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The publisher regrets that the below dedication to Prof. Richard. Taylor was not included in the above article. “Dedicated to Prof. Richard. Taylor for his superb contribution to organic chemistry as researcher and editor.” The publisher would like to apologise for any inconvenience caused.

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.

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.

Synthetic paths towards highly functionalized alpha-chlorocyclobutanone scaffolds susceptible to lead to serine proteases inhibitors were explored. The syntheses started from bicyclic alpha-chlorocyclobutanones 3, which are readily available from Seebach's oxazolines. It was found that the carbonyl group of the bicyclic alpha-chlorocyclobutanones was highly electrophilic and readily reacted with a hydroxy group to give, for example, cyclized compound 4. Also, the presence of this reactive carbonyl group did not allow the regeneration of the protected amine and hydroxy groups. Thus, the functional manipulation of these bicyclic alpha-chlorocyclobutanones required prior reduction of the carbonyl group to the corresponding cyclobutanol. Accordingly, enantiopure cyclobutanone 3d was stereoselectively reduced to exo-cyclobutanol 15. Allylation of the alcohol followed by TEMPO-catalyzed oxidation of the primary alcohol of the side chain and benzylation of the resulting carboxylic acid yielded compound 19. Cleavage of the oxazolidine ring occurred smoothly to yield densely functionalized cyclobutanol scaffold 20. A similar route allowed the efficient preparation of cyclobutanol scaffolds 14 and 25a-d in 25-27% yields. TEMPO-catalyzed oxidation of the cyclobutanol gave an excellent yield of corresponding cyclobutanones 26a,b ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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.

Acid-promoted asymmetric sulfoxidations of prochiral sulfides using binaphthyl-derived oxaziridines have been studied. The reactions of dialkyl or aryl-alkyl sulfides gave good yields of the corresponding sulfoxides with enantiopurities ranging from 20% to 80%. The influence of temperature and strength of the acid catalyst on enantioselectivity was studied. The absolute configuration of the resulting major enantiomer varied with the structure of the sulfide. (c) 2007 Elsevier Ltd. All rights reserved.

This PhD thesis deals with the activation of diorganozinc compounds by asymmetric catalysts in the framework of their enantioselective addition on carbon oxygen and carbon nitrogen double bonds. The properties of several new catalysts systems were investigated. Several chiral sulfonamido alcohols derived from (S)-leucinol and (1S) 3 aminoisoborneol were synthesized to cover a range of electronic and steric properties. These were evaluated in the addition of Et2Zn to N phosphinoyl and N sulfonyl-imines, but they did not provide any acceptable yields or enantioselectivities while used in stoichiometric quantities. Their catalytic properties were also investigated for the addition of Et2Zn to benzaldehyde. Unfortunately, only modest enantiocontrol (max. 47% ee) could be obtained with 10mol% of chiral ligand. We investigated another approach based on the possible activation of the nucleophilicity of dialkylzinc compounds towards benzaldehyde by fluoride anion. The combination of stoichiometric amount of an inorganic fluoride salt and a substoichiometric amount of a phase transfer catalyst (10mol% of crown ether 18 C 6) provided non-negligible rate acceleration. However, an asymmetric version of this catalytic system was not considered. Following our discovery of the activation provided by the fluoride anion, metal fluoride complexes were tapped as potential catalysts. In particular, copper(I) fluoride complex, (Ph3P)3CuF, was shown to accelerate the reaction on benzaldehyde. After screening a range of ligands, the combination of (Ph3P)3CuF and chiral BINAP in catalytic amounts (1mol%) was found to catalyze efficiently the Et2Zn addition on aromatic aldehydes. Yields were good but enantiocontrol was modest (49-63% ee). An improved copper fluoride-based catalyst was developed by combining a copper salt, a fluoride source and a chiral diphosphine ligand. Optimization of this second generation catalyst was carried out (copper source, fluoride source, chiral ligand, relative, Cette dissertation traite de l'activation de composés diorganozinciques par des catalyseurs asymétriques dans le cadre de leur addition énantiosélective sur des doubles liaisons carbone-oxygène et carbone-azote. Les propriétes de divers catalyseurs originaux ont été investiguées. Plusieurs sulfonamidoalcools chiraux dérivés du (S)-leucinol et du (1S) 3 aminoisoborneol ont été synthétisés pour couvrir un domaine de propriétés électroniques et stériques. Ceux-ci ont été testés lors l'addition du Et2Zn sur les N phosphinoyl et N-sulfonyl-imines, mais ils n'ont pas fourni de rendements et excès énantiomériques intéressants malgré leur utilisation en quantité stoechiométrique. Leurs propriétés catalytiques ont également été examinées dans le cadre de l'addition de Et2Zn au benzaldéhyde. Malheureusement, un faible contrôle de l'énantiosélectivité (max. 47% ee) est obtenu en présence de 10mol% de ligand chiral. Une autre approche abordée concerne l'influence de l'anion fluorure sur la nucléophilie des composés dialkylzincs envers le benzaldehyde. La combinaison de quantités stoechiométriques d'un sel fluoré inorganique et d'une quantités sub stoechiométrique d'un agent de transfert de phase (10mol% éther couronne 18 C 6) conduit à un accroissement non négligeable de la vitesse de réaction. Toutefois, le développement d'une version asymétrique de ce système n'a pas été considéré. A la suite de notre découverte de l'activation due à l'anion fluorure, les complexes métalliques fluorés ont été examinés en tant que catalyseurs potentiels. En particulier, le complexe du cuivre, (Ph3P)3CuF, accélère la réaction d'addition du Et2Zn sur le benzaldéhyde. Après un criblage de divers ligands, la combinaison de (Ph3P)3CuF et de la diphosphine chirale BINAP en quantité catalytique (1mol%) conduit à une catalyse efficace de l'addition du Et2Zn sur des aldéhydes aromatiques. Les rendements obtenus sont bons, par contre l'énantiosélectivité est modeste (49-63% ee). Une version améliorée de, (CHIM 3)--UCL, 2005