title: Catalytic Enantioselective Synthesis of C1- and C2-Symmetric Spirobiindanones through Counterion-Directed Enolate C-Acylation.
abstract: A catalytic enantioselective route to C1- and C2-symmetric 2,2'-spirobiindanones has been realized through an intramolecular enolate C-acylation. This reaction employs a chiral ammonium counterion to direct the acylation of an in situ generated ketone enolate with a pentafluorophenyl ester. This reaction constitutes the first example of a direct catalytic enantioselective C-acylation of a ketone and provides an efficient and highly enantioselective route to axially chiral spirobiindanediones. These products can be diastereoselectively derivatized, offering access to a range of functionalized spirocyclic architectures.
authors.affiliation: Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Rahemtulla
authors.affiliation: GlaxoSmithKline Pharmaceuticals, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK.
authors.forename: Hugh F
authors.initials: HF
authors.lastname: Clark
authors.affiliation: Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK. martin.smith@chem.ox.ac.uk.
authors.forename: Martin D
authors.identifier: 0000-0002-8849-488X
authors.initials: MD
authors.lastname: Smith
keywords: C-acylation; axial chirality; counterion; enantioselective synthesis; organocatalysis; phase-transfer