title: A natural light induced regioselective 6pi-electrocyclisation-oxidative aromatisation reaction: experimental and theoretical insights.
abstract: Stoichiometric intermolecular Pauson-Khand reactions of 4-(phenylethynyl)-6-methyl-2-pyrones with norbornene and dicobalt(0)octacarbonyl provide cyclopentenone products that undergo a facile 6pi-electrocyclisation-oxidative aromatisation transformation in the presence of natural light and oxygen, affording functionalised benzo[h]indeno[1,2-f]isochromene type products. The results are rationalised by theoretical studies, which confirm that the electrocyclisation process is favoured at C3 in the 2-pyrone ring system. The identity and precise arrangement of the 'trienyl' substituents control whether the electrocyclisation occurs in natural light.
authors.affiliation: Department of Chemistry, University of York, Heslington, York, UK.
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Moulton
authors.forename: Hao
authors.initials: H
authors.lastname: Dong
authors.forename: Ciara T
authors.initials: CT
authors.lastname: O'Brien
authors.forename: Simon B
authors.initials: SB
authors.lastname: Duckett
authors.forename: Zhenyang
authors.initials: Z
authors.lastname: Lin
authors.forename: Ian J S
authors.initials: IJ
authors.lastname: Fairlamb