On the Redox Properties of the Dimers of Thiazol-2-ylidenes That Are Relevant for Radical Catalysis

Ludivine Delfau; Nadhrata Assani; Samantha Nichilo; Jacques Pecaut; Christian Philouze; Julie Broggi; David Martin; Eder Tomás-Mendivil

doi:10.1021/acsorginorgau.3c00008

On the Redox Properties of the Dimers of Thiazol-2-ylidenes That Are Relevant for Radical Catalysis

ACS Org Inorg Au. 2023 Mar 27;3(3):136-142. doi: 10.1021/acsorginorgau.3c00008. eCollection 2023 Jun 7.

Authors

Ludivine Delfau¹, Nadhrata Assani², Samantha Nichilo¹, Jacques Pecaut³, Christian Philouze¹, Julie Broggi², David Martin¹, Eder Tomás-Mendivil¹

Affiliations

¹ Univ. Grenoble Alpes, CNRS, DCM, 38000 Grenoble, France.
² Aix Marseille Univ., CNRS, Institut de Chimie Radicalaire - UMR 7273, Faculté de Pharmacie, 13005 Marseille, France.
³ Univ. Grenoble Alpes, CEA, CNRS, INAC-SyMMES, UMR 5819 38000 Grenoble, France.

Abstract

We report the isolation and study of dimers stemming from popular thiazol-2-ylidene organocatalysts. The model featuring 2,6-di(isopropyl)phenyl (Dipp) N-substituents was found to be a stronger reducing agent (E_ox = -0.8 V vs SCE) than bis(thiazol-2-ylidenes) previously studied in the literature. In addition, a remarkable potential gap between the first and second oxidation of the dimer also allows for the isolation of the corresponding air-persistent radical cation. The latter is an unexpected efficient promoter of the radical transformation of α-bromoamides into oxindoles.