title: Hydrogen-borrowing and interrupted-hydrogen-borrowing reactions of ketones and methanol catalyzed by iridium.
abstract: Reported herein is the use of catalytic [{Ir(cod)Cl}2 ] to facilitate hydrogen-borrowing reactions of ketone enolates with methanol at 65 °C. An oxygen atmosphere accelerates the process, and when combined with the use of a bulky monodentate phosphine ligand, interrupts the catalytic cycle by preventing enone reduction. Subsequent addition of pro-nucleophiles to the reaction mixture allowed a one-pot methylenation/conjugate addition protocol to be developed, which greatly expands the range of products that can be made by this methodology.
authors.affiliation: Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA (UK).
authors.forename: Di
authors.initials: D
authors.lastname: Shen
authors.forename: Darren L
authors.initials: DL
authors.lastname: Poole
authors.forename: Camilla C
authors.initials: CC
authors.lastname: Shotton
authors.forename: Anne F
authors.initials: AF
authors.lastname: Kornahrens
authors.forename: Mark P
authors.initials: MP
authors.lastname: Healy
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Donohoe
mesh_terms: D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D008745:Methylation; D010084:Oxidation-Reduction; D013696:Temperature
chemical_list: D007659:Ketones; D007495:Iridium; D006859:Hydrogen; D000432:Methanol
keywords: Michael addition; hydrogen borrowing; iridium; oxidation; synthetic methods