The manganese-catalyzed dehydrative [2+ 2+ 2] annulation reaction of a 1, 3-dicarbonyl compound and a terminal alkyne provides an efficient and regioselective synthesis of a substituted benzene derivative, highlighted by the exclusive formation of ap-terphenyl derivative from an aryl acetylene. The mechanism and the origin of the regioselectivity of the reaction were explored by experiments and density functional theory (DFT) calculations. ...
[Funk, Raymond L.; Fitzgerald, John F.; Olmstead, Thomas A.; Para, Kim S.; Wos, John A. Journal of the American Chemical Society, 1993 , vol. 115, # 19 p. 8849 - 8850]