(2 equiv.) and DIPEA (1 equiv.) using 402 nm irradiation for 16 h. Control experiments in the absence of DIPEA (no product formation observed) or without the Lewis Acid (lower conversion noted) support the hypothesis (Figure , part 4). Further experimental proof of ConPET stems from a near quadratic dependency of the product formation and irradiation intensity (Figure , part 6). By doubling the irradiation intensity, the product formation was quadrupled. This supports the two-photon excitation which is necessary for a ConPET mechanism to occur.