Heterocoupling Two Similar Benzyl Radicals by Dual Photoredox/Cobalt Catalysis

作者：Wei Yang, Zhenyan Zhao, Yu Lan, Zhou Dong, Ruiying Chang, Yihang Bai, Shihan Liu, Shijun Li, Shi‐Jun Li, Linbin Niu, Linbin Niu · 发表于：Angewandte Chemie International Edition · 年份：2024 · DOI：10.1002/anie.202421256 · 被引用次数：10 · 研究领域：Radical Photochemical Reactions、Catalytic C–H Functionalization Methods、Sulfur-Based Synthesis Techniques

Transition-metal-regulated radical cross coupling enables the selective bonding of two distinct transient radicals, whereas the catalytic method for sorting two almost identical transient radicals, especially similar benzyl radicals, is still rare. Herein, we show that leveraging dual photoredox/cobalt catalysis can selectively couple two similar benzyl radicals. Using easily accessible methylarenes and phenylacetates (benzyl N-hydroxyphthalimide (NHPI) esters) as benzyl radical sources, a range of unsymmetrical 1,2-diarylethane classes via the 1°-1°, 1°-2°, 1°-3°, 2°-2°, 2°-3° and 3°-3° couplings were obtained with broad functional group tolerance. Besides the photochemical continuous flow synthesis, the one-pot procedure that directly uses phenylacetic acids and NHPI as the starting materials to avoid the pre-preparation of benzyl NHPI esters for the gram-scale synthesis is also feasible and affords good yields, showcasing the synthetic utility of our protocol.