Palladium-catalysed Synthesis of 4-Heteroaryl and 4-Alkynyl-substituted Sydnones. 5-Oxido-3-phenyl-1,2,3-oxadiazol-3-ium-4-ylzinc Chloride

A general method is suggested for the synthesis of 4-heteroaryl- and 4-alkynyl-3-phenyl sydnones by palladium(0)-catalysed cross-coupling of 5-oxido-3-phenyl-1,2,3-oxadiazol-3-ium-4-ylcopper with heteroaryl iodides and alkynyl bromides; 5-oxido-3-phenyl-1,2,3-oxadiazol-3-ium-4-yteinc chloride has been synthesised and its reactivity investigated.