# Visible-Light-Driven Benzylation of In Situ-Formed Imines Using Toluenes and Acridine Photocatalysis

## TL;DR

A new metal-free method uses visible light and acridine to efficiently create biologically important compounds from toluene derivatives.

## Contribution

A modular, metal-free, visible-light-driven method for synthesizing 1,2-diarylethylamines without cocatalysts.

## Key findings

- The method uses acridine photocatalysis and trifluoroacetic acid for efficient benzyl radical formation.
- The reaction is compatible with various functional groups and works well under flow conditions.
- No cocatalysts are needed for the acridine photocatalyst turnover.

## Abstract

The selective formation
of benzyl radicals through the homogeneous
photooxidation of toluene derivatives, followed by deprotonation,
is difficult to implement when the involved chemical species have
low oxidation potentials. Here, we present a successful application
of this approach for the modular construction of biologically important
1,2-diarylethylamines from toluene derivatives, aldehydes, and anilines.
This three-component reaction is driven by acridine photocatalysis
under visible light, with trifluoroacetic acid (TFA) (or p-TsOH) serving as an acid additive that plays a triple role. The
method is reliable, easy to use, metal-free, compatible with a wide
range of functional groups, and more efficient under flow conditions.
Unlike previous methods, no cocatalysts are required for the turnover
of the acridine photocatalyst.