Objectif The project was targeted at the rational design and synthesis of novel and effective chiral reagents for asymmetric synthesis. Emphasis was placed on developing new asymmetric aldol methodology based on chiral boron enolates by transition state modelling using ab initio MO and MM2 calculations. Conformational analysis of the possible diastereomeric transition states was used to assess the sense and degree of stereoselectivity for a wide range of aldol reaction types. The most promising chiral reagents to come from the modelling work were then prepared and their general effectiveness tested experimentally. Several new reagents have been developed using the 'rational design/molecular modelling' approach. These new reagents allow the synthesis of complex molecules containing multiple stereocentres and are, in principle, exploitable by pharmaceutical companies and/or by the fine chemical industry. The synthesis and application of these reagents have been published in the scientific literature. A force field was developed to model the transition structures of the boron mediated aldol reaction. The force field has been published in scientific journals. The parameters were included in the distributed version of the commercial package MacroModel (W C Still, Columbia University, New York) in order to make it available to the scientific community.The proposed project is for the rational design and synthesis of novel and effective chiral reagents for asymmetric synthesis. This work will be based on using ab initio MO and MM2 calculations for modelling the transition states for various addition reactions at sp2 carbon atoms. Emphasis will initially be placed on developing new and general asymmetric aldol methodology based on boron and titanium enolates. Conformational analysis of the possible diastereomeric transition states, when chiral substituents are involved, will be used to assess the sense and degree of reaction stereoslectivity. The most promising chiral reagents to come from the modelling work would be prepared and their general effectiveness tested. Champ scientifique natural scienceschemical sciencesorganic chemistryorganic reactionsnatural scienceschemical sciencesinorganic chemistrytransition metalsnatural scienceschemical sciencesinorganic chemistrymetalloids Programme(s) FP2-SCIENCE - Programme plan (EEC) to stimulate the international cooperation and interchange needed by European research scientists (SCIENCE), 1988-1992 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE Contribution de l’UE Aucune donnée Adresse Trinity Lane, The Old Schools, CB2 1TN CAMBRIDGE Royaume-Uni Voir sur la carte Coût total Aucune donnée Participants (1) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire THE UNIVERSITY OF MILANO Italie Contribution de l’UE Aucune donnée Adresse Via Venezian 21 20133 MILANO Voir sur la carte Coût total Aucune donnée