title: Transformations of Ferric Chloride-Generated Stilbene Cation Radicals. The Effect of Aromatic Substitution and a Comparison with Anodic Oxidation.
abstract: A systematic study on the FeCl3-induced oxidation of 1,2-diarylalkenes was carried out with the focus on the variation of product type as a function of aromatic substitution, as well as to compare the reactivity of stilbene cation radicals generated via Fe(III) oxidation with those generated by anodic oxidation. The aromatic substituents were found to fall into three main categories, namely those that give rise to tetralins and/or dehydrotetralins, those that give products possessing pallidol and ampelopsin F-type carbon skeletons, and last, those that give rise to trimeric products, indanes, and dehydrotetralins/tetralins. The latter are those stilbenes with a para-methoxy substituent in one ring and a para- or meta-EWG (CF3, NO2, Cl, F) in the other, and represent the most prominent departure when compared with the behavior of the same stilbenes under the conditions of anodic oxidation. Reaction pathways to rationalize the formation of the different products are presented.
authors.affiliation: Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Fong-Jiao
authors.initials: FJ
authors.lastname: Hong
authors.affiliation: Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Kam-Weng
authors.initials: KW
authors.lastname: Chong
authors.affiliation: Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Yun-Yee
authors.initials: YY
authors.lastname: Low
authors.affiliation: Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Noel F
authors.initials: NF
authors.lastname: Thomas
authors.affiliation: Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia. tskam@um.edu.my.
authors.forename: Toh-Seok
authors.initials: TS
authors.lastname: Kam
mesh_terms: D002712:Chlorides / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013267:Stilbenes / Q000737:chemistry*
chemical_list: D002712:Chlorides; D005290:Ferric Compounds; D013267:Stilbenes; C024555:ferric chloride
keywords: X-ray structures; ferric chloride oxidation; stilbene cation radicals; substituted stilbenes; trimers