DDQ-mediated direct cross-dehydrogenative-coupling (CDC) reaction of thiols with isochroman: A serendipitous metal-free route to C-S bond formation

Abstract

A direct and efficient carbon-sulfur bond formation method was developed. For the first time, cross-dehydrogenative-coupling (CDC) reaction of an especial type of benzyl ethers (isochroman) and a variety of thiols was investigated. 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) without using any metal catalyst provides a simple and efficient method to construct C-S bond leading to the library of sulfur-containing hetrocyclic compounds. Indeed, we can directly functionalize Csp3-H bond by S-H bond without requiring pre-activation. As a result, this method will increase synthetic efficiency at the most fundamental level of organic synthesis.