A "(+)-sparteine-like" chiral diamine, readily synthesized in three steps from (-)-cytisine, has been evaluated in four different asymmetric transformations; in each case, selectivity in an enantiocomplementary fashion to (-)-sparteine was observed.
Synthesis of sparteine-like chiral diamines and evaluation in the enantioselective lithiation–substitution of N-(tert-butoxycarbonyl)pyrrolidine
作者:Jean-Paul R. Hermet、David W. Porter、Michael J. Dearden、Justin R. Harrison、Tobias Koplin、Peter O'Brien、Jérôme Parmene、Vladimir Tyurin、Adrian C. Whitwood、John Gilday、Neil M. Smith
DOI:10.1039/b308410h
日期:——
methods. These diamines lacked the bispidine framework of (-)-sparteine and were found to impart vastly inferior enantioselectivity. It was concluded that, for the asymmetric lithiation substitution of N-Boc pyrrolidine, a rigid bispidine framework and only three of the four rings of (-)-sparteine are needed for high enantioselectivity. Furthermore, it is shown that diamine (1R,2S,9S)-11-methyl-7,11-diazatricyclo[7
作者:Michael J. Dearden、Catherine R. Firkin、Jean-Paul R. Hermet、Peter O'Brien
DOI:10.1021/ja027774v
日期:2002.10.1
A "(+)-sparteine-like" chiral diamine, readily synthesized in three steps from (-)-cytisine, has been evaluated in four different asymmetric transformations; in each case, selectivity in an enantiocomplementary fashion to (-)-sparteine was observed.
Abstract Twenty-five quinolizidinealkaloids, and the dipiperidyl alkaloid, ammodendrine, have been found in Petteriaramentacea. Nineteen alkaloids are described for the first time in this plant. Cytisine-12-carboxy-methylester represented a new quinolizidinealkaloid. The distribution of alkaloids in buds, leaves, flowers, ripe pods, unripe fruits, seeds, stem bark, stem wood and roots was investigated