138624-03-0Relevant articles and documents
Regioselective Diboron-Mediated Semireduction of Terminal Allenes
Gates, Ashley M.,Santos, Webster L.
, p. 4619 - 4624 (2019/12/11)
A method for the regioselective reduction of the terminal double bond of 1,1-disubstituted allenes has been developed. In the presence of a palladium catalyst, tetrahydroxydiboron and stoichiometric water, allene semireduction proceeds in high yield to afford Z-alkenes selectively.
Heteroatom-free arene-cobalt and arene-iron catalysts for hydrogenations
Gaertner, Dominik,Welther, Alice,Rad, Babak Rezaei,Wolf, Robert,Von Wangelin, Axel Jacobi
supporting information, p. 3722 - 3726 (2014/04/17)
75 years after the discovery of hydroformylation, cobalt catalysts are now undergoing a renaissance in hydrogenation reactions. We have evaluated arene metalates in which the low-valent metal species is - conceptually different from heteroatom-based ligands - stabilized by π coordination to hydrocarbons. Potassium bis(anthracene)cobaltate 1 and -ferrate 2 can be viewed as synthetic precursors of quasi-"naked" anionic metal species; their aggregation is effectively impeded by (labile) coordination to the various π acceptors present in the hydrogenation reactions of unsaturated molecules (alkenes, arenes, carbonyl compounds). Kinetic studies, NMR spectroscopy, and poisoning studies of alkene hydrogenations support the formation of a homogeneous catalyst derived from 1 which is stabilized by the coordination of alkenes. This catalyst concept complements the use of complexes with heteroatom donor ligands for reductive processes. Especially high selectivities were observed in the hydrogenation of various alkenes, ketones, and imines with bis(anthracene) cobaltate(-I) [K(dme)2{Co(C14H10)2}] under mild conditions (1-5 mol% cat., 1-10 bar H2, 20-60°C). Mechanistic studies indicate the operation in alkene hydrogenations of a homogeneous catalyst formed by initial ligand exchange and stabilized by the coordination of π-acidic alkenes or arenes.
Liquid crystal control of regio- and diastereoselectivity in the acid-catalyzed elimination of alkyl phosphates to alkenes
Fukunaga, Kenji,Kansui, Hisao,Taniguchi, Tomoko,Kunieda, Takehisa
, p. 8731 - 8734 (2007/10/03)
The E1 reactions of sec- and tert-alkyl phosphates to isomeric olefins, as catalyzed by trifluoromethanesulfonic acid proceed smoothly with remarkably high regio- and diastereoselectivity in a smectic liquid crystalline phase medium, in contrast to isotro
