title: Effects of Molecular Oxygen, Solvent, and Light on Iridium-Photoredox/Nickel Dual-Catalyzed Cross-Coupling Reactions.
abstract: In order to achieve reproducibility during iridium-photoredox and nickel dual-catalyzed sp(3)-sp(2) carbon-carbon bond-forming reactions, we investigated the role that molecular oxygen (O2), solvent and light-source (CF lamp or blue LED) play in a variety of Ir-photoredox mediated transformations. The presence of O2 was discovered to be important for catalyst activation when air-stable Ni(II) precatalysts were used in DMF under CF lamp irradiation; however, O2 was not required for catalysis when conducted with Ni(COD)2 in the same reaction system. O2 is believed to promote rapid reduction of the Ni(II) precatalyst by Ir(II) to Ni(0). In addition to O2, the effects that solvent and light-source have on the dual-catalyzed decarboxylative cross-coupling reactions will be discussed. These findings have enabled us to develop a more robust dual-catalyzed decarboxylative cross-coupling protocol.
authors.affiliation: †Chemistry Department (Oncology), AstraZeneca Pharmaceuticals LP, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States.
authors.forename: Martins S
authors.initials: MS
authors.lastname: Oderinde
authors.affiliation: †Chemistry Department (Oncology), AstraZeneca Pharmaceuticals LP, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States.
authors.forename: Adrian
authors.initials: A
authors.lastname: Varela-Alvarez
authors.affiliation: †Chemistry Department (Oncology), AstraZeneca Pharmaceuticals LP, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Aquila
authors.affiliation: †Chemistry Department (Oncology), AstraZeneca Pharmaceuticals LP, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Robbins
authors.affiliation: †Chemistry Department (Oncology), AstraZeneca Pharmaceuticals LP, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Johannes
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D007495:Iridium / Q000737:chemistry*; D008027:Light; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry
chemical_list: D012997:Solvents; D007495:Iridium; D002244:Carbon; D009532:Nickel; D010100:Oxygen