title: Divergent reaction pathways of a cationic intermediate: rearrangement and cyclization of 2-substituted furyl and benzofuryl enones catalyzed by iridium(III).
abstract: In contrast to 2-substituted pyrrole enones, furyl and benzofuryl enones do not undergo the Nazarov electrocyclization. Instead, these furyl and benzofuryl enones exhibit unusual rearrangement sequences in the presence of catalytic amounts of [IrBr(CO)(DIM)((R)-(+)-BINAP)](SbF(6))(2) (1; DIM = diethylisopropylidene malonate) and AgSbF(6) (1:1). A 1,2-H shift followed by intramolecular Friedel-Crafts alkylation leads to synthetically valuable cyclohexanones with furanylic quaternary centers. The electrophilicity of 1 is essential for this rearrangement.
authors.affiliation: Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
authors.forename: Tulaza
authors.initials: T
authors.lastname: Vaidya
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Manbeck
authors.forename: Sylvia
authors.initials: S
authors.lastname: Chen
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Frontier
authors.forename: Richard
authors.initials: R
authors.lastname: Eisenberg