2808-38-0Relevant academic research and scientific papers
Thermal reaction of cyclic alkadiene with trichlorosilane. Preparative and mechanistic aspects
Jung, Dong Eui,Han, Joon Soo,Yoo, Bok Ryul
, p. 40 - 44 (2013/03/13)
The thermal reactions of trichlorosilane (1a) with cyclic alkadienes such as cyclopentadiene (2a), 1,3-cyclohexadiene (2b), and 1,4-cyclohexadiene (2c) were studied at temperatures ranging from 170 °C to 250 °C. In this reaction, the hydrosilylation rate increased as the reaction temperature was raised using an equimolar ratio of 1a to 2a. The reaction of 2a with 1a at 250 °C afforded 2-cyclopentenyltrichlorosilane (3a) as the major hydrosilylation product within 1 h in good yield (82%). This reaction also works when dicyclopentadiene (2a′) was used as a reactant instead of 2a. In a large scale preparation under the same conditions, 3a was obtained in 82% isolated yield. It is significant to note that 2a′ can be used for the hydrosilylation, with no requirement of a cracking step under our thermal conditions. While the reaction of cyclohexadienes with 1a under the same conditions gave a mixture of three hydrosilylation products such as 2-cyclohexenyltrichlorosilane (3b), 3-cyclohexenyltrichlorosilane (3c) and cyclohexyltrichlorosilane (5) in moderate yields, along with other unsaturated C6 components, such as benzene and cyclohexene. In the thermal reaction of cycloalkadienes with 1a, the five-membered-ring diene 2a undergoes both a hydrosilylation reaction with 1a as well as a [4 + 2] cycloaddition reaction, leading to the hydrosilylation product 3a in good yield. While the six-membered ring dienes, 2b and 2c, undergo four different types of reactions, including hydrosilylation, [4 + 2] cycloaddition, dehydrogenation, and hydrogenation in competition to give the hydrosilylation products, hexane, and benzene, respectively. The reaction rates of cyclic alkadienes under our thermal conditions increase in the following order: 2c 2b 2a.
Bimolecular formation of radicals by hydrogen transfer, 11: Transfer hydrogenation of conjugated cyclic dienes and trienes
Morgenthaler, Jens,Ruechardt, Christoph
, p. 1529 - 1532 (2007/10/03)
1,3-Cyclohexadiene, 1,3-cycloheptadiene and cycloheptatriene are smoothly hydrogenated to cyclohexene and cycloheptene, respectively, when heated to 260-340°C with an excess of 9,10-dihydroanthracene (DHA) in diphenyl ether or benzonitrile. On the basis of a mechanistic study a nonchain three-step mechanism is proposed which is initiated by a transfer of a hydrogen atom from DHA to the polyenes (retrodisproportionation). VCH Verlagsgesellschaft mbH, 1996.
Cycloaddition Reactions Initiated by Photochemically Excited Pyrylium Salts
Martiny, Martin,Steckhan, Eberhard,Esch, Thomas
, p. 1671 - 1682 (2007/10/02)
Several pyrylium, thiapyrylium, and pyridinium salts have been synthesized and used as sensitizers for photochemically induced electron-transfer (PET) reactions.The salts have been tested in the mixed cycloaddition reactions of styrenes 9 with 1,3-cyclohe
Electron Transfer Reactions in Organic Chemistry. XXI. New Catalysts for the Diels-Alder Dimerization of 1,3-Cyclohexadiene: Broensted, Lewis and Redox Catalysts
Eberson, Lennart,Olofsson, Berit,Svensson, Jan-Olof
, p. 1005 - 1015 (2007/10/02)
The dimerization of a model compound, 1,3-cyclohexadiene (CHD), to give the Diels-Alder dimer has been studied with the aim of finding other catalysts than the commonly used tris(4-bromophenyl)aminium ion (TBPA-cation radical).Other radical cations with redox potentials (ArH(cation radical)/ArH) ca. 1.0 V vs.SCE worked equally well.Among inorganic species, iron(III) chloride was a good catalyst and iron(III)(phenanthroline) a slightly less efficient one.In contrast, the strong oxidants, hexachloroosmate(V), tungsten hexachloride and hexanitroacetate(IV) did not sustain DA dimerization but instead produced benzene in low yield.With trifluoroacetic acid as a catalyst, a maximum yield of 15percent of the DA dimer was obtained.There was evidence for formation of a coupling product between tris(4-methoxyphenyl)aminium ion and CHD.In the TBPA(cation radical)-catalyzed reaction, added 'inert' anions, like perchlorate and trifluoromethanesulfonate, almost eliminated DA dimerization.These solutions displayed spectacular color changes; the original blue color of TBPA(cation radical) decayed very fast (seconds) and was later replaced by a new blue color (minutes) which then slowly faded away (hours).A persistent radical species (triplet, showing hyperfine coupling to one nitrogen) was detected in the solutions after the TBPA(cation radical)-catalyzed reactions.
Irradiation of 1,3-Dienes in the Presence of Anilines
Culp, Sandra J.,Bednar, William M.,Pienta, Norbert J.
, p. 3953 - 3955 (2007/10/02)
Acetonitrile solutions of 1,3-cyclohexadiene or 2,5-dimethyl-2,4-hexadiene and aniline, its N-methylated derivatives, Et2NH, or Et3N were irradiated at 350 nm.Adducts (3-anilinoalkenes) were observed in the presence of the primary or secondary anilines but not with the tertiary aniline or the alkylamines.The products are interpreted as arising via an electron-transfer intermediate within the singlet manifold.The cyclic diene gives competitive and dimerization apparently via the triplet.A third diene cyclooctadiene gave no observable chemistry in appreciable amounts.
High Pressure Experiments, XI. Reaction of Phosgene with 1,3-Cyclohexadiene at High Pressure
Kurz, Karlheinz,Plieninger, Hans
, p. 3666 - 3668 (2007/10/02)
Phosgene in toluene reacts at 80 deg C/5000 at with 1,3-cyclohexadiene to yield acyl chlorides.Without pressure no reaction is observed.After esterification the compounds 1-5 could be identified.The Diels-Alder adduct 6 was not observed.
