Sulfinate‐Salt‐Mediated Radical Relay Cyclization of Cyclic Ethers with 2‐Alkynylbenzonitriles toward 3‐Alkylated 1‐Indenones

Xiao‐Tong Zhu; Tian‐Shu Zhang; Qi Zhao; Pei‐Jun Cai; Wen‐Juan Hao; Shu‐Jiang Tu; Bo Jiang

Index: 10.1002/asia.201800211

Full Text: HTML

Abstract

A new sulfinate salt‐mediated radical relay for the completion of C(sp3)−H bond indenylation of cyclic ethers with readily available 2‐alkynylbenzonitriles by combining silver/tert‐butyl peroxide (TBHP) was established, providing a wide range of 3‐alkylated 1‐indenones with generally good yields. Interestingly, the current reaction system can tolerate an S‐centered radical and a C‐centered radical in one pot, in which the S‐centered radical promotes the formation of the C‐centered radical to induce a radical cascade without disturbing the reaction process. A reaction mechanism is also proposed based on control experiments.