We next attempted the dehalogenation of more demanding aryl halides bearing conjugative or EDGs. The dehalogenation of 4-chlorobiphenyl (Ered = -2.43 V, Figure comparison to the spot-to-spot conversion typically observed for the other substrates. The dehalogenation of 4-iodoanisole (Ered = -2.50 V, Figure ) has been reported in the literature using PTH (with the conditions previously mentioned), giving 92% yield in 5 h under N2, or 89% in 24 h under air. Under our optimized conditions, PTH yields only 14% of the product, which is marginally better than the 7% yield achieved with DMAC-TRZ. By contrast, a progressively increasing yield from 27 to 61% was observed for the DMAC-TRZ derivatives, which was correlated to the Hammett constant (Figure ). 4CzIPN afforded similar yields to CNPh-DMAC-TRZ (58 and 61%, respectively).