Synthesis and applications of the first polyfluorous proline derivative
摘要:
Starting from trans-4-hydrocy-L-proline, a polyfluorinated proline derivative having a fluorine content of 54% has been prepared. It has been tested as a catalyst in the aldol reaction between p-nitrobenzaldehyde and acetone with 73% ee in BTF and in copper(I)-catalyzed allylic oxidation of cyclohexene with 20% ee in HFIP. (C) 2003 Elsevier Science Ltd. All rights reserved.
N-Protected hydroxyprolines (Hyp) were transformed chemoselectively into alkoxyproline derivatives by direct O-alkylation. The starting Hyp was transformed into the corresponding dianion in a mixture of dimethyl sulfoxide and tetrahydrofuran (1:16 v/v) as solvent. Under these conditions, the carboxy-anion showed reduced nucleophilicity because it was specifically solvated, and the more reactive oxy-anion
5-(Pyrrolidin-2-yl)tetrazole functionalized silica prepared by photoinduced thiol–ene coupling is packed into a short stainless steel column. The resulting packed-bed microreactor is conveniently heated to perform environmentally benign continuous-flow aldol reactions with good stereoselectivities, complete conversion efficiencies, and long term stability of the packing material.
Silica-supported l-proline organocatalysts for asymmetric aldolisation
作者:Alexandra Zamboulis、Nicolas J. Rahier、Matthias Gehringer、Xavier Cattoën、Gilles Niel、Catherine Bied、Joël J.E. Moreau、Michel Wong Chi Man
DOI:10.1016/j.tetasy.2009.11.024
日期:2009.12
New heterogenised silica-based organocatalysts have been prepared via the sol-gel process from two silylated derivatives Of L-proline, featuring either a carbamate or an ether linker. Co-gelification with variable amounts of TEOS was performed with and without porogen to yield high surface area solids. These materials were evaluated as heterogeneous phase organocatalysts for the asymmetric aldol reaction of p-nitrobenzaldehyde with acetone. (C) 2009 Elsevier Ltd. All rights reserved.
[EN] CYCLIC COMPOUND HAVING INHIBITORY EFFECT SELECTIVE FOR KRAS BUT NOT FOR HRAS AND NRAS<br/>[FR] COMPOSÉ CYCLIQUE AYANT UN EFFET INHIBITEUR SÉLECTIF POUR KRAS MAIS PAS POUR HRAS ET NRAS<br/>[JA] HRASおよびNRASに対して選択的なKRAS阻害作用を有する環状化合物