Observations on the enforced orthogonality concept for the synthesis of fully hindered biaryls by a tin-free intramolecular radical ipso substitution

Hindered biaryls have been simply prepared using diazonium salt precursors and an intramolecular free radical [1,5] ipso substitution protocol. The in troduction of an additional substituent ortho to the diazonium group in the sigma aryl radical donor further enforces the formation of ipso substituti on products and hence fully hindered biaryls are the favoured products.