The Electrosynthesis of Highly Encumbered Biaryls from Aryl o-Iodobenzyl Ethers by a Radical to Polar Crossover Sequence. Highly encumbered 2,2',6-tri- and 2,2',6,6'-tetra-substituted biaryls are readily prepared from aryl ortho-iodobenzyl ethers through mediated cathodic reduction under flow. The reaction proceeds via the stepwise transfer of two electrons: the first to induce loss of iodide and a radical cyclisation, and the second to induce a polar fragmentation.