A novel photoinduced intermolecular 1,2-arylheteroarylation of alkenes and the efficient synthesis of valuable polyarylalkanes are reported.The reaction is operationally simple,proceeds under mild conditions and with no additional catalyst and reagents.The strategically designed radical cascade reaction is enabled by electron transfer,and involves cleavage of an inert C-C bond.The process features broad functional group compatibility as well as high product transformability.