title: Synthesis and Modular Reactivity of Pyrazole 5-Trifluoroborates: Intermediates for the Preparation of Fully Functionalized Pyrazoles.
abstract: The regioselective condensation of hydrazines and ynone trifluoroborates provides access to a range of pyrazole 5-trifluoroborates. The stability of the borate unit allows chemoselective halogenation of the heteroaromatic ring, thereby delivering pyrazole scaffolds that allow orthogonal functionalization at C5 and C4. The modular reactivity of these intermediates is exemplified by cross-coupling reactions, enabling regiocontrolled synthesis of fully functionalized pyrazole derivatives.
authors.affiliation: Department of Chemistry, University of Sheffield , Brook Hill, Sheffield S3 7HF, U.K.
authors.forename: Prisca
authors.initials: P
authors.lastname: Fricero
authors.affiliation: Sanofi-Aventis Deutschland GmbH, R&D , Industriepark Höchst, G838, D-65926 Frankfurt Am Main, Germany.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bialy
authors.affiliation: Department of Chemistry, University of Sheffield , Brook Hill, Sheffield S3 7HF, U.K.
authors.forename: Andrew W
authors.identifier: 0000-0001-6279-5177
authors.initials: AW
authors.lastname: Brown
authors.affiliation: Sanofi-Aventis Deutschland GmbH, R&D , Industriepark Höchst, G838, D-65926 Frankfurt Am Main, Germany.
authors.forename: Werngard
authors.initials: W
authors.lastname: Czechtizky
authors.affiliation: Sanofi-Aventis Deutschland GmbH, R&D , Industriepark Höchst, G838, D-65926 Frankfurt Am Main, Germany.
authors.forename: María
authors.initials: M
authors.lastname: Méndez
authors.affiliation: Department of Chemistry, University of Sheffield , Brook Hill, Sheffield S3 7HF, U.K.
authors.forename: Joseph P A
authors.identifier: 0000-0001-5038-5699
authors.initials: JP
authors.lastname: Harrity