Finally, the reaction efficiency and enantioselectivity were significantly improved at 0 °C, affording (S)-4a in 77% isolated yield with 93% ee. When using the optimal ligand L10, the number of equivalents of 2-vinylnaphthalene 1a and oxime carbonate 2a relative to phenylboronic acid 3a have somewhat influence on the ratio of desired product (S)-4a and byproduct by-4a. The substrate ratio of 1a/2a/3a as 3.0:2.0:1.0 was still the best of choice (Table ). To gain some insight into this interesting phenomenon, we performed time-course studies on the model reaction with and without visible light irradiation using a combination of Cu(CH3CN)4PF6 and L10 at 0 °C (Table and). Notably, under visible light irradiation the radical precursor oxime carbonate 2a reacted faster, and a larger amount of by-product by-4a was formed, compared to the reaction performed in dark. Moreover, after 4 hours, 2a was completely consumed, thus leading to no further formation of desired product 4a. In contrast, there was a significant amount of the oxime carbonate 2a still present without visible light irradiation after 4 hours, which allowed the three-component cross-coupling to proceed further. These results suggest that rate matching between radical generation and cross-coupling is essential for the desired intermolecular three-component reaction.