In summary, the copper mediated C(sp 2 )-H sulfonylation of aldehydes has been achieved using catalytic b-alanine to form a transient directing group. This demonstrates for the first time the potential to use a transient directing group with copper to promote C-H functionalization. The conditions were applied to a wide range of sulfinate salts and aromatic aldehydes including heteroaromatic aldehydes to effect ortho-or peri-functionalization.