Development of a Continuous Photochemical Benzyne-Forming Process

Abstract

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.

Key words

flow chemistry - photochemistry - benzyne - cycloadditions - high-energy intermediates - reaction development - heterocycles

Publication History

Received: 23 December 2020

Accepted after revision: 07 January 2021

Article published online:
01 February 2021

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