Acceptorless Dehydrogenative Oxidation of Secondary Alcohols Catalysed by Cp*Ir(III) -NHC Complexes.
A series of new Ir(III) complexes with carbene ligands that contain a range of benzyl wingtip groups have been prepared and fully characterised by NMR spectroscopy, HRMS, elemental analysis and X-ray diffraction. All the complexes were active in the acceptorless dehydrogenation of alcohol substrates in 2,2,2-trifluoroethanol to give the corresponding carbonyl compounds. The most active complex bore an electron-rich carbene ligand; this complex was used to catalyse the highly efficient and chemoselective dehydrogenation of a wide range of secondary alcohols to their respective ketones, with turnover numbers up to 1660. Mechanistic studies suggested that the turnover of the dehydrogenation reaction is limited by the H2 -formation step.
Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK. suleyman.gulcemal@ege.edu.tr.|Department of Chemistry, Ege University, 35100, Bornova-Izmir, Turkey. suleyman.gulcemal@ege.edu.tr.
Süleyman
S
Gülcemal
Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK.|Department of Chemistry, Ege University, 35100, Bornova-Izmir, Turkey.
Derya
D
Gülcemal
Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK.
George F S
GF
Whitehead
Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK. jxiao@liv.ac.uk.
Jianliang
J
Xiao
acceptorless dehydrogenation; alcohols; carbenes; iridium; oxidation