Sustainable radical reduction through catalyzed hydrogen atom transfer reactions (CHAT-reactions)
作者:Andreas Gansäuer、Matthias Otte、Frederik Piestert、Chun-An Fan
DOI:10.1016/j.tet.2009.03.088
日期:2009.6
system with coupled catalytic cycles is described that allows radicalreduction by catalyzed hydrogenatomtransfer (CHAT) from transition metal hydrides. These intermediates are generated through H2 activation. Radical generation is carried out by titanocene catalyzed electron transfer to epoxides. The reaction provides a novel entry into the atom-economical reduction of radicals that has long been
Dramatic rate acceleration in titanocene catalyzed epoxide openings: cofactors and Lewis acid cocatalysis
作者:Andreas Gansäuer、Harald Bluhm
DOI:10.1039/a805246h
日期:——
High synthetic efficiency concerning yield and catalytic turn-over in intermolecular C–C bond forming reactions of radicals derived from epoxides can be achieved by means of hydrogen bonding with cofactors or by Lewis acid cocatalysis.
Sustainable Radical Reduction through Catalytic Hydrogen Atom Transfer
作者:Andreas Gansäuer、Chun-An Fan、Frederik Piestert
DOI:10.1021/ja801232t
日期:2008.6.1
A system with coupled catalytic cycles is described that allows radicalreduction by hydrogenatom abstraction from rhodium hydrides. These intermediates are generated from H2 activation by Wilkinson's catalyst. Radical generation is carried out by titanocene-catalyzed electron transfer to epoxides.
Catalytic, Highly Regio- and Chemoselective Generation of Radicals from Epoxides: Titanocene Dichloride as an Electron Transfer Catalyst in Transition Metal Catalyzed Radical Reactions
The preparatively important catalytic opening of epoxides to β-titanoxy radicals via single-electron transfer (SET) is described. These radicals can be reduced to alcohols or participate in C−C bond-forming reactions. A key step in the catalytic cycle is the conceptually novel protonation of titanium−oxygen and −carbon bonds. Our method combines the advantages of radical reactions, e.g., high functional