Hou H, Shen X, Wang C, Zhang L, Röse P, Chen L.-A, Harms K, Marsch M, Hilt G, Meggers
E * Philipps-Universität Marburg, Germany and Xiamen University, P. R. of China
Asymmetric Photoredox Transition-Metal Catalysis Activated by Visible Light.
Nature 2015;
515: 100-103
Key words
photoredox catalysis - enantioselective alkylation - 2-acyl imidazoles - visible light
- iridium
Significance
The authors demonstrate a unique example of asymmetric redox catalysis achieved by
visible light. Two catalytic cycles are connected by the key intermediate, an iridium(III)
enolate complex, which is an active photosensitizer generated in situ.
Comment
This process provides very mild conditions and excellent yields and enantioselectivities.
The reaction proceeds via a photoredox mechanism, supported by X-ray, radical trapping,
luminescence quenching, and interval experiment analyses.
