A Strategy for Site‐ and Chemoselective C−H Alkenylation through Osmaelectrooxidative Catalysis. Issue 52 (18th November 2021)

• Record Type: Journal Article
• Authors: Choi, Isaac; Messinis, Antonis M.; Hou, Xiaoyan; Ackermann, Lutz
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 52(2021)
• Page Start: 27005
• Page End: 27012
• Publication Date: 2021-11-18
• Subjects: C−H activation -- electrocatalysis -- electrochemistry -- osmium -- selectivity; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202110616
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Herein, we disclose osmaelectrocatalyzed C−H activations that set the stage for electrooxidative alkyne annulations by benzoic acids. The osmium electrocatalysis enables site‐ and chemoselective electrooxidative C−H activations with unique levels of selectivity. The isolation of unprecedented osmium(0) and osmium(II) intermediates, along with crystallographic characterization and analyses by spectrometric and spectroscopic in operando techniques delineate a synergistic osmium redox catalyst regime. Detailed mechanistic studies revealed a facile C−H cleavage, which allows for an ample substrate scope, providing provide robust and user‐friendly access to annulated heterocycles. Abstract : The first osmium‐catalyzed electrooxidative C−H annulation is disclosed. While improved selectivities are possible, unprecedented osmium intermediates are presented along with detailed kinetic studies, which revealed the working mode of osmaelectrocatalysis.