title: Versatile iridicycle catalysts for highly efficient and chemoselective transfer hydrogenation of carbonyl compounds in water.
abstract: Cyclometalated iridium complexes are shown to be highly efficient and chemoselective catalysts for the transfer hydrogenation of a wide range of carbonyl groups with formic acid in water. Examples include α-substituted ketones (α-ether, α-halo, α-hydroxy, α-amino, α-nitrile or α-ester), α-keto esters, β-keto esters and α,β-unsaturated aldehydes. The reduction was carried out at substrate/catalyst ratios of up to 50 000 at pH 4.5 and required no organic solvent. The protocol provides a practical, easy and efficient way for the synthesis of β-functionalised secondary alcohols, such as β-hydroxyethers, β-hydroxyamines and β-hydroxyhalo compounds, which are valuable intermediates in pharmaceutical, fine chemical, perfume and agrochemical synthesis.
authors.affiliation: Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD (UK) http://pcwww.liv.ac.uk/∼jxiao.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Talwar
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wu
authors.forename: Ourida
authors.initials: O
authors.lastname: Saidi
authors.forename: Noemí Poyatos
authors.initials: NP
authors.lastname: Salguero
authors.forename: Jianliang
authors.initials: J
authors.lastname: Xiao
keywords: carbonyl groups; cyclometalated complexes; iridium; transfer hydrogenation; water