Copper-Catalyzed Domino Formation of (Alkynyl)bromoarenes

Significance

The authors report a mild method for the simultaneous formation of (alkynyl)bromodiarenes. In this transformation substoichiometric amounts of copper bromide catalyze the coupling of two aryne molecules with a bromoalkyne. These reactions proceed in moderate to good yield and favor the desired diaryl product (1) over the mono-aryl adduct (2). In addition to bromo­alkynes, both allyl bromides and propargylic bromides have been shown to be efficient coupling partners. The synthetic utility of the (alkynyl)bromodiarenes has also been demonstrated through a subsequent Suzuki coupling to form tetra-substituted dibenzofulvenes.