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Updated: Jun 4, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Generation of medium-ring cycloalkynes by ring expansion of vinylogous acyl triflates
Jumreang Tummatorn1, Gregory B Dudley
1Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States.
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.
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