title: Application of Visible-to-UV Photon Upconversion to Photoredox Catalysis: The Activation of Aryl Bromides.
abstract: The activation of aryl-Br bonds was achieved by sequential combination of a triplet-triplet annihilation process of the organic dyes, butane-2,3-dione and 2,5-diphenyloxazole, with a single-electron-transfer activation of aryl bromides. The photophysical and chemical steps were studied by time-resolved transient fluorescence and absorption spectroscopy with a pulsed laser, quenching experiments, and DFT calculations.
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Universitaetsstrasse 31, 93040 Regensburg (Germany).
authors.forename: Michal
authors.initials: M
authors.lastname: Majek
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitaetsstrasse 31, 93040 Regensburg (Germany).
authors.forename: Uwe
authors.initials: U
authors.lastname: Faltermeier
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitaetsstrasse 31, 93040 Regensburg (Germany).
authors.forename: Bernhard
authors.initials: B
authors.lastname: Dick
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Universitaetsstrasse 31, 93040 Regensburg (Germany). raul.perez-ruiz@ur.de.
authors.forename: Raúl
authors.initials: R
authors.lastname: Pérez-Ruiz
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Universitaetsstrasse 31, 93040 Regensburg (Germany). axel.jacobi@ur.de.
authors.forename: Axel
authors.initials: A
authors.lastname: Jacobi von Wangelin
keywords: aryl halides; defunctionalization; organocatalysis; photocatalysis; triplet states; two-photon process