Activated Phenacenes from Phenylenes by Nickel-Catalyzed Alkyne Cycloadditions


  • This work was supported by the NSF (CHE-0907800; K.P.C.V.; STC MDITR, DMR-0120967, PREM DMR-0934212; T.V.T.), and CRIHAN (project 2006-013; V.G.). We acknowledge illuminating comments from Prof. R. G. Bergman.


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Going zigzag, helical, or in-between: Angular phenylenes show a propensity for adding alkynes from the bay region in processes catalyzed by [Ni(cod)(PMe3)2] (see scheme). These transformations generate novel strain- and electronically activated phenacenes. Mechanistic studies in conjunction with DFT calculations (R=Ph) provide a plausible mechanistic picture.