Direct, catalytic monofluorination of sp³ C-H bonds: a radical-based mechanism with ionic selectivity

Cody Ross Pitts; Steven Bloom; Ryan Woltornist; Dillon Jay Auvenshine; Lev R Ryzhkov; Maxime A Siegler; Thomas Lectka

doi:10.1021/ja505136j

Direct, catalytic monofluorination of sp³ C-H bonds: a radical-based mechanism with ionic selectivity

J Am Chem Soc. 2014 Jul 9;136(27):9780-91. doi: 10.1021/ja505136j. Epub 2014 Jun 27.

Authors

Cody Ross Pitts¹, Steven Bloom, Ryan Woltornist, Dillon Jay Auvenshine, Lev R Ryzhkov, Maxime A Siegler, Thomas Lectka

Affiliation

¹ Department of Chemistry, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States.

PMID: 24943675
DOI: 10.1021/ja505136j

Abstract

Recently, our group unveiled a system in which an unusual interplay between copper(I) and Selectfluor effects mild, catalytic sp(3) C-H fluorination. Herein, we report a detailed reaction mechanism based on exhaustive EPR, (19)F NMR, UV-vis, electrochemical, kinetic, synthetic, and computational studies that, to our surprise, was revealed to be a radical chain mechanism in which copper acts as an initiator. Furthermore, we offer an explanation for the notable but curious preference for monofluorination by ascribing an ionic character to the transition state.