“Kobayashi Benzynes” as Hexadehydro-Diels–Alder Diynophiles

We
report here elaboration of a cascade strategy for naphthyne
formation using Kobayashi benzynes as diynophiles in a subsequent
in situ hexadehydro-Diels–Alder reaction. Density functional
theory computations suggest that the strained benzynes act as “super-diynophiles”
in this transformation. The reaction requires only mildly basic and
ambient temperature conditions and allows for rapid construction of
various naphthalenic products. The trapping efficiencies of several
arynophiles were determined using the benzyne to naphthyne cyclization
as an internal clock reaction.