The effects of the catalytic cavities in gold‐functionalized cavitands in the hydration of internal alkynes have been studied. Variations on cavitand structures revealed the importance of two features that were studied: (1) flanking aromatic rings, and (2) an adjacent P=O moiety. The di‐quinoxaline‐spanned resorcin[4]arene system provides a well‐defined compartment, in which a cationic Au ion activates an internal alkyne for conversion into a ketone by delivery of water that has also been activated, this time by a P=O moiety. We synthesized four variations on our parent cavitand. Variations of the cavitand walls include replacement of quinoxaline components with pyrazine or methylene units. Variation of the P=O center was accomplished with methylene or quinoxaline moieties. All variants displayed lower catalytic activity or selectivity, allowing us to confirm the significance both of an internal cavity and of an activation site for water.

Three new cis‐diquinoxaline spanned cavitands were successfully synthesized. These cis‐diphosphinated derivatives were applied in homogeneous gold‐catalyzed dimerization and hydration of alkynes as well as rhodium‐catalyzed styrene hydroformylation. The results were ranked with those obtained with their trans‐diphosphinated isomeric analogues. The structure‐activity relationship employing these two cavitands reveals that the cis‐ or trans‐positioning of the catalyst centers directly influences cooperation between the two metallic atoms to control catalytic activity, reaction profile, and product selectivity. This comparative study provides us an intellectual basis for future catalytic cavitand chemistry and homogeneous catalysis.