Showing papers on "Cyclohexene published in 1986"
TL;DR: Infrared spectra of the unreacted dideuterioethylenes indicate that they do not isomerize under the conditions of the reaction, and theoretical evidence for the synchronicity of this concerted mechanism is reported.
Abstract: Diels-Alder reactions of substituted dienes and dienophiles have been found to cccur by both concerted and stepwise mechanisms.’.* The nature of the mechanism of the prototype Diels-Alder reaction of butadiene with ethylene to form cyclohexene is not only of fundamental interest but has generated fervid fulminations for favorite We wish to report new experimental evidence that is compatible only with the concerted mechanism, as well as further theoretical evidence for the synchronicity of this concerted mechanism.6 The reactions of 1,1,4,4-tetradeuterio-1,3-butadiene with cisor trans-1,2-dideuterioethylene were carried out at 185 “ C for 36 h at a pressure of 1800 psi in a stainless steel b~mb.~-’O Infrared spectra of the unreacted dideuterioethylenes indicate that they do not isomerize under the conditions of the reaction. Each cyclohexene product was separated from butadiene dimers by preparative GLC” and was then epoxidized with m-chloroperbenzoic acid (Figure 1). The N M R spectrum of cyclohexene oxide (Figure 2A) has resonances for the protons at C, and C, at 6 1.19 and 1.38, corresponding to protons that are cis and trans to the epoxide oxygen.12 The proton NMR spectra of the epoxides obtained from the reactions of cis and trans-dideuterioethylenes are clearly different. The DH couplings were partially eliminated by irradiation of the C3 and C6 deuteriums to give the spectra shown in Figure 2. The cis-dideuterio compound has a singlet resonance at d 1.19, due to the product with C4 and Cs hydrogens cis to the epoxide, and a second singlet a t 6 1.38, due to the
133 citations
TL;DR: In this article, the acidity of supported PbO catalysts affects the selectivity of the oxidative coupling of methane to C2+ hydrocarbons: the higher the catalyst acidity the lower the C 2+ selectivity.
89 citations
88 citations
TL;DR: In this article, two concurrent processes have been identified with cyclohexene as the olefinic substrate, which affords both cycloenyl t-butyl peroxide and cycloenene oxide within 5 min at 25 °C in acetonitrile solutions.
87 citations
TL;DR: In this article, the Co 2 CO 8 -Ru 3 (CO) 12 bimetallic systems showed high catalytic activity for hydroformylation of olefins such as cyclohexene, 1-hexene and styrene.
70 citations
TL;DR: In this article, the influence of potassium nitrate addition to Ni SiO 2 catalysts on the kinetic parameters of various reactions (ethane and propane hydrogenolysis, D2CH4 exchange, benzene and CO hydrogenations) has been investigated.
69 citations
55 citations
TL;DR: In this article, a series of NiMo catalysts prepared on aluminas modified by different ions (F, Cl, SO4, Zn, Mg, Na) were examined from the point of view of three functions: hydrodesulphurization, hydrogenation and isomerization.
52 citations
48 citations
TL;DR: In this paper, the cyclization of a bromovinyl-type appendage onto a functionalized cyclohexene carboxylic acid derivative produces the corresponding oxahydrindanes which can be transformed into hexahydrinenes (hexahydrobenzofurans) related to the title compounds.
48 citations
TL;DR: In this paper, the porphyrines de Mn(III) were used to synthesize cyclohexene and styrene catalysees, and they were also used for methyl-1 cyclo-hexene.
Abstract: Epoxydations du cyclohexene, du methyl-1 cyclohexene et du styrene catalysees par des porphyrines de Mn(III)
TL;DR: In this paper, the authors show that conjugated nitroalkenes (1b, 5b) with sodium nitrite and iodine in ethyl acetate (or ether) and water in the presence of ethylene glycol (or propylene gels) can be obtained in 49-82% yields.
Abstract: Treatment of alkenes (1a–5a) with sodium nitrite and iodine in ethyl acetate (or ether) and water in the presence of ethylene glycol (or propylene glycol) provides conjugated nitroalkenes (1b–5b) in 49–82% yields.
TL;DR: Les acidites en phase gazeuse de quelques alcenes et dienes mono-and bicycliques sont mesurees dans une etude modele de l'homoaromaticite anionique as mentioned in this paper.
Abstract: Les acidites en phase gazeuse de quelques alcenes et dienes mono- et bicycliques sont mesurees dans une etude modele de l'homoaromaticite anionique
Patent•
18 Jun 1986
TL;DR: In this article, an epoxy resin composition which is liquid and can be used in an extremely cold area, does not generate precipitate even if left for a long period and has excellent preserving stability comprising an expoxy resin and a specific liquid acid anhydride type hardening agent is presented.
Abstract: PURPOSE:To provide an epoxy resin composition which is liquid and can be used in an extremely cold area, does not generate precipitate even if left for a long period and has excellent preserving stability comprising an expoxy resin and a specific liquid acid anhydride type hardening agent CONSTITUTION:An epoxy resin (A) having one or more epoxy groups per one molecule, and an acid anhydride type hardening agent (B) being liquid at below -30 degC comprising 80-50wt% of a liquid stereoisomer mixture (a) with mp of below 20 degC obtained by a method wherein cis-3-methyl-4-cyclohexene-cis, cis-1,2- dicarboxylic acid anhydride is subjected to heat treatment at 180-300 degC in the presence or the absence of a catalyst and isomerized stereochemically and 20-50 wt% of a liquid structural isomer mixture (b) with mp of below 45 degC obtained by a method wherein 4-methyl-4-cyclohexene-1,2-dicarboxylic acid anhydride is subjected to heat treatment at 50-250 degC in the presence of a catalyst to transfer double bond of cyclohexene ring are mixed such that the number of acid anhydride groups is 05-15per epoxy group
TL;DR: In this article, the texture of AlPO/sub 4/ treated at different temperatures (770-1270 K) and impregnated with fluoride ions (1-3 wt%) as well as their catalytic activities for the cyclohexene skeletal isomerization were investigated.
TL;DR: In this paper, the photochimie de l'α-diazotoluene dans le cyclohexene-D 10 and dans l'cyclohexane-D 12 was studied.
Abstract: On etudie la photochimie de l'α-diazotoluene dans le cyclohexene-D 10 et dans le cyclohexane-D 12 . Les resultats sont en accord avec des reactions du phenylcarbene a l'etat singulet. On observe un effet isotopique faible pour l'insertion du CH a 25°C; cet effet croit par refroidissement. Le refroidissement a tres basse temperature (−196°C) reduit l'effet isotopique
TL;DR: In this article, small platinum particles of colloidal size (50 - 60 A) are readily obtained by reducing K 2 PtCl 4, entrapped in polymerized vesicles, by means of UV irradiation.
TL;DR: In this paper, the results of prehydrogenated coordinated polymer matrices revealed effective heterogeneous catalysis with respect to initial rates and selectivity under mild experimental conditions, and showed that matrix reduction to metallic particles under the conditions of the catalytic hydrogenation experiments does not seem likely.
TL;DR: In this article, the X-ray crystal structure of periplanone-B is presented, which is a cyclodecadienone-based approach to the ten-membered ring.
TL;DR: Synthese par addition du chlorure de benzenesulfenyle a des cyclohexene, methyl-2 butene-3ol-2, phenyl-2propene, decene-1 en presence de fluorure d'argent.
Abstract: Synthese par addition du chlorure de benzenesulfenyle a des cyclohexene, methyl-2 butene-3ol-2, phenyl-2propene, decene-1 en presence de fluorure d'argent
TL;DR: In this paper, the transformation of Et3SiH occurring with CSi bond breaking was studied on CabO OSilsupported Cu, Ni, Rh, Pd, and Pt catalysts by the pulse technique in H2 and He at 473-673 K. The poisoning effect of the surface silicon residues was found to be different for the hydrogenation of propene, cyclohexene, and benzene and for the dehydrogenation of 2-propanol and cycloencene.
TL;DR: In this paper, a multi-stage radical-cation mechanism is proposed, in which an initial reversible protonation is followed by an electron transfer stage (rate-determining), and the cation-radical thus produced, adds rapidly an additional ClO2 to form dioxygenated products.
Abstract: The kinetics and product studies of oxidation of eight olefins 1-8 by ClO2 in H2O in the pH range 3-7 are described. The reaction is faster as the pH decreases. At pH < 4, ClO2 reacts equimolarly with olefins to yield isomeric mixtures of chlorohydrines and 1,2-dioxygenated products, following the equation:
The order of reactivity is: (E)-stilbene > indene > β-methylstyrene > acenaphthylene > α-methylstyrene > styrene > cyclohexene > allylbenzene. A multi-stage radical-cation mechanism is proposed, in which an initial reversible protonation:
is followed by an electron-transfer stage (rate-determining):
The cation-radical thus produced, adds rapidly an additional ClO2 to form dioxygenated products. The chlorohydrines most likely arise from HClO additions to the olefinic double bonds, which, in turn, generate from dismutation of 2 HClO2 into HClO + H+ + ClO.
TL;DR: In this article, an inverse relationship is found between the enthalpy of formation ΔH0 of the dihydrido complexes and activation ΔH≠ of the hydrogenation step.
TL;DR: The reaction of N,N′-bis(2′-pyridinecarboxamide)-1,2-benzene (bpbH2) with K2[OsO2(OH)4] yielded trans-[OsVI(bpb H2)O2]2+ which in turn gave trans[OsIII( bpb H 2 )Cl] upon treatment with PPh3; the OsIII complex has been characterized by X-ray crystallography and found to catalyse the epoxidation of cyclohexene in the presence of iod
Abstract: The reaction of N,N′-bis(2′-pyridinecarboxamide)-1,2-benzene (bpbH2) with K2[OsO2(OH)4] yielded trans-[OsVI(bpbH2)O2]2+ which in turn gave trans-[OsIII(bpb)(PPh3)Cl] upon treatment with PPh3; the OsIII complex has been characterized by X-ray crystallography and found to catalyse the epoxidation of cyclohexene in the presence of iodosobenzene.