Copper-Catalyzed Asymmetric Conjugate Addition of Dimethylzinc to Acyl-N-methylimidazole Michael Acceptors: a Powerful Synthetic Platform.
An efficient copper-catalyzed enantioselective conjugate addition of dimethylzinc to α,β- and α,β,γ,δ-unsaturated 2-acyl-N-methylimidazoles has been achieved using a chiral bidentate hydroxyalkyl-NHC ligand. The reactions proceeded with both excellent regio- and enantioselectivity (14 examples, 87-95 % ee) to afford the desired 1,4-adducts, which were easily transformed to the corresponding aldehydes, esters, and ketones. Subsequently, this powerful methodology was therefore successfully applied in the synthesis of natural products. Furthermore, an iterative process was also disclosed leading to highly desirable 1,3-desoxypropionate skeletons (up to 94 % d.e.).
Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM-ENSCM, Ecole Nationale Supérieure de Chimie, 8 Rue de l'Ecole Normale, 34296 Montpellier Cedex 5 (France).
Sammy
S
Drissi-Amraoui
Ecole Nationale Supérieure de Chimie de Rennes, UMR CNRS 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France).
Marie S T
MS
Morin
Ecole Nationale Supérieure de Chimie de Rennes, UMR CNRS 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France).
Christophe
C
Crévisy
Ecole Nationale Supérieure de Chimie de Rennes, UMR CNRS 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France).
Olivier
O
Baslé
Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM-ENSCM, Ecole Nationale Supérieure de Chimie, 8 Rue de l'Ecole Normale, 34296 Montpellier Cedex 5 (France).
Renata
R
Marcia de Figueiredo
Ecole Nationale Supérieure de Chimie de Rennes, UMR CNRS 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France). marc.mauduit@ensc-rennes.fr.
Marc
M
Mauduit
Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM-ENSCM, Ecole Nationale Supérieure de Chimie, 8 Rue de l'Ecole Normale, 34296 Montpellier Cedex 5 (France). jean-marc.campagne@enscm.fr.
Jean-Marc
JM
Campagne
N-heterocyclic carbenes; acyl-N-methylimidazoles; asymmetric catalysis; conjugate addition; iterative processes