A modification of the Sonogoshira coupling reaction employing an amidine base and a substoichiometric amount of water generates symmetrical and unsymmetrical bisarylethynylenes in one pot through in situ deprotection of trimethylsilylethynylene-added intermediates.

Polyphenylalkyne derivativesPolyphenylalkyne derivatives Q 0750One-Pot Synthesis of Symmetrical and Unsymmetrical Bisarylethynes by a Modification of the Sonogashira Coupling Reaction. -The modified Sonogashira reaction employs an amidine base and a substoichiometric amount of water (40 mol%) to provide the title compounds in one-pot through in situ desilylation of intermediately formed silylated alkynes. The latter are derived from aryl halides or triflates and ethynylsilane (II). The method is applied to the synthesis of oligomeric structures (XI) and (XIII). -(MIO, M. J.; KOPEL, L. C.; BRAUN, J. B.; GADZIKWA, T. L.; HULL, K. L.; BRISBOIS*, R. G.; MARKWORTH, C. J.; GRIECO, P. A.; Org. Lett. 4 (2002) 19, 3199-3202; Dep. Chem., Macalester Coll., St. Paul, MN 55105, USA; Eng.) -Klein 03-085