Diversity-Oriented Synthesis of Aliphatic Fluorides via Reductive C(sp3 )-C(sp3 ) Cross-Coupling Fluoroalkylation

Angew Chem Int Ed Engl. 2021 Jun 25;60(27):15020-15027. doi: 10.1002/anie.202102481. Epub 2021 Jun 1.

Abstract

Monofluorinated alkyl compounds are of great importance in pharmaceuticals, agrochemicals and materials. Herein, we describe a direct nickel-catalyzed monofluoromethylation of unactivated alkyl halides using a low-cost industrial raw material, bromofluoromethane, by demonstrating a general and efficient reductive cross-coupling of two alkyl halides. Results with 1-bromo-1-fluoroalkane also demonstrate the viability of monofluoroalkylation, which further established the first example of reductive C(sp3 )-C(sp3 ) cross-coupling fluoroalkylation. These transformations demonstrate high efficiency, mild conditions, and excellent functional-group compatibility, especially for a range of pharmaceuticals and biologically active compounds. Mechanistic studies support a radical pathway. Kinetic studies reveal that the reaction is first-order dependent on catalyst and alkyl bromide whereas the generation of monofluoroalkyl radical is not involved in the rate-determining step. This strategy provides a general and efficient method for the synthesis of aliphatic fluorides.

Keywords: late-stage fluoroalkylation; monofluoromethylation; nickel; reductive cross-coupling.

Publication types

  • Research Support, Non-U.S. Gov't