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Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
Photochemical generation of six- and five-membered cyclic vinyl cations
Micha Slegt1, Roel Gronheid, Dennis van der Vlugt
1Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Abstract:
The photochemical solvolyses of 4-tert-butylcyclohex-1-enyl(phenyl)iodonium tetrafluoroborate (1) and cyclopent-1-enyl(phenyl)iodonium tetrafluoroborate (2) in methanol yield vinylic ethers and vinylic cycloalkenyliodobenzenes and cycloalkenylbenzene, which are the trapping products of the geometrically destabilized C6-ring and C5-ring vinyl cation with the solvent and with the leaving group iodobenzene. Iodonium salt 2 also yields an allylic ether and allylic cyclopentenyliodobenzenes and cyclopentenylbenzene, which are the trapping products of the C5-ring allylic cation produced from the C5-ring vinyl cation by a hydride shift in a typical carbocationic rearrangement.
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