1199357-22-6Relevant academic research and scientific papers
Iridium-catalysed hydrosilylation of cyclopropanes: Via regioselective carbon-carbon bond cleavage
Murai, Masahito,Nishiyama, Atsushi,Nishinaka, Naoki,Morita, Haruka,Takai, Kazuhiko
, p. 9281 - 9284 (2017)
While cyclopropanes have been explored as synthetically valuable building blocks, their transformation without conjugated substituents or directly substituted heteroatoms remains challenging. The current study describes the iridium-catalysed ring-opening hydrosilylation of cyclopropanes. A nitrogen-based directing group was found to control the reactivity of iridium active species as well as the regiochemistry of carbon-carbon bond cleavage and hydrosilylation.
Limits on the transition state geometry for metal insertion into a carbon-hydrogen bond
Suggs, J.William,Pearson
, p. 3853 - 3856 (1980)
Using chelating ligands to fix the position of the metal and CH bond, evidence is found which favors a triangular geometry for metal insertion.
Reactions of 1,2,4-Oxadiazole[4,5-a]piridinium Salts with Alcohols: the Synthesis of Alkoxybutadienyl 1,2,4-Oxadiazoles
Moiola, Mattia,Leusciatti, Marco,Quadrelli, Paolo
, p. 195 - 199 (2020)
1,2,4-Oxadiazole[4,5-a]piridinium salts add alcohols and alkoxides to undergo electrocyclic ring opening affording alkoxybutadienyl 1,2,4-oxadiazole derivatives. The pyridinium salts represent a special class of Zincke salts that are prone to rearrange to give alkoxybutadienyl 1,2,4-oxadiazoles when treated with suitable nucleophiles or, alternatively, to give pyridones in the presence of bicarbonate. The pivotal tuning of the experimental conditions leads to a straightforward synthesis of valuable 1,2,4-oxadiazole derivatives. The mechanism is also discussed in the light of previous observations.
Thione-Disulfide Interchange of some Heterocyclic Tautomeric Thiones and their Symmetrical Bisulfides
Stoyanov,Stoyanova,Antonov,Karagiannidis,Akrivos
, p. 495 - 504 (1996)
The UV/Vis spectroscopic properties of some symmetrical disulfides derived from potentially tautomeric thiones are investigated. Reversed thione-disulfide transformation is observed, and the influence of several factors including the nature of solvent, concentration, and UV irradiation, is studied. Possible implication of the tautomeric thiol form and the importance of this thione-disulfide redox system in biological aspects is suggested. A general scheme including monomer-dimer equilibrium, thione-thiol tautomeric equilibrium, and reversible thiol-disulfide redox behaviour is proposed in order to explain the factors affecting the overall thione-disulfide transformation.
Photoinduced heterolysis of the carbon-oxygen bond in bichromophoric 1- arylmethyloxy-2-pyridones
Sakurai, Tadamitsu,Kubo, Kanji,Kojima, Shunsuke,Shoro, Takuya,Inoue, Hiroyasu
, p. 9747 - 9750 (1998)
Irradiation of the title compound having a 9-anthryl (1a) or a 1- pyrenyl group (1b) in methanol was found to give the heterolytic C-O bond cleavage products: 1-hydroxy-2-pyridone and arylmethyl methyl ether, (which predominate for the reaction of 1a), along with 2-pyridone, aryl-substituted methanol and aryl aldehyde derived from the homolysis of the N-O bond (that mainly occurs in the photolysis of 1b). Spectroscopic analysis of the ground- state and excited singlet-state behavior of 1 revealed that a non-emissive intramolecular exciplex (whose formation rate is much faster in 1a than in 1b) plays a key role in inducing the C-O bond heterolysis.
THREE-STEP SYNTHESIS OF 4-(2'-HYDROXYETHYL)AZETIDIN-2-ONE AND ITS SUBSTITUTED DERIVATIVES FROM 4-ACETOXY-2-PYRIDONES
Kaneko, Chikara,Naito, Toshihiko,Saito, Akemi
, p. 1591 - 1594 (1984)
4-(2'-Hydroxyethyl)azetidin-2-one, an important synthetic intermediate for carbapenem, and its substituted derivatives have been synthesized from 4-acetoxy-2-pyridones by photolysis, catalytic hydrogenation, followed by basic hydrolysis in the presence of sodium borohydride.
Kinetics and products of the TiO2 photocatalytic degradation of pyridine in water
Maillard-Dupuy,Guillard,Courbon,Pichat
, p. 2176 - 2183 (1994)
Pyridine (Pyr), a noxious chemical whose ring is part of the chemical structure of many pesticides, is more rapidly eliminated in water by photocatalysis over TiO2 than benzamide, whose nucleus has also a relatively low electron density and whose extent of adsorption is equivalent. Hydroxylation of Pyr first occurs only at position 2. Beside acetate and formate, whose formation from Pyr is derived from ion chromatography analysis, seven aliphatic intermediates with one to five C atoms are identified by GC-MS. They all contain one or several C=O groups, and wherever the N atom subsists, it is as an amide, i.e., with an unchanged oxidation number. For relatively high initial Pyr concentrations (16.5 mmol/L), dipyridyl and carbamoyl pyridine isomers are also detected as intermediates, at much lower concentrations, however, than that of 2-hydroxypyridine; this shows the existence of coupling reactions. Within an UV irradiation period about 2.5 times as long as that necessary to eliminate Pyr, organic nitrogen is almost entirely mineralized, mainly into NH4+ ions that are very slowly oxidized to nitrate.
Pressure Tuning of Chemical Reaction Equilibria in Supercritical Fluids
Peck, Douglas G.,Mehta, Anil J.,Johnston, Keith P.
, p. 4297 - 4304 (1989)
Supercritical fluid solvent effects were studied for the tautomeric equilibria of 2-hydroxypyridine and 2-pyridone at infinite dilution, both experimentally and theoretically.The fluids were propane at 393 K and 1,1-difluoroethane at 403 K, and pressures ranged from 21 to 206 bar.The equilibrium constant, Kc, which was measured by in situ UV spectroscopy, increased 4-fold a pressure increase of 400 bar in 1,1-difluoroethane, with a partial molar volume change on reaction reaching -1400 cm3/mol.A thermodynamic model was developed to increase the range of pressures studied and to explore temperature effects.The tuning of chemical reaction equilibria is a powerful technique for charaterizing a key advantage of supercritical fluid solvents, wich is their enormous adjustabilyty.
EQUILIBRE LACTIME-LACTAME DES HYDROXY-PYRIDINES ET DES HYDROXY-PYRIMIDINES (URACILES) EN MILIEU APOLAIRE: ETUDE INFRA-ROUGE
Chevrier, Marianne,Bensaude, Olivier,Guillerez, Jean,Dubois, Jacques-Emile
, p. 3359 - 3362 (1980)
In contrast to what observed with mono hydroxy-pyridines and -pyrimidines the lactim-lactam equilibrium of uracils is not found to be markedly influenced by solvent polarity.
Simple Oxidations of Pyridines: Zinc Sulphates or Natural Sand as Remarkably Specific Catalysts
Gillard, R. D.,Hall, D. P. J.
, p. 1163 - 1164 (1988)
The clean oxidations in reasonable yields of pyridine to 4,4'-bipyridyl (catalysed by sand) and of pyridines to their 2-pyridones using zinc sulphate are described.
