Xu Yuan, Xianglin Yu, Kun He, Ruihan Zhang, Weilie Xiao, Jun Lin, Zhajun Zhan*, Xiaohong Cheng*, Zhihui Shao*, and Yi Jin*
Abstract
A metal-free dual C(sp3)−H bond functionalization of saturated cyclic ethers via photooxidative singlet oxygenmediated ring opening and ring closing has been developed, providing a method for generating hydrobenzofurans/pyrans/dioxins. Mechanistic studies have confirmed that ring-opening intermediates were effectively generated by singlet oxygenmediated C(sp3)−H activation and efficiently reacted with aldehydes and activated methylene compounds to form a wide array of products with high diastereoselectivities (up to >95:5 dr).This study is a rare example of α,β-dual C(sp3)−H bond functionalization of ethers.