Synthesis of pyrrole derivatives via ring closing metathesis, Clauson‐Kaas reaction and Paal‐Knorr condensation as key steps

Abstract

Herein, we report three simple methods for the synthesis of pyrrole derivatives starting with commercially available amines. Using Grubbs first-generation catalyst (G-I) one pot ring closing metathesis (RCM) and aromatization sequence was realized to assemble pyrrole deivatives without the use of any additional reagents. The second and third methods rely on, the condensation of 2,5-hexanedione/2,5-dimethoxy tetrahydrofuran in the presence of a low melting mixture of N, N'-dimethylurea (DMU) and L-(+)-tartaric acid (TA) and glacial acetic acid to produce substituted pyrroles in excellent yield. We also studied the photophysical properties of these molecules by fluorescence spectroscopic data which possess good quantum yield (ΦF).