Photoinduced Intermolecular Hydroamination and Hydroetherification of Electron-Rich Alkenes With Low Catalyst Loadings

A photochemical method based on visible-light irradiation (blue LEDs/sunlight) has been developed for the intermolecular hydroamination and hydroetherification of electron-rich alkenes. This photochemical method is compatible with a wide range of azoles and electron-rich alkenes, such as vinyl ethers, vinyl sulfides and enamides, and is performed with low concentrations of photocatalyst (1000 ppm). Comprehensive mechanistic studies indicate that this process is initiated by the formation of an active radical cation intermediate through single electron oxidation of azole, which is mediated by excited Acr-Mes+ BF4 -.

Divergent Functionalization of Alkynes Enabled by Organic Photoredox Catalysis

Direct functionalization of alkynes under oxidative conditions is challenging, as alkynes are usually recalcitrant towards typical oxidants. Herein, we communicate a strategy for the divergent functionalization of alkynes with photoexcited acridinium organic dyes, presumably via the formation of vinyl cation radicals as key intermediates. Based on the nature of the nucleophiles, different types of difunctionalized products were obtained in moderate to good yields. Addition of lithium Lewis acids resulted in a surprising reversal of diastereocontrol.