Direct C–H bond arylations and alkenylations with phenol-derived fluorine-free electrophiles

Significant progress has been accomplished in direct C–H bond arylations of arenes and heteroarenes with readily accessible, inexpensive phenol derivatives. Thus, ruthenium biscarboxylate complexes and inexpensive cobalt compounds allowed for challenging C–H bond derivatizations of arenes. Further, palladium, nickel and cobalt catalysts set the stage for step-economical C–H/C–O bond functionalization with electron-rich as well as electron-deficient heteroarenes.