928292-07-3Relevant academic research and scientific papers
Ligand-guided pathway selection in nickel-catalyzed couplings of enals and alkynes
Li, Wei,Montgomery, John
supporting information; experimental part, p. 1114 - 1116 (2012/03/10)
Nickel-catalyzed couplings of enals and alkynes utilizing triethylborane as the reducing agent illustrate a significant dependence on ligand structure. Simple variation of monodentate phosphines allows selective access to alkylative couplings or reductive
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.
Study of the Lewis acid-promoted rearrangement of 2-aryl-2,3-epoxy acylates
Kita, Yasuyuki,Furukawa, Akihiro,Futamura, Junko,Higuchi, Kazuhiro,Ueda, Koichiro,Fujioka, Hiromichi
, p. 815 - 825 (2007/10/03)
The reaction of 2-aryl-2,3-epoxy acylates with Lewis acids was examined in detail. Cyclic 2-aryl-2,3-epoxy acylates afforded the rearranged products via C2-carbocation intermediates. On the other hand, acyclic ones gave the rearranged products via phenonium ion intermediates obtained by C3-cleavage of oxirane rings. The method was also applied to the synthesis of the optically active benzylic quaternary carbon center.
