Direct Utilization of Near-Infrared Light for Photooxidation with a Metal-Free Photocatalyst

Molecules. 2022 Jun 23;27(13):4047. doi: 10.3390/molecules27134047.

Abstract

Near-infrared (NIR) light-triggered photoredox catalysis is highly desirable because NIR light occupies almost 50% of solar energy and possesses excellent penetrating power in various media. Herein we utilize a metal-free boron dipyrromethene (BODIPY) derivative as the photocatalyst to achieve NIR light (720 nm LED)-driven oxidation of benzylamine derivatives, sulfides, and aryl boronic acids. Compared to blue light-driven photooxidation using Ru(bpy)3Cl2 as a photocatalyst, NIR light-driven photooxidation exhibited solvent independence and superior performance in large-volume (20 mL) reaction, presumably thanks to the neutral structure of a BODIPY photocatalyst and the deeper penetration depth of NIR light. We further demonstrate the application of this metal-free NIR photooxidation to prodrug activation and combination with Cu-catalysis for cross coupling reaction, exhibiting the potential of metal-free NIR photooxidation as a toolbox for organic synthesis and drug development.

Keywords: BODIPY; near-infrared light; photoredox catalysis; prodrug activation.

MeSH terms

  • Boronic Acids
  • Catalysis
  • Infrared Rays*
  • Light*
  • Oxidation-Reduction
  • Sulfides

Substances

  • Boronic Acids
  • Sulfides