3391-07-9Relevant academic research and scientific papers
A useful, reliable and safer protocol for hydrogenation and the hydrogenolysis of o-benzyl groups: The in situ preparation of an active Pd 0/C catalyst with well-defined properties
Felpin, Francois-Xavier,Fouquet, Eric
supporting information; experimental part, p. 12440 - 12445 (2011/01/05)
A simple, highly reproducible protocol for the hydrogenation of alkenes and alkynes and for the hydrogenolysis of O-benzyl ethers has been developed. The method features the in situ preparation of an active Pd0/C catalyst from Pd(OAc)2 and charcoal, in methanol. The mild reaction conditions (25°C) and low catalyst loading required (0.025 mol%), as well as the absence of contamination of the product by palladium residues (0/C: It's a kind of magic! A sustainable, simple and highly reproducible protocol for the hydrogenation of alkenes and alkynes (see scheme) and for the hydrogenolysis of O-benzyl ethers has been developed with an in situ generated Pd0/C catalyst. The homemade Pd0/C catalyst allows mild reaction conditions (25°C, 1 atm H2) and low catalyst loading (as low as 0.025 mol%), without any contamination of the product by palladium residues (4 ppb).
Stereoselectivity in the rhodium-catalysed reductions of nonconjugated dienes
Nguyen, Bao,Brown, John M.
scheme or table, p. 1333 - 1343 (2009/12/27)
The stereochemical course of rhodium-catalysed addition of hydrogen and catecholborane to bicyclo[2.2.1]heptadiene, and of hydrogen to a range of cyclic dienes has been analysed. For hydroboration, the overall catalytic reaction possesses exo-selectivity, but the initial step is endo-selective. For hydrogenation (deuteration), the first step may occur with either exo- or endo- selectivity, depending on the structure of the diene. This enables a distinction to be made between pathways involving prior dissociation of the diene, and direct addition to the complexed diene without full dissociation. The relative ease of hydrogenation of the first and second doublebonds varies markedly with reactant structure, and also depends on the choice of catalyst ligands. For dicyclopentadiene, hydrogenation of the cyclopentene double bond is accompanied by rapid alkene isomerisation, as revealed by deuterium addition. The asymmetric hydrogenation of acyclic skipped mesodienes is reported, demonstrating control of relative rates of the two sequential steps, with ees of up to 53% after the first reduction.
Effect of Remote Substituents upon the Long-Range Aryl Migration and Electrocyclic Ring Opening of exo-3,3-Diaryltricyclo2,4>octan-anti-8-yl Tosylates in Solvolysis
Wilt, James W.,Curtis, Veronica A.,O-Yang, Counde
, p. 3721 - 3730 (2007/10/02)
The processes of long-range aryl migration (LRAM) and electrocyclic ring opening (ERO) that occur in the solvolysis of the title substrates have been investigated with respect to their relative timing.By substituting an electron-withdrawing group (CN) or
