The room-temperature oxidative C–H/C–H cross-couplings between simple arenes and alkenes, coumarins or quinones have been reported by using a highly electrophilic palladium species [Pd(TFA)2] as the catalyst and cheap (NH4)2S2O8 as the oxidant under air.
Rh-catalysed direct cyclisation of quinones with alkynes has been accomplished through C–H activation strategy.