Rhodium(I)-catalysed dimerisation of terminal acetylenes at ambient temperature and pressure

Abstract

Oct-1-yne is smoothly dimerised by the complex [RhCl(PPh₃)₃] at room temperature to give the branched chain isomer, 7-methylenepentadec-8-yne, as the main product. Other alkynes behave similarly. Phenylacetyene gives E-1,4-diphenylbutenyne and the unstable 1,3-diphenylbutenyne which reacts further to form oligomeric products.