N-Ammonium Ylide Mediators for Selective Electrochemical C–H Oxidation

The site-specific oxidation of strong C(sp3)-H bonds is of uncontested utility in organic

synthesis. From simplifying access to metabolites and late-stage diversification of lead compounds

to truncating retrosynthetic plans, there is a growing need for new reagents and methods for

achieving such a transformation in both academic and industrial circles. One main drawback of

current chemical reagents is the lack of diversity with regards to structure and reactivity that

prevent a combinatorial approach for rapid screening to be employed. In that regard, directed

evolution still holds the greatest promise for achieving complex C–H oxidations in a variety of

complex settings. Herein we present a rationally designed platform that provides a step towards

this challenge using N-ammonium ylides as electrochemically driven oxidants for site-specific,

chemoselective C(sp3)–H oxidation. By taking a first-principles approach guided by computation,

these new mediators were identified and rapidly expanded into a library using ubiquitous building

blocks and trivial synthesis techniques. The ylide-based approach to C–H oxidation exhibits

tunable selectivity that is often exclusive to this class of oxidants and can be applied to real world

problems in the agricultural and pharmaceutical sectors.