Diametric calix[6]arene gold(I) catalysts for intramolecular cyclopropanations of 1,6-dienynes.

We report a solid-state structural investigation of diametric calix[6]arene-based phosphine gold(I) cavitands which are characterised by two specific, different 1,2,3-alternate conformations in solution and in the solid state. The effect of the specific orientation of phosphines, with respect to macrocycles, was studied in intramolecular cyclopropanation of 1,6-dienynes. The general applicability of these catalysts was disclosed, delivering a family of polycycles with high yields and functional group tolerance.