Iron-Catalyzed Intermolecular N–H Insertion Using Acceptor–Acceptor Carbenes Derived from Iodonium Ylides

TL;DR

This paper introduces a new iron-catalyzed method for efficiently inserting nitrogen into carbon-based compounds using mild conditions and readily available materials.

Contribution

The study presents a novel iron-catalyzed N–H insertion method using iodonium ylides and iron(II) triflate under mild conditions.

Findings

The method enables functionalization of various aromatic and aliphatic amines with excellent yields.

The reaction proceeds under mild conditions without requiring an inert atmosphere or anhydrous solvents.

Mechanistic studies suggest a nonradical pathway involving an iron(II)-stabilized intermediate.

Abstract

In this study, we
report a general and efficient method
for iron-catalyzed
intermolecular N–H insertion at the intercarbonylic position
of malonate reagents. Using iodonium ylides and simple iron­(II) triflate
as the catalyst, the reaction enables the functionalization of a wide
range of primary and secondary aromatic and aliphatic amines in excellent
yields. The reaction operates under exceptionally mild conditions,
without the need for an inert atmosphere or anhydrous solvents, and
proceeds in remarkably short reaction times. Mechanistic studies support
a nonradical pathway in which an iron­(II)-stabilized intermediate
having hybrid carbene/carbocationic character undergoes nucleophilic
attack by the amine.

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