title: AcOLeDMAP and BnOLeDMAP: conformationally restricted nucleophilic catalysts for enantioselective rearrangement of indolyl acetates and carbonates.
abstract: The rate of indolyl O- to C-acetyl or carboxyl rearrangement is accelerated by the electron-withdrawing N-diphenylacetyl group (DPA) using the conformationally restricted chiral catalysts AcOLeDMAP (12b) and BnOLeDMAP (13b). Highly enantioselective conversion to quaternary C-acetylated and C-carboxylated oxindoles is observed, even for substrates containing branched substituents. The rearrangement of the carboxylate substrates 19 occurs with complementary enantiofacial selectivity using catalyst 13b compared to the acetyl migrations of 16 catalyzed by 12b. Access to N-unsubstituted oxindoles is demonstrated by DPA cleavage with Et(2)NH.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Trisha A
authors.initials: TA
authors.lastname: Duffey
authors.forename: Scott A
authors.initials: SA
authors.lastname: Shaw
authors.forename: Edwin
authors.initials: E
authors.lastname: Vedejs
mesh_terms: D000085:Acetates / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry*; D002384:Catalysis; D007211:Indoles / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D000078183:Oxindoles; D011725:Pyridines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: C417980:4-(dimethylamine)pyridine; D000085:Acetates; D002254:Carbonates; D007211:Indoles; D000078183:Oxindoles; D011725:Pyridines; C022960:2-oxindole