Loos, Walter A. J. de; Kuijk, Anne J. W. van den Berg-van; Iersel, Hans M. van, Recueil des Travaux Chimiques des Pays-Bas, 1980, vol. 99, # 2, p. 53 - 57
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
Transition-metal-centered radicals in organic synthesis. Titanium(III)-induced cyclization of epoxy olefins
作者:William A. Nugent、T. V. RajanBabu
DOI:10.1021/ja00233a051
日期:1988.12
allows the direct synthesis of functionalized cyclopentane derivatives. This new reaction is based on an analogy to the extremely facilerearrangement of cyclopropylmethyl radical to homoallyl radical (eq 2). A a-complex of an epoxide with a paramagnetic transition metal4 having a half-filled (*-symmetry) d orbital represents an electronic analogue of the cyclopropylmethyl moiety. By analogy to eq 2, release