Cu(I)-Catalyzed 1,2-Alkynyl-propargylation and -benzylation of Benzyne Derivatives

We
report here a three-component, Cu­(I)-catalyzed hexadehydro-Diels–Alder
(HDDA) benzyne 1,2-difunctionalization reaction. This protocol allowed
the introduction of two different carbon-based substituents onto the
in situ-generated benzyne. These substituents were terminal monoynes
or diynes partnered with propargylic, benzylic, or allylic chlorides.
An example of a sequential HDDA reaction is demonstrated using the
product of a 1,3-diyne and a propargylic halide, itself a newly created
HDDA precursor.