ESCH, PETER M.;HIEMSTRA, HENK;SPECKAMP, W. NICO, TETRAHEDRON LETT., 31,(1990) N, C. 759-762
作者:ESCH, PETER M.、HIEMSTRA, HENK、SPECKAMP, W. NICO
DOI:——
日期:——
Reductive cyclization of carbon-centered glycine radicals; a novel synthetic route to cyclic α-amino acids
作者:Peter M. Esch、Henk Hiemstra、Richard F. de Boer、W.Nico Speckamp
DOI:10.1016/s0040-4020(01)81240-0
日期:1992.1
Reductive cyclizations (tributylin hydride, AIBN) of several α-(penthylthio)glycine derivatives with a 30alkenyl substituent at nitrogen are reported. These reactions proceed via 2-aza-5-alken-1-yl radicals as intermediates which bear electron-withdrawing carbonyl substituents at the radical center and at nitrogen. Such radicals can be considered as relatively stable captodative radicals, but are reactive
N-Boc or N-Cbz homoallylic amines are converted in four steps into pyrrolidines through a sequence involving as a key-step a tandem zinc mediated reductive cleavage-reductive amination from an intermediate 1,3-oxazin-2-one