title: Oxygen switch in visible-light photoredox catalysis: radical additions and cyclizations and unexpected C-C-bond cleavage reactions.
abstract: Visible light photoredox catalyzed inter- and intramolecular C-H functionalization reactions of tertiary amines have been developed. Oxygen was found to act as chemical switch to trigger two different reaction pathways and to obtain two different types of products from the same starting material. In the absence of oxygen, the intermolecular addition of N,N-dimethyl-anilines to electron-deficient alkenes provided γ-amino nitriles in good to high yields. In the presence of oxygen, a radical addition/cyclization reaction occurred which resulted in the formation of tetrahydroquinoline derivatives in good yields under mild reaction conditions. The intramolecular version of the radical addition led to the unexpected formation of indole-3-carboxaldehyde derivatives. Mechanistic investigations of this reaction cascade uncovered a new photoredox catalyzed C-C bond cleavage reaction.
authors: RWTH Aachen University, Institute of Organic Chemistry, Landoltweg 1, D-52074 Aachen, Germany.
authors: Shaoqun
authors: S
authors: Zhu
authors: Arindam
authors: A
authors: Das
authors: Lan
authors: L
authors: Bui
authors: Hanjun
authors: H
authors: Zhou
authors: Dennis P
authors: DP
authors: Curran
authors: Magnus
authors: M
authors: Rueping
mesh_terms: D000588:Amines / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D005609:Free Radicals / Q000737:chemistry; D008027:Light; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes
chemical_list: D000588:Amines; D005609:Free Radicals; D010100:Oxygen