Phenoxide-mediated Sonogashira coupling of trimethylsilylalkynes and aryliodides: practical synthesis of phenolic-hydroxy-substituted diarylethynes and 1,4-diarylbutadiynes

We successfully synthesized phenolic-hydroxy-substituted diarylethynes and 1,4-diarylbutadiynes from trimethylsilylalkynes and aryliodides via silyl-group-migration-induced deprotection of alkynes and the usual Sonogashira coupling. The phenol moiety, which works as a desilylating agent, can be attached to any position in the coupling partner. This improvement for Sonogashira coupling would be highly effective, especially when the coupling partner has a phenol moiety. Additionally, the stability of the migrated silyl moiety on the ethynylation of 2-iodophenol is discussed.