NbCl5 as Catalyst in Diels-Alder Reaction of Furan Ring

Alvaro C Neto,Deborah A Dos Santos,Ludmila R Rodrigues,Reginaldo B Dos Santos,Sandro J Greco,Valdemar Lacerda Jr

doi:10.5151/chempro-15bmos-bmos2013_201387221042

Abstract

Figure 1. Natural products deriving from 7-oxanorbonene. It is reported that uncatalyzed Diels-Alder reactions of furan take several weeks to give low yields due to diene’s low reactivity. The use of Lewis acid catalysts or high pressures are described as efficient methods to improve reaction yields. Niobium compounds have been used as catalyst in various organic reactions and provided excellent yields with good selectivity in some cases. In this study, we describe our investigations on the use of niobium pentachloride (NbCl5) as catalyst in Diels-Alder reactions between furan and some reactive dienophiles.

Highlights

Diels-Alder reaction of furan as diene provides an important intermediate — 7-oxanorbonene (1) — which is the precursor in the synthesis of many natural products such as terpene (2) and prostaglandin (3) analogues (Figure 1).[1] spectroscopic methods
It is reported that uncatalyzed Diels-Alder reactions of furan take several weeks to give low yields due to diene’s low reactivity
We describe our investigations on the use of niobium pentachloride (NbCl5) as catalyst in Diels-Alder reactions between furan and some reactive dienophiles

Summary

Introduction

Diels-Alder reaction of furan as diene provides an important intermediate — 7-oxanorbonene (1) — which is the precursor in the synthesis of many natural products such as terpene (2) and prostaglandin (3) analogues (Figure 1).[1] spectroscopic methods. Laboratório de Síntese Orgânica e Medicinal – LSO&M, Universidade Federal do Espírito Santo, Vitória-ES, Brazil. The endo:exo ratio was determined through 1H NMR integration values. It is reported that uncatalyzed Diels-Alder reactions of furan take several weeks to give low yields due to diene’s low reactivity.

Results

Conclusion