Development of a Continuous Photochemical Benzyne-Forming Process

A continuous-flow process is presented that enables the safe generation and derivatization of benzyne under photochemical conditions. This is facilitated by a new high-power LED lamp emitting light at 365 nm. The resulting flow process effectively controls the release of gaseous by-products based on an adjustable backpressure regulator and delivers a series of heterocyclic products in a short residence time of 3 minutes. The robustness of this methodology is demonstrated for the rapid generation of benzotriazoles, 2H-indazoles and various furan-derived adducts, facilitating the preparation of these important heterocyclic scaffolds via a simple and readily scalable flow protocol.

Automated summary

A new methodology utilizing a high-power LED lamp for the safe generation and derivatization of benzyne under photochemical conditions is presented. The continuous-flow process effectively controls the release of gaseous by-products and delivers a series of heterocyclic products in a short residence time. This robust methodology enables the rapid generation of important heterocyclic scaffolds through a simple and scalable flow protocol.