title: Generation of medium-ring cycloalkynes by ring expansion of vinylogous acyl triflates.
abstract: Reductive cyclization of aryl and vinyl iodides tethered to vinylogous acyl triflates (VATs) induces a ring-expanding fragmentation to provide cyclic alkynyl ketones, including strained nine-membered cycloalkynes, in fair to excellent yield. The tandem cyclization/C-C bond-cleavage is initiated under carefully optimized conditions by halogen-metal exchange in the presence of carbonyl and vinyl triflate functionality. A modified protocol for alkylation of 1,3-cyclohexanedione is described for preparing the relevant VAT substrates.
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States.
authors.forename: Jumreang
authors.initials: J
authors.lastname: Tummatorn
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Dudley