Chatterjee Anamitra, König Burkhard
Universität Regensburg, Fakultät für Chemie und Pharmazie, 93040, Regensburg, Germany.
Angew Chem Int Ed Engl. 2019 Oct 1;58(40):14289-14294. doi: 10.1002/anie.201905485. Epub 2019 Aug 27.
The direct reduction of arenes and heteroarenes by visible-light irradiation remains challenging, as the energy of a single photon is not sufficient for breaking aromatic stabilization. Shown herein is that the energy accumulation of two visible-light photons allows the dearomatization of arenes and heteroarenes. Mechanistic investigations confirm that the combination of energy-transfer and electron-transfer processes generates an arene radical anion, which is subsequently trapped by hydrogen-atom transfer and finally protonated to form the dearomatized product. The photoreduction converts planar aromatic feedstock compounds into molecular skeletons that are of use in organic synthesis.
通过可见光照射直接还原芳烃和杂芳烃仍然具有挑战性，因为单个光子的能量不足以打破芳香稳定性。本文表明，两个可见光光子的能量积累能够实现芳烃和杂芳烃的去芳构化。机理研究证实，能量转移和电子转移过程的结合产生了芳烃自由基阴离子，随后该阴离子通过氢原子转移被捕获，最终质子化形成去芳构化产物。光还原将平面芳香原料化合物转化为可用于有机合成的分子骨架。
