Photocatalytic Dehydrogenative Cross‐Coupling of Alkenes with Alcohols or Azoles without External Oxidant. Issue 4 (19th December 2016)

• Record Type: Journal Article
• Authors: Yi, Hong; Niu, Linbin; Song, Chunlan; Li, Yiying; Dou, Bowen; Singh, Atul K.; Lei, Aiwen
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 4(2017)
• Page Start: 1120
• Page End: 1124
• Publication Date: 2016-12-19
• Subjects: C−N bond formation -- C−O bond formation -- oxidant-free -- photocatalysis -- radical alkenylation; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201609274
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Direct cross‐coupling between alkenes/R‐H or alkenes/RXH is a dream reaction, especially without external oxidants. Inputting energy by photocatalysis and employing a cobalt catalyst as a two‐electron acceptor, a direct C−H/X−H cross‐coupling with H2 evolution has been achieved for C−O and C−N bond formation. A new radical alkenylation using alkene as the redox compound is presented. A wide range of aliphatic alcohols—even long chain alcohols—are tolerated well in this system, providing a new route to multi‐substituted enol ether derivatives using simple alkenes. Additionally, this protocol can also be used for N ‐vinylazole synthesis. Mechanistic insights reveal that the cobalt catalyst oxidizes the photocatalyst to revive the photocatalytic cycle. Abstract : Footloose and oxidant‐free : A photocatalytic process that employs a cobalt catalyst as an electron acceptor mediates direct C−H/X−H cross‐coupling and H2 evolution, achieving C−O and C−N bond formation.