title: Exogenous-Base-Free Palladacycle-Catalyzed Highly Enantioselective Arylation of Imines with Arylboroxines.
abstract: Enantiomerically pure benzylic amines are important for the development of new drugs. A readily accessible planar-chiral ferrocene-derived palladacycle is shown to be a highly efficient catalyst for the formation of N-substituted benzylic stereocenters; this catalyst accelerates the 1,2-addition of arylboroxines to aromatic and aliphatic imines with exceptional levels of enantioselectivity. Using aldimines an exogenous base was not necessary for the activation of the boroxines, when acetate was used as an anionic ligand. Common problems such as aryl-aryl homocouplings and imine hydrolysis were fully overcome, the latter even in the absence of molecular sieves.
authors.affiliation: Universität Stuttgart, Institut für Organische Chemie, Pfaffenwaldring 55, 70569 Stuttgart (Germany).
authors.forename: Carmen
authors.initials: C
authors.lastname: Schrapel
authors.affiliation: Universität Stuttgart, Institut für Organische Chemie, Pfaffenwaldring 55, 70569 Stuttgart (Germany). rene.peters@oc.uni-stuttgart.de.
authors.forename: René
authors.initials: R
authors.lastname: Peters
mesh_terms: D000588:Amines / Q000737:chemistry*; D001593:Benzyl Compounds / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D002384:Catalysis; D005296:Ferrous Compounds; D007097:Imines / Q000737:chemistry*; D000075163:Metallocenes; D015394:Molecular Structure
chemical_list: D000588:Amines; D001593:Benzyl Compounds; D001896:Boron Compounds; D005296:Ferrous Compounds; D007097:Imines; D000075163:Metallocenes; C004998:ferrocene
keywords: 1,2-additions; boronic acids; ketimines; metallocene; transmetalation