99864-95-6Relevant academic research and scientific papers
Selective C-H Allylic Oxygenation of Cycloalkenes and Terpenoids Photosensitized by [Cu(Xantphos)(neoc)]BF4
Kallitsakis, Michael G.,Gioftsidou, Dimitra K.,Tzani, Marina A.,Angaridis, Panagiotis A.,Terzidis, Michael A.,Lykakis, Ioannis N.
, p. 13503 - 13513 (2021/09/13)
We present herein for the first time the use of the [Cu(Xantphos)(neoc)]BF4 as a photocatalyst for the selective C-H allylic oxygenation of cycloalkenes into the corresponding allylic hydroperoxides or alcohols in the presence of molecular oxygen. The proposed methodology affords the products at good yields and has also been applied successfully to several bioactive terpenoids, such as geraniol, linalool, β-citronellol, and phytol. A mechanistic study involving also kinetic isotope effects (KIEs) supports the proposed singlet oxygen-mediated reaction. On the basis of the high chemoselectivity and yields and the fast and clean reaction processes observed, the present catalytic system, [Cu(Xantphos)(neoc)]BF4, has also been applied to the synthesis, at a laboratory scale, of the cis-Rose oxide, a well-known perfumery ingredient used in rose and geranium perfumes.
The palladium-catalyzed aerobic kinetic resolution of secondary alcohols: Reaction development, scope, and applications
Ebner, David C.,Bagdanoff, Jeffrey T.,Ferreira, Eric M.,McFadden, Ryan M.,Caspi, Daniel D.,Trend, Raissa M.,Stoltz, Brian M.
supporting information; experimental part, p. 12978 - 12992 (2010/06/19)
The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23°C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-toexcellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.
1,3-BIS(1'-CYCLOALKENYL)BENZENES VIA A TANDEM ARYNE SEQUENCE
Hart, Harold,Ghosh, Tirthankar
, p. 881 - 884 (2007/10/02)
1-Cycloalkenyl Grignard reagents react with 2,6-dibromoiodobenzene to give the title compounds.A route to 1,3-bis(cyclopentadienyl)benzene or its synthetic equivalent is also described.
Solvomercuration-Demercuration. 10. Oxymercuration-Demercuration of Olefins with the Mercuric Salts Acetate, Trifluoroacetate, Nitrate, and Methanesulfonate
Brown, Herbert C.,Geoghegan, Philip J.,Kurek, Joseph T.
, p. 3810 - 3812 (2007/10/02)
The oxymercuration-demercuration of a series of representative olefins has been examined with four mercuric salts: acetate, trifluoroacetate, nitrate, and methanesulfonate.Mono- and 1,2-disubstituted olefins undergo hydration with all four mercuric salts in 90-100percent yields with a regioselectivity for the Markovnikov alcohol (from monoolefins) of >99.5percent.Only styrene was found to be an exception.In marked contrast, only mercuric acetate is effective for the Markovnikov hydration of 1,1-di-, tri- ,and tetrasubstituted olefins.The other three mercuric salts provide loweryields of the tertiary alcohols, yields which decrease rapidly with time. 1-Phenylcyclopentene undergoes only allylic oxidation with the mercuric salts trifluoroacetate, nitrate, and methanesulfonate.Mercuric acetate does give the normal hydration product but only in trace amounts.In this case, allylic oxidation is the major reaction pathway with this salt as well.
