Head-to-head homo-coupling of arylethynes catalysed by (Dicarbonyl)ruthenium chloride metallacycles:: Selective synthesis of (E)-1,4-Diarylbut-1-en-3-ynes

Exposure of various arylethynes to catalytic amounts of dimeric ruthenacycles containing the chloro(dicarbonyl)ruthenium [Ru(CO)(2)Cl] motif efficiently and selectively leads to the formation of (E)-1,4-diaryl-but-l-en-3-ynes that result from head-to-head C-C coupling.