The search for tolerant Lewis acid catalysts. Part2: enantiopure cycloalkyldialkylsilyl triflimide catalysts

A series of 2-aryl-and arylmethyl-3-dialkylphenylsilyl cycloalkanones have been prepared and resolved. The pure enantiomers were reduced to the corresponding cycloalkane derivatives. These were used for the in situ generation of enantiopure cycloalkylsilyl triflimides by protodesilylation with bis( trifluoromethanesulfonyl) imide. The association of a bulky leaving group with a silicon atom carrying large substituents was again shown to favour the complexation of silicon with carbonyl groups: all these trialkylsilyl triflimides showed a high catalytic activity for Diels -Alder reactions. Enantiomeric excesses up to 59% were observed. This is the highest enantioselectivity ever observed for a Diels-Alder reaction catalysed by a silicon Lewis acid. (c) 2007 Elsevier Ltd. All rights reserved

A lifetime journey into the world of chemistry

The professional life of the author has been a fascinating journey through the magnificent landscapes of synthetic organic chemistry. A friendly editor invited him to share a few of these travel memories. This review is thus a (very) personal and (totally) prejudiced account of the author's research in organic chemistry. It describes the work of his associates and coworkers at UCLouvain in Belgium or at IECB in France. All schemes only deal with work which was done in both research groups. The names of the coworkers will appear in the references. The author apologizes to those coworkers whose work has not been cited but he had to sail within his pages' allocation. As will be seen, many areas of organic synthesis have been visited. The results of the research were put into perspective with the status of the field when the research was undertaken. Obviously several of these fields of research have dramatically expanded later on; credit could not be given here to these important developments. However, when available, some recent reviews will be cited to give a flavour of the most recent work. Thus, the reader should not expect to read a “classical” review of a topical subject. The purpose of this paper is merely the sharing of professional experiences of a modest but enthusiastic teacher and researcher

Polymérisation et copolymérisation de la N-Vinylurethane.

Docteur en Sciences -- Université catholique de Louvain, 195

«Synthesis: science or technology?» : a few comments from an old-timer

This short commentary adresses some problems associated with the present status and the future of research in organic synthesis. It simply reflects the personal opinion of an author who has been involved with organic synthesis for more than 50 years

Catalytic reaction pathways approached by quantum chemistry: a challenge

This review explores the potential of quantum chemistry to help understand complex biochemical reactions such as enzyme catalysis. Starting from a historical background, the article introduces the reader to the great diversity of problems than can be dealt with in the framework of quantum chemistry

N-trimethylsilyl-bis(trifluoromethanesulfonyl)imide: a better carbonyl activator than trimethylsilyl triflate.

N-trimethylsilyl-bis(trifluoromethanesulfonyl)imide (TMSNTf2) was readily prepared from allyltrimethylsilane and bis(trifluoromethanesulfonyl)imide. It was shown to complex carbonyl groups much more effectively than trimethylsilyl triflate. As a result, TMSNTF2 was found to be superior to TMSOTf as a catalyst for the Diels-Alder reaction of methyl acrylate with various dienes. (C) 1997 Elsevier Science Ltd

Conception & synthèse d'activateurs de la protéine proapoptotique Bax

L'apoptose ou mort cellulaire programmée est indispensable au maintien de l'homéostasie tissulaire. Ses dysfonctionements, par excés ou par défaut, sont à l'origine de nombreuses pathologies (cancer, maladies neurodégénératives...). Les protéines de la famille Bcl-2 sont des régulateurs importants du processus apoptotique. Bax est un membre proapoptotique de cette famille : suite à un stimulus, elle subit un changement conformationnel qui opermet son insertion dans la membrane mitochondriale puis le déclenchement de l'apoptose. Au cours de cette thèse, nous avons cherché à développer des composés pouvant agir sur le site actif de cette protéine. Ceci est en effet une stratégie de choix pour le développement de nouvelles drogues proapoptotiques. Des études de modélisation moléculaire, basées sur la structure RMN de Bax, ont permis la conception de composés potentiellement inducteurs de l'apoptose de structure tricyclique. Ces nouveaux composés possèdent une structure pyridoquinoléine fonctionnalisée en alpha de la fonction amide par un groupement aromatique et par une bras de type oxypropionique en position 8. Nous avons ensuite développé une voie de synthèse rapide et concergente, nous permettant d'introduire facilement de la diversité structurale lors des dernières étapes de la synthèse dans le but d'établir une étude SAR. Les tests biologiques des premiers composés synthétisés sont acutellement en cours.BORDEAUX1-BU Sciences-Talence (335222101) / SudocSudocFranceF