An Organometallic Umpolung Approach for Iron‐Mediated Propargylic C–H Etherification

Abstract

The synthesis of propargyl ethers is an efficient way to access a variety of pharmaceuticals and natural products. However, direct etherification of simple alkynes via propargylic C–H activation remains largely underreported, while propargylic substitution of prefunctionalized alkyne starting materials remains the dominant method for the synthesis of propargyl ethers. Herein, we report an organometallic umpolung approach for iron‐mediated C–H propargylic etherification. The stepwise iron‐mediated C–H activation followed by mild oxidative functionalization enables the first use of unadorned alkynes to preferentially couple with alcohols for the efficient synthesis of synthetically important propargylic ethers with excellent functional group compatibility, chemoselectivity and regioselectivity.