title: Thermal reduction of 7H-benz[d,e]anthracen-7-one and related ketones under hydrogen-transfer conditions.
abstract: In the presence of hydrogen donor solvents and at elevated temperatures, aromatic ketones can be selectively deoxygenated to the corresponding hydroaromatic compounds. The kinetics for reduction of 7H-benz[d,e]anthracen-7-one (benzanthrone, 6) into 7H-benz[d,e]anthracene (benzanthrene, 1) in 9,10-dihydroanthracene (3) solvent has been investigated in detail. The relatively slow hydrogenation of 6 is due to reversibility of the initial hydrogen-transfer step according to a reverse radical disproportionation (RRD). The dynamics could well be rationalized using the energetics of species computed by density functional theory (DFT). The application of hydrogen donors such as 1 as a hydrogen-transfer agent, although favorable in terms of a low benzylic carbon-hydrogen bond dissociation enthalpy, is limited due to the slow self-hydrogenation, which in case of 1 gives 5,6-dihydro-4H-benz[d,e]anthracene (7).
authors.affiliation: Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands. p.mulder@chem.leidenuniv.nl
authors.forename: P
authors.initials: P
authors.lastname: Mulder
authors.forename: S
authors.initials: S
authors.lastname: Hemmink
authors.forename: M I
authors.initials: MI
authors.lastname: De Heer
authors.forename: M
authors.initials: M
authors.lastname: Lupo
authors.forename: D
authors.initials: D
authors.lastname: Santoro
authors.forename: H G
authors.initials: HG
authors.lastname: Korth