A practical enantioselective synthesis of .alpha.,.alpha.-diaryl-2-pyrrolidinemethanol. Preparation and chemistry of the corresponding oxazaborolidines
摘要:
A practical two-step enantioselective synthesis of alpha,alpha-diaryl-2-pyrrolidinemethanols (1) from proline, based on the addition of aryl Grignard reagents to proline-N-carboxanhydride (3), is reported. An investigation into the chemistry of the corresponding B-alkyl- and B-aryloxazaborolidines (2) led to the development of a reliable procedure for their preparation.
Synthesis and Discovery of <i>N</i>-Carbonylpyrrolidine- or <i>N</i>-Sulfonylpyrrolidine-Containing Uracil Derivatives as Potent Human Deoxyuridine Triphosphatase Inhibitors
development as part of a new strategy of 5-fluorouracil-based combination chemotherapy. We have initiated a program to develop potent drug-like dUTPase inhibitors based on structure–activity relationship (SAR) studies of uracil derivatives. N-Carbonylpyrrolidine- and N-sulfonylpyrrolidine-containing uracils were found to be promising scaffolds that led us to human dUTPase inhibitors (12k) having excellent
Copolymerization of Cyclohexene Oxide with CO2 by Using Intramolecular Dinuclear Zinc Catalysts
作者:Youli Xiao、Zheng Wang、Kuiling Ding
DOI:10.1002/chem.200401159
日期:2005.6.6
into the Zn--OEt bond to afford a carbonate-ester-bridged complex. The dinuclearzinc structure of the catalyst remains intact throughout the copolymerization. The bridged zinc centers may have a synergistic effect on the copolymerization reaction; one zinc center could activate the epoxide through its coordination and the second zinc atom may be responsible for carbonate propagation by nucleophilic attack
2.1 Die bekannten Verfahren zur Herstellung homochiraler Aminoalkohole der Formel I
worin R¹, R², R³ und * die in der Beschreibung angegebene Bedeutung aufweisen, durch Umsetzung der entsprechenden Säure mit metallorganischen Verbindungen sind entweder aufwendig, ergeben eine geringe Ausbeute oder auch nur geringe Enantiomerenreinheit. Das neue Verfahren soll diese Nachteile vermeiden.
2.2 Erfindungsgemäß werden N-silylierte Aminosäuresilylester der Formel II
worin R¹, R², R⁴ und * die in der Beschreibung angegebene Bedeutung haben, mit metallorganischen Verbindungen, insbesondere Grignard-Reagenzien in hoher Ausbeute und Enantiomerenreinheit umgesetzt.
2.3 Chirale Katalysatoren in der enantioselektiven Reduktion unsymmetrischer Ketone.