Cobalt-Mediated Photochemical C-H Arylation of Pyrroles.

Autor: Märsch J; Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany., Reiter S; Department of Chemistry, Ludwig Maximilian University Munich, 81377, Munich, Germany., Rittner T; Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040, Regensburg, Germany., Rodriguez-Lugo RE; Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.; present address: Istituto di Chimica dei Composti Organometallici, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, Sesto Fiorentino, 50019, Italy., Whitfield M; Department of Chemistry, Ludwig Maximilian University Munich, 81377, Munich, Germany., Scott DJ; Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.; present address: Department of Chemistry, University of Bath, Claverton Down Bath, BA2 7AY, United Kingdom., Kutta RJ; Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040, Regensburg, Germany., Nuernberger P; Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040, Regensburg, Germany., de Vivie-Riedle R; Department of Chemistry, Ludwig Maximilian University Munich, 81377, Munich, Germany., Wolf R; Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2024 Jul 08; Vol. 63 (28), pp. e202405780. Date of Electronic Publication: 2024 Jun 20.
DOI: 10.1002/anie.202405780
Abstrakt: Precious metal complexes remain ubiquitous in photoredox catalysis (PRC) despite concerted efforts to find more earth-abundant catalysts and replacements based on 3d metals in particular. Most otherwise plausible 3d metal complexes are assumed to be unsuitable due to short-lived excited states, which has led researchers to prioritize the pursuit of longer excited-state lifetimes through careful molecular design. However, we report herein that the C-H arylation of pyrroles and related substrates (which are benchmark reactions for assessing the efficacy of photoredox catalysts) can be achieved using a simple and readily accessible octahedral bis(diiminopyridine) cobalt complex, [1-Co](PF 6 ) 2 . Notably, [1-Co] 2+ efficiently functionalizes both chloro- and bromoarene substrates despite the short excited-state lifetime of the key photoexcited intermediate *[1-Co] 2+ (8 ps). We present herein the scope of this C-H arylation protocol and provide mechanistic insights derived from detailed spectroscopic and computational studies. These indicate that, despite its transient existence, reduction of *[1-Co] 2+ is facilitated via pre-assembly with the NEt 3 reductant, highlighting an alternative strategy for the future development of 3d metal-catalyzed PRC.
(© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
Databáze: MEDLINE
Externí odkaz: