title: Pd(II)-catalyzed regio-, enantio-, and diastereoselective 1,4-addition of azlactones formed in situ from racemic unprotected amino acids and acetic anhydride.
abstract: A multicomponent reaction is reported generating highly enantioenriched and diastereomerically pure quaternary amino acid derivatives via 1,4-addition of azlactones to enones. The azlactone intermediates are generated in situ from unprotected α-amino acids and acetic anhydride. Previous attempts using bis-palladacycle catalysts required the use of a large excess of benzoic anhydride (which is very difficult to remove from the products), since acetic anhydride provided regioisomeric product mixtures. Key for the high regioselectivity is a pentaphenylferrocene monopalladacycle catalyst.
authors.affiliation: Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
authors.forename: Manuel
authors.initials: M
authors.lastname: Weber
authors.forename: René
authors.initials: R
authors.lastname: Peters
mesh_terms: D000089:Acetic Anhydrides / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D002384:Catalysis; D007783:Lactones / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000008:administration & dosage*; D013237:Stereoisomerism
chemical_list: D000089:Acetic Anhydrides; D000596:Amino Acids; D007783:Lactones; C031800:acetic anhydride; D010165:Palladium