Enantioselective Excited-State Photoreactions Controlled by a Chiral Hydrogen-Bonding Iridium Sensitizer

• DOI: 10.1021/jacs.7b10586
• Publication Date: 2017-10-31T19:01:59Z
• Authors: Kazimer L. Skubi; Jesse B. Kidd; Hoimin Jung; Ilia A. Guzei; Mu-Hyun Baik; Tehshik P. Yoon
• Keywords: Photosensitizing Agents; Hydrogen Bonding; Stereoisomerism; Quinolones; Iridium; Ligands; Photochemical Processes; 01 natural sciences; 7. Clean energy; Catalysis; 0104 chemical sciences; Hydrogen

Stereochemical control of electronically excited states is a long-standing challenge in photochemical synthesis, and few catalytic systems that produce high enantioselectivities triplet-state photoreactions are known. We report herein an exceptionally effective chiral photocatalyst recruits prochiral quinolones using series hydrogen-bonding π–π interactions. The organization these substrates within the environment transition-metal photosensitizer leads to efficient Dexter energy transfer stereoinduction. relative insensitivity organometallic chromophores toward ligand modification enables optimization this catalyst structure for enantiomeric excess at loadings as much 100-fold lower than optimal conditions reported analogous organic photosensitizers.