Homocoupling of benzyl pyridyl ethers via visible light-mediated deoxygenation

Abstract

The challenging cleavage of C–O bonds in ethers was successfully accomplished through a visible light-mediated deoxygenation process of benzyl pyridyl ethers via their corresponding pyridinium salts.

CO2-Promoted and Copper-Catalyzed Dehydroxylative Coupling of Benzylic Alcohols by the NaBH4/I2 System

“…White solid, yield: 78%, 62.4 mg; 1 H NMR (600 MHz, Chloroform- d ) δ 7.26 (d, J = 8.0 Hz, 4H), 7.08 (t, J = 8.0 Hz, 2H), 3.24 (s, 4H); 13 C­{ 1 H} NMR (151 MHz, Chloroform- d ) δ 136.8, 136.0, 128.3, 128.0, 29.8. The spectral data for this compound match that reported in the literature . HRMS (APCI), m / z : [M + H] + calcd.…”

Directing-Group-Assisted Non-Strained Ether C–O Bond Homolysis Mediated by Low-Valent Titanium

“…We underline that, even though the BDEs of C–OAr bonds are remarkably low, almost no suitable method to utilize this feature in radical C–C bond formation reactions exists. Very recently, Yang reported that the C–O bond of 2-( N -methylpyridinium) benzyl ethers can be activated by a photoredox reaction to afford benzyl radical dimers . This indicates that even with such an elaborate and reactive leaving group the ether scope is restricted to benzylic ethers.…”