The 1H-azocino[5,4-b]indole skeleton of the lundurines has been prepared by the 8-endo-dig cyclization of an alkynylindole using AuCl3 or other gold complexes as catalysts.
Synthesis of the tetracyclic core skeleton of the lundurines by a gold-catalyzed cyclization
Tetrahedron 2009, 65, 9015-9020.