Gold(I)-catalysed addition of electron-rich arenes and heteroarenes to 1,6-enynes gives two different types of products by reaction of the intermediate cyclopropyl gold carbenes at the cyclopropane or at the carbene.
Gold(I)-catalysed arylation of 1,6-enynes: different site reactivity of cyclopropyl gold carbenes
Chem Commun. 2007, 698-700.