Whereas canonical strategies relying on late-stage heterocycle synthesis are typically restricted to constructing 2substituted heterocycles on four-membered ring scaffolds (Figure ), this approach enables a near limitless variety of options for (hetero)aryl incorporation. To put the current findings in context, a comparison with reported conditions for coupling of tertiary acids under photochemical activation provided no product in seven cases (0% of 25, 65, 75, 77, 81, 84 and 86).