[4 + 2] Annulation Cascades of 2-Bromo-1-arylpropan-1-ones with Terminal Alkynes Involving C-Br/C-H Functionalization.

Straightforward access to various substituted naphthalenones by copper-catalyzed [4 + 2] annulation cascades of 2-bromo-1-arylpropan-1-ones with terminal alkynes is presented. Employing a Cu(MeCN)4 PF4 catalyst and 1,10-phenanthroline (1,10-Phen) ligand enables the formation of three new C-C bonds in a single reaction via [4 + 2] annulation of a 2-bromo-1-arylpropan-1-one with an alkyne followed by α-alkylation with the other 2-bromo-1-arylpropan-1-one with excellent functional group tolerance and step efficiency.