Artificial photosynthesis directed toward organic synthesis

Reaction optimization Our investigations started by exploring various combinations of semiconductor photocatalysts (Fig. 2b, PC-1 and PC-2) for the three-component coupling of α-methyl styrene (1a), acetonitrile (2a), and water to furnish alcohol 3aa and H 2 . Using Ag/TiO 2 in the absence of other photocatalysts afforded 4 as the two-component adduct of 1a and 2a (14%; Entry 1), which is consistent with our previous work39. Pristine SrTiO 3 :Al in combination with Ag/TiO 2 also gave 4 (4: 15%; Entry 2), whereas RhCr/SrTiO 3 :Al selectively gave three-component-coupling product 3aa with H 2 evolution (3aa: 22%, 4: <1%, H 2 : 90 μmol; Entry 3). Meanwhile, RhCrCo/SrTiO 3 :Al drastically improved the yield of 3aa and H 2 , which were obtained along with a small amount of 5, most likely resulting from the dimerization of the benzylic radical intermediate (3aa: 72%, 5: 9%, H 2 : 160 μmol; Entry 4). Although using Pt/TiO 2 instead of RhCrCo/SrTiO 3 :Al prevented the formation of 4 and promo ... Read full article.