Direct Photochemical Synthesis of Substituted Benzo[]fluorenes.

We report a new and straightforward route toward substituted benzo[]fluorenes via the direct photochemical conversion of alkynylated chalcones. This transformation exploits a high-power light-emitting diode emitting ultraviolet A light to enable the rapid formation of the target products ( = 5 min). A continuous flow approach thereby facilitates reproducibility and scalability, granting streamlined access to these important scaffolds and their derivatives.

Telescoped Flow Synthesis of Azacyclic Scaffolds Exploiting the Chromoselective Photolysis of Vinyl Azides and Azirines.

An efficient chromoselective photochemical process is presented for the synthesis of 2H-azirines and 1,3-diazabicylo[3.1.0]hex-3-enes from readily available vinyl azides.

Consecutive photochemical reactions enabled by a dual flow reactor coil strategy.

The application of a dual reactor coil for consecutive photochemical reactions is presented in continuous flow mode. This strategy enables for the first time the use of a single LED-based light source to perform two distinct photochemical reactions in an uninterrupted fashion. This approach is demonstrated for the telescoped synthesis and functionalisation of drug-like quinolines and compared to alternatives exploiting two photochemical reactor set-ups operated in sequence.