Synthesis of Quinolinediones by Catalyst-Free Formal Aza-[3+2+1] Cycloaddition of Enaminones, Aldehydes and Meldrum's Acid

Silvio Cunha,Lourenço L B De Santana

doi:10.5935/0103-5053.20140106

Silvio Cunha, Lourenço L B De Santana

Open Access

https://doi.org/10.5935/0103-5053.20140106

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Abstract

A simple green synthesis of 4-aryl-tetrahydroquinoline-2,5-diones was developed, improving the three-component reaction of N-aryl substituted dimedone-based enaminones, aromatic aldehydes and Meldrum's acid. The method does not employ catalyst, heating or any special solvent or reaction condition, and has facile work-up and purification. Variations of enaminones and aldehydes substituents were somewhat tolerated.

Highlights

The occurrence of N-heterocycles in natural product and drug-like compounds has motivated the development of diverse approaches to their syntheses.[1]
In the course of a project aimed at the synthesis of alkaloid-like compounds to biological evaluation based on formal cycloaddition of enaminones with Michael acceptors,[4] we identified the 4-aryl-tetrahydroquinoline2,5-dione structural scaffold as synthetic target due to the potential biological activities of quinolone derivatives.[5]
We rationalized that quinolinediones can be conveniently accessed from dimedone-based enaminones as building block (Scheme 1).[6,7,8,9,10]

Summary

Introduction

The occurrence of N-heterocycles in natural product and drug-like compounds has motivated the development of diverse approaches to their syntheses.[1]. Scope of known routes to 4-aryl-tetrahydroquinoline-2,5-diones via formal azacycloaddition of dimedone-based enaminones.

Results

Conclusion