Visible-Light Induced Generation of Bifunctional Nitrogen-Centered Radicals: A Concise Synthetic Strategy to Construct Bicyclo-[3.2.1]octane and Azepane Cores 

Wan-Lei Yu, Hao-Wen Jiang, Lei Yan, Zhi-Tao Feng, Yong-Chun Luo, Pengfei Xu

https://doi.org/10.1007/s11426-020-9852-8

Abstract

A photocatalytic tandam cyclization of o-alkenylbenzaldehydes using pyridinium salts as the amination reagent is described. A variety of valuable seven-membered nitrogenous heterocyclic skeletons are prepared in modest to excellent yields in concise one-step. This transformation features mild reaction conditions and exceptional functional group tolerance. In addition, combining control experiments and DFT calculations on the mechanism can explain the reaction selectivity.