4-Bromotoluene is a p-substituted aryl bromide. 4-Bromotoluene undergoes C-O coupling reaction with 2,4-dimethylphenol catalyzed by the CuI/K2CO3/phen system. Complexes [Cu(phen)(1-(2,4-dimethylphenoxy)-4-methylbenzene)]+, {H[Cu(phen)(2,4-dimethylphenoxy)]}+ and [Cu(2,4-dimethylphenoxy)2]- were reported as intermediates during the reaction by in situ electrospray ionization mass spectrometry (ESI-MS) analysis. Suzuki coupling reaction of 4-bromotoluene and non-fluorescent phenylboronic acid (PBA) in the presence of palladium (II) acetate as a catalyst has been studied. Palladium catalyzed C-N cross-coupling reaction of 4-bromotoluene with piperidine in a microstructured continuous reactor has been described. 4-Bromotoluene has been reported to undergo Heck reaction with styrene in the presence of in situ generated palladium complexes of phosphine-functionalized N-heterocyclic carbene ligands.