TEMPO-Catalyzed Aerobic Oxidative Selenium Insertion Reaction: Synthesis of 3-Selenylindole Derivatives by Multicomponent Reaction of Isocyanides, Selenium Powder, Amines, and Indoles under Transition-Metal-Free Conditions

Huan Liu,Yi Fang,Shun-Yi Wang^*（汪顺义）, andShun-Jun Ji^*（纪顺俊）

Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology,Soochow University, Suzhou 215123,P. R. China

Org. Lett.,2018,20(4), 930--933

A novel and efficient approach for the selenium functionalization of indoles was developed with selenium powder as the selenium source, catalyzed by 2,2,6,6-tetramethylpiperidinooxy (TEMPO) and employing O₂as the green oxidant. This protocol provides a practical route for the synthesis of 3-selenylindole derivatives and has the advantages of readily available starting materials, mild reaction conditions, and a wide scope of substrates. Electron spin-resonance (ESR) studies reveal that the approach involves the formation of nitrogen-centered radicals and selenium radicals via oxidation ofin situgenerated selenoates.

链接：https://pubs.acs.org/doi/10.1021/acs.orglett.7b03783