Halogenation of organic compounds using continuous flow and microreactor technology

Abstract

The halogenation of organic substrates is one the most important transformations in organic synthesis. The most straightforward, inexpensive and atom economic halogenations involve the use of elemental halogens (X₂) or hydrogen halides (HX). However, X₂ and HX reagents are highly reactive, toxic and corrosive materials. Halogenations using these reagents are usually very fast and exothermic reactions, in which selectivity issues occur. Using continuous flow chemistry halogenations involving X₂ and HX can be performed in a safe and controllable manner. Reagents can be accurately dosed even for gas/liquid reactions, and exotherms are easily controlled. Hazardous chemicals can be readily quenched in line avoiding any undesired exposures and significantly enhancing the process safety.