the direct functionalization of unactivated sp3 c  h bonds is still one of the most challenging problems facing synthetic organic chemists . 
 the appeal of such transformations derives from their capacity to facilitate the construction of complex organic molecules via the coupling of simple and otherwise inert building blocks , without introducing extraneous functional groups . despite notable recent efforts,1 the establishment of general and mild strategies for the engagement of sp3 c 
 h bonds in carbon 
 carbon bond forming reactions has proven difficult . within this context , the discovery of chemical transformations that are able to directly functionalize allylic methyl , methylene , and methine carbons in a catalytic manner is a priority . 
 while protocols for direct allylic c  h oxidation and amination have become widely established,2,3 the engagement of allylic substrates in carbon 
 carbon bond - forming reactions has thus far required the use of pre - functionalized coupling partners.4 in particular , the direct arylation of non - functionalized allylic systems would enable chemists to rapidly access a series of known pharmacophores , though a general solution to this longstanding challenge remains elusive . 
 we describe herein the use of both photoredox and organic catalysis to accomplish the first mild , broadly effective direct allylic c  h arylation . 
 this new c  c bond - forming reaction readily accommodates a broad range of alkene and electron - deficient arene reactants and has been used in the direct arylation of benzylic c  h bonds .