Despite exhaustive efforts, we could not improve the conversion/yield beyond this threshold. Leveraging the facile synthetic customization of TPAs, we synthesized derivatives of TpBPA (Figure ) with electron-withdrawing groups to bolster their respective TPA .+ excited state potentials (entries 1-4). Of these, we were delighted to find that tris(4'-cyano-[1,1'-biphenyl]-4-yl)amine (TCBPA) increased the yield of 3gb to 46% (Table ). In contrast to TpBPA, the optimal TCBPA catalyst loading was 5 mol% (entries 4-8), increasing the yield of 3gb to 69% with no detected starting material (entry 6). Notably, the reaction was still quite efficient with only 1.5 mol% of TCBPA (entry 8). With these optimal conditions in hand, reactions of PhCl, benzene and even fluorobenzene were enabled, affording 3gb-3ib in modest to good (30-65%) yields (Table ).