Highly enantioselective monoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditions
摘要:
The selective monoalkylation of glycine tert-butyl ester aldimine Schiff base 3 has been realized in high chemical yield with excellent enantioselectivity under mild liquid-liquid phase-transfer conditions by the use of binaphthyl-derived chiral quaternary ammonium bromides 7 and 8 as catalysts. This achievement demonstrates that 3 can be used as a cost-effective substrate for the preparation of optically active alpha-alkyl-alpha-amino, acid derivatives by chiral phase-transfer catalysis. (c) 2006 Elsevier Ltd. All rights reserved.
In this paper, we describe investigations into the use of cinchona alkaloid-derived quaternary ammonium phase-transfercatalysts for the asymmetric alkylation of a benzophenone-derived glycine-imine. Utility of this process is demonstrated by the enantioselectivesynthesis of a range of α-aminoacid esters.
A new class of asymmetric phase-transfer catalysts derived from Cinchona alkaloids — Application in the enantioselective synthesis of α-amino acids
作者:Barry Lygo、Philip G. Wainwright
DOI:10.1016/s0040-4039(97)10293-3
日期:1997.12
new class of Cinchona alkaloid-derived quaternary ammonium phase-transfercatalysts bearing a N-anthracenylmethyl function are presented. These catalysts show high stereocontrol in the asymmetric alkylation of a benzophenone-derived glycine-imine, and application of this process to the enantioselectivesynthesis of a range of α-aminoacid esters (e.e. 67–94%) is investigated.
Recoverable Dendritic Phase-Transfer Catalysts that Contain (+)-Cinchonine-Derived Ammonium Salts
作者:Jordi Rull、José Juan Jara、Rosa M. Sebastián、Adelina Vallribera、Carmen Nájera、Jean-Pierre Majoral、Anne-Marie Caminade
DOI:10.1002/cctc.201600283
日期:2016.6.21
The asymmetric alkylation of a glycinate Schiff base with benzyl bromide is used as a benchmark reaction, and the dendrimeric catalyst that contains an allyl group on the O‐9 hydroxy group of the cinchonine units is the most active. The recovery and reuse of the catalyst are possible for five consecutive runs without loss of activity and with only a slight decrease in enantioselectivity. If other electrophiles
Evaluation of the Efficiency of the Chiral Quaternary Ammonium Salt β-Np-NAS-Br in the Organic-Aqueous Phase-Transfer Alkylation of a Protected Glycine Derivative
allylation of glycine tert-butyl ester benzophenone Schiff base (1). This revealed the practical conditions for the asymmetric synthesis of both natural and unnatural α-amino acids, whose usefulness was demonstrated by the formal enantioselective synthesis of antibioticL-azatyrosine.
Compounds with Matrix-Metalloproteinase Inhibitory Activity and Imaging Agents Thereof
申请人:Kolb Hartmuth C.
公开号:US20120282180A1
公开(公告)日:2012-11-08
The present invention relates to the field of therapeutic and diagnostic agents and more specifically to compounds of formula (I) that are inhibitors of matrix-metalloproteinases (MMPs) and are useful in the treatment of diseases related thereto such as cardiovascular diseases, inflammatory diseases and malignant diseases. One embodiment of the invention is a compound of formula (I) labeled with a 18-fluorine atom having matrix metalloproteinase inhibitory activity suitable for diagnostic imaging. Also disclosed in the present invention is a pharmaceutical composition comprising the inhibitors of matrix-metalloproteinases (MMPs) of the invention or the corresponding labeled compounds useful as diagnostic imaging agents of the invention in a form suitable for mammalian administration. The invention furthermore discloses intermediates in the synthesis of the inhibitors of matrix-metalloproteinases (MMPs) of the invention and of the diagnostic imaging agents of the invention and kits for the preparation of the pharmaceutical composition of the invention.