Chiral conjoined cavitands

Tetrabromocavitand bowls are converted into rim-connected hexabromodimers in one step in 17-22% yields by oxidative coupling of higher order arylcuprates. H-1 NMR and single crystal X-ray analyses of the rim-connected dimers reveal a conformationally restricted structure in which the rims of the two cavitand bowls describe planes angled at 78.8degrees to one another. Each of the two bowl cavities are occupied by a guest, in addition to being partially occluded by a portion of the complementary bowl rim. These new host compounds exhibit a very unusual form of enantioisomerism.