title: Enantioselective Desymmetrization of para-Quinamines through an Aminocatalyzed Aza-Michael/Cyclization Cascade Reaction.
abstract: An unprecedented organocatalytic asymmetric desymmetrization of para-quinamines leading to functionalized hydroindoles, a common motif in many alkaloids, has been reported. The ability of diarylprolinol silyl ethers to promote iminium and enamine activation of α,β-unsaturated aldehydes in one catalytic cycle is the centerpiece of the strategy involving a challenging aza-Michael/intramolecular cyclization cascade reaction. A range of prochiral para-quinamines and α,β-unsaturated aldehydes were investigated to afford 16 examples of hydroindoles possessing four contiguous stereocenters including one quaternary carbon. The hydroindole structures include multiple orthogonal functionalities, which underwent various transformations.
authors.affiliation: Institut Lavoisier Versailles, UMR CNRS 8180, Université de Versailles-St-Quentin-en-Yvelines, 45 Avenue des États-Unis, 78035 Versailles cedex, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Pantaine
authors.affiliation: Institut Lavoisier Versailles, UMR CNRS 8180, Université de Versailles-St-Quentin-en-Yvelines, 45 Avenue des États-Unis, 78035 Versailles cedex, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Coeffard
authors.affiliation: Institut Lavoisier Versailles, UMR CNRS 8180, Université de Versailles-St-Quentin-en-Yvelines, 45 Avenue des États-Unis, 78035 Versailles cedex, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Moreau
authors.affiliation: Institut Lavoisier Versailles, UMR CNRS 8180, Université de Versailles-St-Quentin-en-Yvelines, 45 Avenue des États-Unis, 78035 Versailles cedex, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Greck