An Introverted Bis-Au Cavitand and Its Catalytic Dimerization of Terminal Alkynes

A preparative synthesis of an inwardly oriented phosphoramidite-Au dinuclear resorcinarene cavitand complex is described, including a description of potent catalytic abilities. The cavitand structure was determined by crystallographic analysis, which revealed that the phosphoramidite P-N bonds point outside placing the two Au atoms inside. We explored the catalytic proclivity of the cavitand and found that it effeciently catalyzes selective and direct dimerization of terminal alkynes to afford conjugated enynes. Mixed dimerizations give rise to chemoselective products, and macrocyclization by intramolecular dimerization are both trademark capabilities of the method.