18952-34-6Relevant articles and documents
SYNTHESIS AND APPLICATION OF CHIRAL SUBSTITUTED POLYVINYLPYRROLIDINONES
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Paragraph 0046; 0047, (2020/11/24)
Chiral polyvinylpyrrolidinone (CSPVP), complexes of CSPVP with a core species, such as a metallic nanocluster catalyst, and enantioselective oxidation reactions utilizing such complexes are disclosed. The CSPVP complexes can be used in asymmetric oxidation of diols, enantioselective oxidation of alkenes, and carbon-carbon bond forming reactions, for example. The CSPVP can also be complexed with biomolecules such as proteins, DNA, and RNA, and used as nanocarriers for siRNA or dsRNA delivery.
Chiral-Substituted Poly-N-vinylpyrrolidinones and Bimetallic Nanoclusters in Catalytic Asymmetric Oxidation Reactions
Hao, Bo,Gunaratna, Medha J.,Zhang, Man,Weerasekara, Sahani,Seiwald, Sarah N.,Nguyen, Vu T.,Meier, Alex,Hua, Duy H.
supporting information, p. 16839 - 16848 (2017/01/10)
A new class of poly-N-vinylpyrrolidinones containing an asymmetric center at C5 of the pyrrolidinone ring were synthesized from l-amino acids. The polymers, particularly 17, were used to stabilize nanoclusters such as Pd/Au for the catalytic asymmetric oxidations of 1,3- and 1,2-cycloalkanediols and alkenes, and Cu/Au was used for C-H oxidation of cycloalkanes. It was found that the bulkier the C5 substituent in the pyrrolidinone ring, the greater the optical yields produced. Both oxidative kinetic resolution of (±)-1,3- and 1,2-trans-cycloalkanediols and desymmetrization of meso cis-diols took place with 0.15 mol % Pd/Au (3:1)-17 under oxygen atmosphere in water to give excellent chemical and optical yields of (S)-hydroxy ketones. Various alkenes were oxidized with 0.5 mol % Pd/Au (3:1)-17 under 30 psi of oxygen in water to give the dihydroxylated products in >93% ee. Oxidation of (R)-limonene at 25 °C occurred at the C-1,2-cyclic alkene function yielding (1S,2R,4R)-dihydroxylimonene 49 in 92% yield. Importantly, cycloalkanes were oxidized with 1 mol % Cu/Au (3:1)-17 and 30% H2O2 in acetonitrile to afford chiral ketones in very good to excellent chemical and optical yields. Alkene function was not oxidized under the reaction conditions. Mechanisms were proposed for the oxidation reactions, and observed stereo- and regio-chemistry were summarized.
Efficient ruthenium-catalyzed transfer hydrogenation/hydrogenation of 1,3-cycloalkanediones to 1,3-cycloalkanediols using microwave heating
Leijondahl, Karin,Fransson, Ann-Britt L.,Baeckvall, Jan-E.
, p. 8622 - 8625 (2007/10/03)
A number of 1,3-cycloalkanediones were efficiently reduced to the corresponding diols in good yield by the use of a ruthenium catalyst, 2-propanol, and hydrogen gas under microwave heating.
Synthesis of cyclohexenols and cycloheptenols via the regioselective reductive ring opening of oxabicyclic compounds
Lautens, Mark,Ma, Shihong,Chiu, Pauline
, p. 6478 - 6487 (2007/10/03)
The reductive ring opening of oxabicyclic compounds has been achieved. While RMgBr/MgBr2 works in a few limited substrates, diisobutylaluminum hydride reacts with oxabicyclic[3.2.1]- and -[2.2.1]alkenes to provide cycloheptenols and cyclohexeno
Stereospecific Synthesis of cis- and trans-2,3-Epoxycycloheptanol
Kim, Sang-Won,Nagao, Keishiro,Yoshimura, Isotaka,Ozaki, Yutaka
, p. 989 - 992 (2007/10/02)
cis- and trans-2,3-Epoxycycloheptanols were prepared stereospecifically from cyclohept-2-en-1-ol (1).Oxidation of 1 with tert-butyl hydroperoxide in the presence of a molybdenum catalyst gave the cis isomer (2) in high yield.The trans isomer (3) was obtained via the bromohydrin (4).The structure of 4 is discussed. Keywords---cis-2,3-epoxycycloheptanol; trans-2,3-epoxycycloheptanol; stereospecific epoxidation; molybdenum hexacarbonyl; regiospecific bromohydrin formation; protection of hydroxyl group
