# Recent Developments in Azomethine Ylide-Initiated Double Cycloadditions

## TL;DR

This paper reviews recent advances in using azomethine ylides for efficient synthesis of complex heterocyclic compounds.

## Contribution

The paper introduces a PASE method to improve the efficiency of double cycloadditions using azomethine ylides.

## Key findings

- AMYs are effective 1,3-dipoles for [3+2] cycloadditions in pyrrolidine synthesis.
- Double cycloadditions enable the creation of novel polyheterocyclic structures.
- The PASE method enhances reaction efficiency and green chemistry principles.

## Abstract

Azomethine ylides (AMYs) have a nitrogen–carbon double bond and an electron lone pair on the nitrogen atom. They are essential 1,3-dipoles for [3+2] cycloadditions in the synthesis of pyrrolidine-containing heterocycles. Significant progress in 1,3-diplolar cycloadditions has been made in the construction of novel heterocyclic scaffolds, with efforts to broaden substrate scope, enhance stereoselectivity, and integrate green chemistry principles. This article summarizes double cycloadditions of AMYs derived from amino esters and amino acids for the synthesis of novel polyheterocycles. The design of double cycloadditions through the pot, atom, and step economic (PASE) method to increase the reaction efficiency is discussed. The examples presented in this paper may be applied to the synthesis of biologically active molecules.