Site-Selective Photobromination of O-Acetylated Carbohydrates in Benzotrifluoride

Org Lett. 2024 Jul 19;26(28):5956-5960. doi: 10.1021/acs.orglett.4c01898. Epub 2024 Jul 8.

Abstract

Ferrier photobromination enables direct synthetic access to valuable 5-C-bromosugars but has limitations that restrict its broader use. The reaction is typically conducted in CCl4 heated at reflux with irradiation by broad spectrum, energy-inefficient heat lamps. Herein, we demonstrate that the reaction proceeds rapidly and efficiently with PhCF3 as a safe and environmentally benign alternative to CCl4 at mild temperatures (≤40 °C) inside a compact photoreactor fitted with purple light-emitting diodes (LEDs).