Inter- and Intramolecular Alkyne–Carbonyl Metathesis/1,6-Addition/Oxidative Aromatization Tandem Reactions between 1,6-Diynes and Aldehydes

We report an efficient synthetic route to 9-arylfluorenes and biaryl compounds from 1,6-diynes and aldehydes via inter- and intramolecular alkyne–carbonyl metathesis/1,6-addition/oxidative aromatization reactions. These tandem reactions are initiated by a BF3·Et2O-promoted tandem inter- and intramolecular alkyne–carbonyl metathesis of 1,6-diynes with carbonyl compounds followed by an In(OTf)3-catalyzed 1,6-addition/oxidative aromatization with iodobenzene diacetate.