Iridium‐Catalyzed Aerobic Coupling of Salicylaldehydes with Alkynes: A Remarkable Switch of Oxacyclic Product. Issue 31 (3rd May 2018)

• Record Type: Journal Article
• Authors: Yamane, Shintaro; Hinoue, Tomoaki; Usuki, Yoshinosuke; Itazaki, Masumi; Nakazawa, Hiroshi; Hayashi, Yoshihiro; Kawauchi, Susumu; Miura, Masahiro; Satoh, Tetsuya
• Is Part Of: Chemistry. Volume 24:Issue 31(2018)
• Page Start: 7852
• Page End: 7855
• Publication Date: 2018-05-03
• Subjects: annulation -- C−H activation -- dehydrogenation -- iridium -- oxygen heterocycles; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201801245
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The iridium(III)/copper(II)‐catalyzed dehydrogenative coupling of salicylaldehydes with internal alkynes proceeds efficiently under atmospheric oxygen through aldehyde C−H bond cleavage and decarbonylation. A variety of benzofuran derivatives can be synthesized by the environmentally benign procedure. DFT calculations suggest that this unique transformation involves the facile deinsertion of CO in the key metallacycle intermediate, which is in marked contrast to the corresponding rhodium(III) catalysis that leads to CO‐retentive chromone derivatives. Abstract : Just needs a little fresh air : Construction of benzofurans was achieved through a novel iridium(III)/copper(II)‐catalyzed dehydrogenative coupling of salicylaldehydes with internal alkynes involving aldehyde C−H bond cleavage and decarbonylation. This reaction proceeds efficiently under atmospheric oxygen. To clarify the mechanism of this unique annulation, DFT calculations have been performed.