Organophotoredox Dioxygenation of Alkenes via ROH···F-Activated N‑Alkoxyphthalimides

TL;DR

This paper introduces a new method for converting alkenes into dialkoxylated products using light and a metal-free catalyst, offering mild conditions and high efficiency.

Contribution

A novel photoredox-catalyzed dioxygenation method using fluorinated N-alkoxyphthalimides activated by hydrogen-bonded aggregates.

Findings

The method works under mild, metal-free conditions with high functional group tolerance.

A radical/polar crossover pathway was identified through mechanistic studies.

The process is scalable and produces a diverse range of dialkoxylated products.

Abstract

The generation and
controlled reactivity of alkoxyl radicals remain
challenging due to their high energy and tendency for β-scission
or hydrogen atom transfer events. Herein, we report a photoredox-catalyzed
dioxygenation of alkenes enabled by the activation of fluorinated N-alkoxyphthalimides through hydrogen-bonded aggregates
with ROH···F. This transformation proceeds under mild,
metal-free conditions using an organophotocatalyst and a simple alcohol,
affording a diverse range of dialkoxylated products with high functional
group tolerance and good scalability. Mechanistic studiesincluding
UV–Vis spectroscopy, NMR, cyclic voltammetry, and Stern–Volmer
quenchingreveal a radical/polar crossover pathway.

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