Ligand differentiated complementary Rh-catalyst systems for the enantioselective desymmetrization of meso-cyclic anhydrides
摘要:
Two distinct systems for the rhodium-catalyzed enantioselective desymmetrization of meso-cyclic anhydrides have been developed. Each system has been optimized and are compatible with the use of in situ prepared organozinc reagents. Rhodium/PHOX species efficiently catalyze the addition of alkyi nucleophiles to glutaric anhydrides, while system is effective in the enantioselective arylation of succinic and glutaric anhydrides. (C) 2008 Elsevier Ltd. All rights reserved.
Diaminoalkanes of Formula I have now been found which are orally active and bind to aspartic proteases to inhibit their activity. They are useful in the treatment or amelioration of diseases associated with elevated levels of aspartic protease activity. The invention also relates to a method for the use of the compounds of Formula I in ameliorating or treating aspartic protease related disorders in a subject in need thereof comprising administering to said subject an effective amount of a compound of Formula I.
Diaminoalkanes of Formula I have now been found which are orally active and bind to aspartic proteases to inhibit their activity. They are useful in the treatment or amelioration of diseases associated with elevated levels of aspartic protease activity. The invention also relates to a method for the use of the compounds of Formula I in ameliorating or treating aspartic protease related disorders in a subject in need thereof comprising administering to said subject an effective amount of a compound of Formula I.
Evaluation of (+)-Sparteine-like Diamines for Asymmetric Synthesis
作者:Michael J. Dearden、Matthew J. McGrath、Peter O'Brien
DOI:10.1021/jo049182w
日期:2004.8.1
Three new (+)-sparteine-like diamines were prepared from (-)-cytisine and evaluated as sparteine surrogates in the alpha-lithiation rearrangement of cyclooctene oxide and the palladium(II)/diamine catalyzed oxidative kinetic resolution of I-indanol. The new diamines exhibited opposite enantioselectivity to that observed with (-)-sparteine but increasing the steric hindrance of the N-alkyl group beyond N-Et had a detrimental effect on enantioselectivity. The optimal N-Me diamine was evaluated with much success in five other (-)-sparteine-mediated processes involving different metals (lithium, magnesium, and copper) and different types of reaction mechanisms.