New persubstituted 1,3,5-trisethynyl benzenes via Sonogashira coupling

Starting from 1,3,5-trifluoro-2,4,6-triiodobenzene, selective Sonogashira coupling gave trisalkynylbenzenes, which can be further functionalized making use of the reactive fluorine substituents on the benzene core. Along the way, a conceivably trivial deprotection step unexpectedly led to a pentasubstituted benzene derivative the structure of which was revealed by X-ray crystallography.