic precursors to the above-mentioned compounds or as photoremovable protecting groups for alcohols in which the xanthate moiety represents a photolabile linker. The photochemically released phenacyl radical fragments efficiently but reversibly add to the thiocarbonyl group of the parent xanthate molecule. The kinetics of this degenerative reversible addition-fragmentation transfer (RAFT)/macromolecular design via the interchange of xanthates (MADIX) mechanism was studied using laser flash photolysis (LFP) and density functional theory (DFT) calculations. The rate constants of the RAFT addition step, kadd ～ 7 × 108 M-1 s-1, and phenacyl radical addition to a double bond of 1,1-diphenylethylene, kadd ～ 108 M-1 s -1, in acetonitrile were experimentally determined by LFP. In addition, photoinitiation of the methyl methacrylate polymerization by S-phenacyl xanthate is demonstrated. The polydispersity index of the resulting poly(methyl methacrylate) was found to be ～1.4. We conclude that S-phenacyl xanthates can serve simultaneously as photoinitiators as well as RAFT/MADIX agents in polymerization reactions.
An expedient, flexible and convergent access to selectively protected 1,5-dicarbonyl compounds. Applications to the synthesis of 2,6-disubstituted pyridines and thiopyridines
Boivin, Jean,Carpentier, Floriane,Jrad, Rafik
, p. 1664 - 1672 (2007/10/03)
Intermolecular addition of 2-oxoalkyl radicals generated from the corresponding S-alkyl-O-ethyl dithiocarbonates on vinyl ketals afforded selectively protected 1,5-dicarbonyl compounds in good yields. These key-intermediates can be converted into a plethora of useful substances. Transformations to pyridines and thiopyridines were given as examples. Georg Thieme Verlag Stuttgart.
