title: Bifunctional Brønsted Base Catalyst Enables Regio-, Diastereo-, and Enantioselective Cα-Alkylation of β-Tetralones and Related Aromatic-Ring-Fused Cycloalkanones.
abstract: The catalytic asymmetric synthesis of both α-substituted and α,α-disubstituted (quaternary) β-tetralones through direct α-functionalization of the corresponding β-tetralone precursor remains elusive. A designed Brønsted base-squaramide bifunctional catalyst promotes the conjugate addition of either unsubstituted or α-monosubstituted β-tetralones to nitroalkenes. Under these reaction conditions, not only enolization, and thus functionalization, occurs at the α-carbon atom of the β-tetralone exclusively, but adducts including all-carbon quaternary centers are also formed in highly diastereo- and enantioselective manner.
authors.affiliation: Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018, San Sebastián, Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: Urruzuno
authors.affiliation: Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018, San Sebastián, Spain.
authors.forename: Odei
authors.initials: O
authors.lastname: Mugica
authors.affiliation: Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018, San Sebastián, Spain.
authors.forename: Mikel
authors.identifier: 0000-0003-0362-0136
authors.initials: M
authors.lastname: Oiarbide
authors.affiliation: Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018, San Sebastián, Spain.
authors.forename: Claudio
authors.identifier: 0000-0001-9809-2799
authors.initials: C
authors.lastname: Palomo
keywords: Brønsted bases; heterocycles; organocatalysis; polycycles; synthetic methods