Reaction with alkynyl thioethers

Substituted 5-chloro-l,2,3-thiadiazoles react with simple hetero nucleophiles by displacement of the chlorine, but reaction with aryl- and alkyllithiums gives alkynyl-thioethers via attack at sulfur and then ring cleavage with loss of nitrogen. A similar ring cleavage occurs, but by a different mechanism, when the... 

An interesting approach to allenyl thioethers has been reported by Huang and Xiong, which is based on a novel three-component reaction. Treatment of 1-alkynyl-phosphine oxides 310 with lithium alkylthiolates 311 in the presence of an aldehyde 312 provides the expected highly substituted allenyl thioethers 313 in good yield (Scheme 8.84) [173]. Unfortunately, this procedure could not be extended to arylthio-lates. 

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