# Challenge N- versus O-six-membered annulation: FeCl3-catalyzed synthesis of heterocyclic N,O-aminals

## TL;DR

A new method using FeCl3 catalysis creates stable N,O-aminal structures from three components, offering a novel approach to heterocyclic synthesis.

## Contribution

A selective FeCl3-catalyzed intramolecular N-annulation method for synthesizing N,O-aminal scaffolds from (thio)hydantoin intermediates.

## Key findings

- A three-component reaction successfully forms heterocyclic N,O-aminal and hemiaminal scaffolds.
- FeCl3 catalysis enables selective N-annulation from key-substituted (thio)hydantoin intermediates.
- The resulting imine surrogates are stable and structurally diverse.

## Abstract

A new class of heterocyclic N,O-aminal and hemiaminal scaffolds was successfully obtained by means of a three-component reaction (3-CR) of 1,2-diaza-1,3-dienes (DDs), α-aminoacetals and iso(thio)cyanates. These stable imine surrogates are generated from key-substituted (thio)hydantoin intermediates through selective FeCl3-catalyzed intramolecular N-annulation.