1630-94-0Relevant academic research and scientific papers
Solvent perturbs the reactivity of tert-butylcarbene
Ruck, Rebecca T.,Jones Jr., Maltland
, p. 2277 - 2280 (1998)
Two different sources of tert-butylcarbene are used to generate this reactive intermediate in a variety of solvents. Two products, 1,1- dimethylcyclopropane and 2-methyl-2-butene are formed. Solvents able to form an ylid or complex with the carbene strongly favor the alkene product.
tert-BUTYLCARBENE FROM 1,1-DIIODONEOPENTANE
Fukushima, Motoo,Jones, Maitland,Brinker, Udo H.
, p. 3211 - 3214 (1982)
When 1,1-diiodoneopentane is passed through a hot tube containing methyllithium-coated Pyrex chips, 1,1-dimethylcyclopropane and 2-methyl-2-butene are produced in near quantitative yield.The ratio of products indicates that the intermediate carbene is the same as is produced from thermal or photosensitized decomposition of tert-butyldiazomethane but different from that formed by direct irradiation of the diazo compound.
Generation of methylene by the liquid phase oxidation of isobutene with nitrous oxide
Semikolenov, Sergey,Ivanov, Dmitry,Babushkin, Dmitry,Malykhin, Sergey,Kharitonov, Alexander,Dubkov, Konstantin
, p. 3589 - 3595 (2018)
The application of nitrous oxide as an alternative oxidant provides new opportunities for selective oxidation of olefins. Here, we studied for the first time the thermal oxidation of isobutene with N2O in the liquid phase. The study revealed that the oxidation proceeds via 1,3-dipolar cycloaddition of N2O to the C[dbnd]C bond by two routes forming unstable 4,5-dihydro-[1,2,3]-oxadiazole intermediates. The main route (the contribution of 91%) includes the addition of the N2O oxygen to the second carbon atom in olefin. In this case, the oxadiazole decomposes with the C–C bond cleavage yielding acetone, methylene (:CH2), and N2. The methylene then readily reacts with isobutene and benzene (solvent). The minor route involves the addition of the N2O oxygen to the first carbon atom and the oxadiazole decomposition with a hydrogen shift leading to isobutanal and N2. The main distinctive feature of the studied reaction is the formation of methylene in high yield.
Azo-coupling and reduction of cyclopropanediazonium ions in the reactions with polyhydroxyarenes and aminophenols
Shulishov,Klimenko,Korolev,Kostyuchenko,Okonnishnikova,Tomilov
experimental part, p. 1703 - 1711 (2011/04/23)
A reaction of cyclopropanediazonium ion, generated by decomposition of N-cyclopropyl-N-nitrosourea upon treatment with potassium or cesium carbonates, with various poly-hydroxyarenes and aminophenols has been studied. The reaction of azo-coupling proceeds with phloroglucinol, resorcinol, 3-methoxy- and 3-aminophenol giving rise to mono-, bis-, and tris(cyclopropylazo)arenes as the major products. Oxidizable phenols such as hydro-quinone, 2-methoxy-, 4-amino-, and 2-aminophenol give products of radical transformations with participation of cyclopropyl radical.
Rate coefficients of hydroxyl radical reaction with dimethyl ether and methyl tert-butyl ether over an extended temperature range
Arif,Dellinger,Taylor
, p. 2436 - 2441 (2007/10/03)
Rate coefficients of the reaction of hydroxyl (OH) radicals with CH3OCH3 (k1) and CH3OC(CH3)3 (k2) over an extended temperature range are reported. Measurements were performed using a laser photolysis-laser-induced fluorescence technique under slow flow conditions at a total pressure of 740±10 Torr. Arrhenius plots of the data exhibited significant curvature and were fitted in the form of k(T) = ATB exp(-C/T). The resulting modified Arrhenius expressions (error limits ±2σ) that best described these extended temperature measurements and prior low-temperature measurements were (in units of cm3 molecule-1 s-1) k1(295-650 K) = (1.05±0.10)×10-17T2.0 and exp[(328±32)/T] and k2(293-750 K) = (1.15±0.11)×10-17T2.04 exp-[(266±41)/T]. Comparison of our measurements for k1 with previous, overlapping low-temperature measurements indicated generally good agreement. Our measurements for k2, although consistent with previous room temperature measurements, exhibited a larger temperature dependence than previously reported. High-temperature oxidation mechanisms for these oxygenated fuel components are proposed. Support for the mechanisms is presented in the form of product analysis studies in high-temperature tubular flow reactors. For CH3OC(CH3)3, these studies suggest that H abstraction from the tert-butyl group is an important high-temperature oxidation pathway.
A Photochemical Source of Real Alkylcarbenes
Glick, HC,Likhotvorik, Igor R.,Jones, Maitland
, p. 5715 - 5718 (2007/10/02)
Treatment of 7,7-dibromodibenzobicycloheptane with di-tert-butylcuprate or dibutylcuprate, followed by quenching with water, led to exo- and endo-7-monoalkyldibenzobicycloheptanes.Photolysis through either quartz or Pyrex gave the products of intramolecular reactions of the corresponding alkylcarbenes.The temperature dependence of the products formed from tert-butylcarbene was verified, and butylcarbene was trapped intermolecularly. - Keywords: carbenes, retrocycloadditions, insertion reactions.
Synthesis, structure, and reactions of heterobinuclear μ-methylene complexes
Mackenzie, Peter B.,Coots, Robert J.,Grubbs, Robert H.
, p. 8 - 14 (2008/10/08)
Sources of the reactive fragment Cp2Ti==CH2 react with a variety of late-transition-metal complexes containing μ-halides [Cl-MLn]2 to yield early-late binuclear complexes containing μ-CH2, and μ-Cl ligands. Complexes containing Rh, Ir, Pt, Pd, and Au have been prepared and characterized. The X-ray structure of the complex Cp2Ti-CH2-RhCl(COD) (COD = 1,5-cyclooctadiene) prepared from Cp2Ti-CH2C-(CH3)2-CH2 and [Cl-Rh(COD)]2 has been determined. Crystallographic data: space group Pbcm; Z = 4; a = 8.268 (2) A?, b = 16.409 (4) A?, c = 12.604 (3) A?; V = 1710 (1) A?3. The structure was refined to a final R of 0.069 and R3σ of 0.048 for the 1061 reflections that had Fo > 3σ(Fo).
Preparation and properties of metallacyclobutanes of nickel and palladium
Miyashita, Akira,Ohyoshi, Mayumi,Shitara, Hiroaki,Nohira, Hiroyuki
, p. 103 - 112 (2007/10/02)
Bis(phosphine)-3,3-dimethylnickela- and palladacyclobutanes have been prepared by intramolecular C-H insertion reaction of the corresponding dineopentyl metal complexes.Nickelacyclobutane complexes decompose when heated thereby undergoing competitive carb
Synthesis of metallacyclobutanes and metallacyclobutabenzenes of molybdenum and tungsten
Boer, H.J.R. de,Heisteeg, B.J.J. van de,Schat, G.,Akkerman, O.S.,Bickelhaupt, F.
, p. 197 - 200 (2007/10/02)
Reactions of 1,3-bis(bromomagnesio)-2,2-dimethylpropane or 1-magnesacyclobutabenzene with either dichloromolybdenocene or dichlorotungstenocene have given the corresponding four-membered metallacycles of both metals.
Intermolecular activation of C-D bonds in benzene-d6 by trans-neopentyl(trifluoromethanesulfonato)bis(trimethyl-phosphine) platinum (II)
Brainard, Robert L.,Rodger Nutt,Randall Lee,Whitesides, George M.
, p. 2379 - 2386 (2008/10/08)
trans-(Me3P)2Pt(CH2C(CH3) 3)(SO3CF3) (L2PtNpTf, 1) reacts with benzene-d6 at 133°C and gives trans-(Me3P)2Pt(C6D5)(SO 3CF3) (2) and neopentane-d1 as the major products. When this reaction is carried out in concentrated solutions ([1]0 ≥ 0.04 M), small quantities of neopentane-d0 (8-17%) and 1,1-dimethylcyclopropane (1-3%) are also detected; larger quantities of neopentane-d0 are produced (32-45%) when the initial concentration of 1 is low ([1]0 = 0.01-0.03 M). The rate of reaction is decreased by the addition of Bu4N+Tr- and increased by the addition of Bu4N+BF4-. A competitive kinetic isotope effect was estimated by allowing 1 to react with C6D5H and comparing the relative yields of neopentane-d0 and neopentane-d1: kH/kD is large, but its quantitative value is uncertain because of experimental ambiguities. The mechanism for this reaction seems to involve generation of L2PtNp+ as an essential intermediate. This intermediate appears to react with benzene by direct oxidative addition of a C-H bond, but electrophilic attack on the benzene ring cannot be rigorously excluded.
