Efficient solvent- and metal-free Sonogashira protocol catalysed by 1,4-diazabicyclo(2.2.2) octane (DABCO)

An efficient metal-free Sonogashira coupling protocol catalysed by DABCO is reported, where very good conversions and selectivities to the cross-coupling product were obtained under mild reaction conditions. The reported solvent-, phosphane- and metal-free protocol, that uses a cheap base as catalyst, considerably improves the green credentials of the reaction.