title: Vanadyl species-catalyzed complementary β-oxidative carbonylation of styrene derivatives with aldehydes.
abstract: A series of oxometallic species and metal acetylacetonates (acac) was examined as catalysts for oxidative carbonylation of styrene with benzaldehyde using t-butylhydroperoxide as the co-oxidant in warm acetonitrile. Among them, VO((acac)2 and vanadyl(IV) chloride were found to be the only catalyst class to achieve cross-coupling processes by judiciously tuning the ligand electronic attributes, leading to β-hydroxylation- and β-peroxidation-carbonylation of styrene, respectively, in a complementary manner. Mechanistic studies indicated that vanadyl-associated acyl radicals generated by t-butoxy radical-assisted, homolytic cleavage of the aldehyde C-H bond were involved in tandem processes with an exclusive syn diastereoselectivity in the case of β-methylstyrene.
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan. ctchen@mx.nthu.edu.tw.
authors.forename: Wen-Chieh
authors.initials: WC
authors.lastname: Yang
authors.forename: Shiue-Shien
authors.initials: SS
authors.lastname: Weng
authors.forename: Anandhan
authors.initials: A
authors.lastname: Ramasamy
authors.forename: Gobi
authors.initials: G
authors.lastname: Rajeshwaren
authors.forename: Yi-Ya
authors.initials: YY
authors.lastname: Liao
authors.forename: Chien-Tien
authors.initials: CT
authors.lastname: Chen