Synthesis of 2-Benzylidene-3-Pyrrolines and Their Synthetic Transformation

Ming-Tsung Hsu,Shiuh-Tzung Liu,Yi-Hung Liu

doi:10.3390/reactions1020005

Ming-Tsung Hsu, Shiuh-Tzung Liu + Show 1 more

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https://doi.org/10.3390/reactions1020005

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Journal: Reactions	Publication Date: Oct 16, 2020
Citations: 3	License type: CC BY 4.0

Affiliation: National Taiwan University

Abstract

A series of benzylidene-3-pyrrolines were prepared from chalcone derivatives, arylacetylene and sulfonamide via a three-step sequence without the isolation of intermediates. Typically, the reaction of 1,3-di-p-tolylprop-2-en-1-one with lithium phenylacetylide was followed by substitution with tosylamide and then silver-catalyzed 5-exo-dig cyclization to give N-tosyl-2-benzylidene-3,5-di-p-tolyl-2,5-dihydro-1H-pyrrole with a 86% yield. Furthermore, transformation to the corresponding substituted 3-pyrrolin-2-one and pyrrole by m-chloroperbenzoic acid (mcpba)-oxidation and acid-catalyzed aromatization, respectively, was investigated.

Highlights

Both areare five-membered nitrogen-containing heterocycles, representing an Bothpyrrole pyrroleand andpyrroline pyrroline five-membered nitrogen-containing heterocycles, representing important classclass of the scaffolds occurring in nature an important of privileged the privileged scaffolds occurring in nature and pharmaceuticals examples of their biological activity are shown in
We succeeded in the preparation of 2-ylidene-3-pyrrolines via a three-step
We succeeded in the preparation of 2-ylidene-3-pyrrolines via a three-step reaction reaction without the purification of intermediates

Summary

Introduction

Both areare five-membered nitrogen-containing heterocycles, representing an Bothpyrrole pyrroleand andpyrroline pyrroline five-membered nitrogen-containing heterocycles, representing important classclass of the scaffolds occurring in nature [1,2,3][1,2,3]. The synthetic methods toleading pyrrole rings arerings well-documented, there isthere still aisdemand for developing new toand/or pyrrolepyrroline and/or pyrroline are well-documented, still a demand for developing approaches for highly substituted and functionalized compounds. New approaches for highly substituted and functionalized compounds.

Methods

Results

Conclusion