Metal‐ and Base‐Free Radical Cascade Cyclization/Hydrolysis of CN‐Containing 1,6‐Enynes with Ethers to Access Polyheterocycles

A convenient and straightforward approach for the radical cascade cyclization/hydrolysis of CN‐containing 1,6‐enynes with simple ethers under metal‐ and base‐free conditions is described. This strategy provides a variety of valuable ethers‐substituted polyheterocycles via the construction of three C−C bonds, one C=O bond, and two new six‐membered rings within a single procedure. The resulting products can smoothly undergo follow‐up conversions to various useful scaffolds. The methodology shows excellent functional group tolerance, high step‐ and atom‐ economy, and mild reaction conditions, which can be further scaled up to gram quantity in a satisfactory yield. A novel method for preparing polyheterocycles from CN‐containing 1,6‐enynes with ethers via a metal‐ and base‐free radical cascade cyclization/hydrolysis reaction has been established.