496-11-7Relevant articles and documents
Photochemistry of 1,2-dihydronaphthaiene oxide: Concurrent triplet and singlet processes via singlet excitation
White, Rick C.,Arney Jr., Benny E.,White, Katherine M.
, p. 8173 - 8177 (2006)
The photochemistry of 1,2-dihydronaphthalene oxide (254 nm) was reexamined and indan was found to be a primary photoproduct, as well as the traditionally assumed secondary photoproduct. Quenching studies demonstrated that indan, as a primary photoproduct, is derived from a triplet pathway, competing with a singlet route, back to the ground state surface. CASSCF calculations strongly suggest that the triplet pathway consists of a dissociation of the oxirane moiety to give a triplet carbene and aldehyde, which via hydrogen abstraction-decarbonylation-ISC recloses to give indan. Conical intersections corresponding to the presumed 1,2-hydrogen shift and 1,2-alkyl shift to give 2-tetralone and 1-indancarbaldehyde, respectively, were located computationally.
The Disproportionation of cis-Bicyclonona-3,7-diene Catalyzed by Fe(CO)5 and Cp2Fe2(CO)4
Kagayama, Takashi,Okabayashi, Shinji,Amaike, Yoichi,Matsukawa, Yasuo,Ishii, Yasutaka,Ogawa, Masaya
, p. 2297 - 2298 (1982)
cis-Bicyclonona-3,7-diene (1) was catalytically disproportionated by the use of Fe(CO)5 and Cp2Fe2(CO)4 to bicyclonon-1(6)-ene (3) and indan (4).However, the same reaction catalyzed by the use of other metal carbonyls gave merely small amount of 3 and 4, while those using Pd- and Rh-carbons yielded only 4 and the starting material, 1, respectively.
Synthesis and Properties of 1,2-Dimethylene-3,5-cycloheptadiene
Oda, Mitsunori,Kuroda, Shigeyasu,Shimao, Ichiro,Morita, Noboru,Asao, Toyonobu
, p. 377 - 378 (1994)
The regioselective synthesis of dimethyl 1,3,5-cycloheptariene-1,2-dicarboxylate (4) was achieved by a ring expansion method, starting from dimethyl 1,3-cyclohexadiene-2,3-dicarboxylate (5).The title compound 3 was obtained as an air-sensitive oil by zinc-copper reduction of 1,2-bis(bromomethyl)cyclohepta-1,3,5-triene (10) to which the diester 4 was transformed.
Generation and Transformation of the Propellane Skeleton by Thermal Rearrangements
Kraemer, Guido,Kolshorn, Heinz,Meier, Herbert
, p. 8353 - 8356 (1994)
In a sequence of unexpected thermal rearrangements the strained monocyclic alkyne 4 is transformed into the tricyclic system 5 which yields in a flash vacuum pyrolysis again a monocyclic compound 10.
Reduction method of electronic salt reaction liquid and unsaturated aromatic hydrocarbon compound
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Paragraph 0084-0087, (2021/11/10)
To the reduction method, tetrahydrofuran is used as a solvent and an electron trapping agent, metal lithium is used as a reducing agent, tertiary butanol is used as a reducing agent, and the unsaturated aromatic hydrocarbon compound is reduced under -10 - 0 °C conditions. The raw material tetrahydrofuran is used in the invention. Metal lithium and tert-butyl alcohol are all conventional chemical products, and are simple and easy to obtain. After the reaction is finished, excess lithium and solvent are recovered, and directly used to realize low cost, low pollution and high yield.
Remarkable catalytic activity of polymeric membranes containing gel-trapped palladium nanoparticles for hydrogenation reactions
López-Viveros, Melissa,Favier, Isabelle,Gómez, Montserrat,Lahitte, Jean-Fran?ois,Remigy, Jean-Christophe
, p. 263 - 269 (2020/05/13)
Polymeric flat-sheet membranes and hollow fibers were prepared via UV photo-initiated polymerization of acrylic acid at the surface of commercial polyether sulfones (PES) membranes. These polymeric materials permitted to immobilize efficiently palladium nanoparticles (PdNP), which exhibited a mean diameter in the range of 4?6 nm. These materials were synthesized by chemical reduction of Pd(II) precursors in the presence of the corresponding support. We successfully applied the as-prepared catalytic materials in hydrogenation reactions under continuous flow conditions. Flat sheet membranes were more active than hollow fibers due to the flow configuration and defavorable operating conditions. Actually, various functional groups (i.e. C[dbnd]C, C[tbnd]C and NO2) were reduced in flow-through configuration, under mild conditions (between 1.4 and 2.2 bar H2 at 60 °C, using 3.2 mol% of Pd loading), archiving high conversions in short reaction times (12?24 s).
Boosting homogeneous chemoselective hydrogenation of olefins mediated by a bis(silylenyl)terphenyl-nickel(0) pre-catalyst
Lücke, Marcel-Philip,Yao, Shenglai,Driess, Matthias
, p. 2909 - 2915 (2021/03/14)
The isolable chelating bis(N-heterocyclic silylenyl)-substituted terphenyl ligand [SiII(Terp)SiII] as well as its bis(phosphine) analogue [PIII(Terp)PIII] have been synthesised and fully characterised. Their reaction with Ni(cod)2(cod = cycloocta-1,5-diene) affords the corresponding 16 VE nickel(0) complexes with an intramolecularη2-arene coordination of Ni, [E(Terp)E]Ni(η2-arene) (E = PIII, SiII; arene = phenylene spacer). Due to a strong cooperativity of the Si and Ni sites in H2activation and H atom transfer, [SiII(Terp)SiII]Ni(η2-arene) mediates very effectively and chemoselectively the homogeneously catalysed hydrogenation of olefins bearing functional groups at 1 bar H2pressure and room temperature; in contrast, the bis(phosphine) analogous complex shows only poor activity. Catalytic and stoichiometric experiments revealed the important role of the η2-coordination of the Ni(0) site by the intramolecular phenylene with respect to the hydrogenation activity of [SiII(Terp)SiII]Ni(η2-arene). The mechanism has been established by kinetic measurements, including kinetic isotope effect (KIE) and Hammet-plot correlation. With this system, the currently highest performance of a homogeneous nickel-based hydrogenation catalyst of olefins (TON = 9800, TOF = 6800 h?1) could be realised.
Synthesis of renewable alkylated naphthalenes with benzaldehyde and angelica lactone
Cong, Yu,Li, Guangyi,Li, Ning,Wang, Aiqin,Wang, Ran,Wang, Xiaodong,Xu, Jilei,Zhang, Tao
supporting information, p. 5474 - 5480 (2021/08/16)
Herein, we report a new route for the synthesis of renewable alkylated naphthalenes (ANs) with benzaldehyde and angelica lactone, two platform compounds that can be derived from lignocellulose.
N-Atom Deletion in Nitrogen Heterocycles
Cai, Wangshui,Guo, Ting,Li, Guigen,Lu, Hongjian,Qin, Haitao,Wang, Shuang
, p. 20678 - 20683 (2021/08/25)
Excising the nitrogen in secondary amines, and coupling the two residual fragments is a skeletal editing strategy that can be used to construct molecules with new skeletons, but which has been largely unexplored. Here we report a versatile method of N-atom excision from N-heterocycles. The process uses readily available N-heterocycles as substrates, and proceeds by N-sulfonylazidonation followed by the rearrangement of sulfamoyl azide intermediates, providing various cyclic products. Examples are provided of deletion of nitrogen from natural products, synthesis of chiral O-heterocycles from commercially available chiral β-amino alcohols, formal inert C?H functionalization through a sequence of N-directed C?H functionalization and N-atom deletion reactions in which the N-atom can serve as a traceless directing group.
Metal-Free Heterogeneous Semiconductor for Visible-Light Photocatalytic Decarboxylation of Carboxylic Acids
Shi, Jiale,Yuan, Tao,Zheng, Meifang,Wang, Xinchen
, p. 3040 - 3047 (2021/03/09)
A suitable protocol for the photocatalytic decarboxylation of carboxylic acids was developed with metal-free ceramic boron carbon nitrides (BCN). With visible light irradiation, BCN oxidize carboxylic acids to give carbon-centered radicals, which were trapped by hydrogen atom donors or employed in the construction of the carbon-carbon bond. In this system, both (hetero)aromatic and aliphatic acids proceed the decarboxylation smoothly, and C-H, C-D, and C-C bonds are formed in moderate to high yields (35 examples, yield up to 93%). Control experiments support a radical process, and isotopic experiments show that methanol is employed as the hydrogen atom donor. Recycle tests and gram-scale reaction elucidate the practicability of the heterogeneous ceramic BCN photoredox system. It provides an alternative to homogeneous catalysts in the valuable carbon radical intermediates formation. Moreover, the metal-free system is also applicable to late-stage functionalization of anti-inflammatory drugs, such as naproxen and ibuprofen, which enrich the chemical toolbox.
