Scheme 1: Scope of the photochemical nickel-catalyzed decarboxylative dehydrogenation reaction. Reactions performed on a 0.5 mmol scale. Isolated yields given and 1 H NMR yields vs. mesitylene as internal standard in parentheses. Isolated product and major isomer shown. (a) ArBr X3 was applied as aryl halide with Cs2CO3 as base. ArCl X4 was applied as aryl halide with BTMG as base. (c) No aryl halide was added.