1808-09-9Relevant articles and documents
Selective dimerization of higher cycloolefins in the presence of micro- and micromesoporous zeolite catalysts
Grigor'Eva,Bubennov,Khazipova,Khalilov,Kutepov
, p. 444 - 449 (2013)
Selective synthesis of dimers of cycloolefins C6-C8 was carried out in the presence of highly dispersed zeolite catalysts HY, HBeta, and HZSM-12 and granulated zeolite HY-WB, which differ in acidic properties and pore structure. The high selectivity of microporous zeolite HZSM-12 in cyclohexene dimerization (100%) and micromesoporous zeolite HY-WB in cycloheptene and cyclooctene dimerization (90-95%) was established.
Metal-organic framework composites with luminescent pincer platinum(II) complexes: 3MMLCT emission and photoinduced dehydrogenation catalysis
Sun, Chun-Yi,To, Wai-Pong,Hung, Faan-Fung,Wang, Xin-Long,Su, Zhong-Min,Che, Chi-Ming
, p. 2357 - 2364 (2018/03/05)
Pincer platinum(ii) complexes are well documented to exhibit weak intermolecular interactions in the solid state and 77 K glassy solutions, leading to emissive triplet metal-metal-to-ligand charge transfer (3MMLCT) excited states that often vanish in dilute solutions. In this work, metal-organic framework (MOF) materials are introduced to provide a "solid solution" environment for easy access to 3MMLCT excited states of pincer platinum(ii) complexes. Phosphorescent composites PtII@MOFs (1-4) with matrix-dependent monomers and oligomer emission properties were obtained. These PtII@MOFs are efficient catalysts for photoinduced dehydrogenation reactions.
Deciphering Photoluminescence Dynamics and Reactivity of the Luminescent Metal-Metal-Bonded Excited State of a Binuclear Gold(I) Phosphine Complex Containing Open Coordination Sites
Ma, Chensheng,Chan, Chris Tsz-Leung,To, Wai-Pong,Kwok, Wai-Ming,Che, Chi-Ming
supporting information, p. 13888 - 13893 (2015/09/28)
Luminescent metal complexes having open coordination sites hold promise in the design of sensory materials and photocatalysts. As a prototype example, [Au2(dcpm)2)]2+ (dcpm = bis(dicyclohexylphosphanyl) is known for its intriguing environmental sensitive photoluminescence. By integrating a range of complementary ultrafast time-resolved spectroscopy to interrogate the excited state dynamics, this study uncovers that the events occurring in extremely rapid timescales and which are modulated strongly by environmental conditions play a pivotal role in the luminescence behavior and photochemical outcomes. Formed independent of the phase and solvent property within 0.15 ps, the metal-metal bonded 35dσ6pσ state is highly reactive possessing strong propensity toward increasing coordination number at AuI center, and with 510 ps lifetime in dichloromethane is able to mediate light induced C-X bond cleavage.
Hydroboration. 86. Convenient Conversion of Aldehydes and Ketones into the Corresponding Alkenes via Hydroboration of their Enamines. A Remarkably Simple Synthesis of Either (Z)- or (E)-Alkenes
Singaram, Bakthan,Rangaishenvi, Milind V.,Brown, Herbert C.,Goralski, Christian G.,Hasha, Dennis L.
, p. 1543 - 1549 (2007/10/02)
Aldehydes and ketones are converted into the corresponding alkenes via hydroboration of their enamines.Hydroboration of aldehyde enamines by 9-borabicyclononane (9-BBN), followed by methanolysis, affords the corresponding terminal alkenes in 75-90percent yields.Unsaturated aldehyde enamines produce the corresponding dienes under these conditions.Enamines derived from substituted cyclic ketones and heterocyclic ketones are readily accommodated in this reaction to afford the corresponding alkenes in very good yields.The synthesis of pure (Z)- or (E)-alkenes is readily achieved from the same acyclic ketone enamine by modification of the hydroboration-elimination procedure: (A) hydroboration by 9-BBN followed by methanolysis or (B) hydroboration by borane methyl sulfide (BMS) followed by methanolysis and hydrogen peroxide oxidation.Mechanistic rationale is provided.
Photochemical Hydroxymethylation of Alicyclic and Aliphatic Alkenes Induced by a EuIII/EuII Photoredox System in Methanol
Ishida, Akito,Yamashita, Shinya,Toki, Susumu,Takamuku, Setsuo
, p. 1195 - 1200 (2007/10/02)
The photoirradiation of a methanol solution of EuCl3 and alkenes such as cyclohexene, cyclooctene, cyclododecene, and tetramethylene afforded (hydroxymethyl)alkane.The dihydro dimer of alkene,hydrogen, and ethylene glycol are also formed.Reactions proceed via a radical mechanism induced by hydrogen atoms and hydroxymethyl radicals, which are produced by a photoredoc reaction of EuIII/EuII in methanol.
Alkylation of Allylic Derivatives. 11. Copper(I)-Catalyzed Cross Coupling of Allylic Carboxylates with Grignard Reagents
Tseng, Chung Chyi,Paisley, Steven D.,Goering, Harlan L.
, p. 2884 - 2891 (2007/10/02)
Reactions of allylic carboxylates with Grignard reagents containing catalytic amounts (1-10 mol percent) of cuprous salts give high yields of cross-coupled products.With alkyl Grignard reagents, regiochemistry can be controlled by choice of cuprous salt.With cuprous halides, little regiospecificity is observed.There is a small excess of γ-coupling in unbiased systems such as 5-methyl-2-cyclohexenyl (1), 2-cyclohexenyl (3), and β-phenylallyl (5) carboxylates.With CuCN, complete regiospecificity (exclusive γ-coupling) is observed with all alkyl Grignard reagents in unbiased systems, and with n-butylmagnesium halide >97percent γ-coupling results with α-methyl-γ-phenylallyl pivalate (7-OPiv) which is biased in favour of coupling at the α-position.In sharp contrast to alkyl Grignard reagents, phenyl and vinyl Grignard reagents containing CuCN show no regiospecificity.
FORMATION OF SULPHUR COMPOUNDS DURING THE HYDRODENITROGENATION OF ANILINE, CYCLOHEXYLAMINE, BENZYLAMINE, AND 2-PHENYLETHYLAMINE ON A NICKEL-TUNGSTEN CATALYST IN THE PRESENCE OF HYDROGEN SULPHIDE
Cerny, Mirko,Trka, Antonin
, p. 2387 - 2392 (2007/10/02)
Hydrodenitrogenations of aniline, cyclohexylamine, benzylamine, and 2-phenylethylamine were performed on a sulphided nickel-tungsten catalyst at 300 deg C in an autoclave filled with hydrogen in the absence and in the presence of hydrogen sulphide.Due to the presence of hydrogen sulphide the degree of conversion increased from 0.9 to 3,6percent for aniline and from 72 to 99percent for benzylamine, and the fraction of neutral substances increased from 2.4 to 7percent for cyclohexylamine and from 5.0 to 8.9percent for 2-phenylethylamine.The neutral fractions contained cyclohexanethiol, thiobenzamide, 2-phenylethanethiol, and other sulphur compounds giving evidence that the increased degree of conversion of the amines was due to the hydrogen sulphide taking direct part in the chemical reaction.
Photochemistry of Cycloalkenes. 9. Photodimerization of Cyclohexene
Kropp, Paul J.,Snyder, John J.,Rawlings, Peter C.,Fravel, Harold G.
, p. 4471 - 4474 (2007/10/02)
The photodimerization of cyclohexene has been restudied.Either direct or triplet-sensitized irradiation produced a stereoisomeric mixture of dimers 6-8, respectively, as primary products with the cis,trans isomer 7 predominating.The direct-irradiation process was complicated by the accompanying formation of the radical-derived products 3-5.Dimerization is interpreted in terms of initial light-induced cis-trans isomerization of cyclohexene, followed by a nonstereospecific ground-states + 2a>addition of trans-cyclohexene to the cis isomer.By contrast, cycloheptene showed little tendency to undergo photodimerization; attempted p-xylene-sensitized dimerization afforded instead principally the sensitizer-olefin adducts 10 and 11.Comparison is made with the copper(I) triflate catalyzed photodimerization of cyclohexene and cycloheptene.
