Synthesis of Structurally Diverse Polyfunctional Pyrrolo[1,2‐a]quinolines by Sequential Iron‐Catalyzed Three‐Component Coupling and Gold‐Catalyzed Hydroarylation Reactions

Abstract

A simple and efficient synthesis of complex pyrrolo[1,2‐a]quinoline derivatives was achieved through sequential reactions that involved an iron(III)‐catalyzed synthesis of N‐(2‐alkynylaryl)pyrroles and a gold(III)‐catalyzed intramolecular hydroarylation reaction. This strategy tolerated a wide range of substrates with a variety of sensitive functional groups and afforded the corresponding pyrrolo[1,2‐a]quinoline derivatives in moderate to good yields. The ease of availability of the starting materials and the generality of the reaction sequences make it a highly attractive strategy to synthesize a diverse range of pyrrolo[1,2‐a]quinoline derivatives. Moreover, a preliminary photophysical study showed that the resulting molecules exhibit good fluorescence activity.

Microwave‐assisted rapid and efficient synthesis of chromene‐fused pyrrole derivatives through multicomponent reaction and evaluation of antibacterial activity with molecular docking investigation

“…Based on results mentioned above, a plausible mechanism was proposed to justify the formation of compound 1-(2-methyl-3,4-diphenyl-3,4-dihydrochromeno [3,4-b] pyrrol-1-yl)ethenone derivatives 15a shown in Scheme 2. [35]…”

“…[34][35][36][37] Various groups have reported the synthesis of coumarin-based pyrrole derivatives via multicomponent reaction. Now, one-pot multicomponent reactions (MCRs) become popular in the construction of highly complex and diverse structures of a heterocyclic compound, which appear as a vital moiety of many active molecules and natural compounds with biological properties.…”

“…Now, one-pot multicomponent reactions (MCRs) become popular in the construction of highly complex and diverse structures of a heterocyclic compound, which appear as a vital moiety of many active molecules and natural compounds with biological properties. [34][35][36][37] Various groups have reported the synthesis of coumarin-based pyrrole derivatives via multicomponent reaction. [36,[38][39][40] There are very few reports found on 2H-chromene-based pyrrole scaffold in the literature, [41][42][43][44] and this fact provided a continuous push towards the evolution of an innovative synthetic route for the preparation of 2H-chromene-fused pyrroles with the least number of synthetic steps.…”

“…Then β-enaminocarbonyl undergoes FeCl 3 catalyzed Michael addition with 3-nitro-2H-chromene 12a to produce intermediate B.Then intermediate B undergoes intramolecular cyclization and forms a dihydro pyrrole intermediate C, which on subsequent loss of water and HNO leads to the formation of desired product 15a [35]. It is a Lewis acid catalyst and activates one of the carbonyl oxygen of 1,3-dicarbonyl compound effectively.…”

Basic approaches to the synthesis of pyrrolo[1,2-a]quinolines derivatives: a review

“…A further direction of research was developed in the study of complexes of transition metals, such as Pd [23][24][25], Cu [26][27][28][29][30][31], Cu/Pd [32], Rh [33], Ir [34], Pt [35], Fe/Au [36], Sm [37], Ce [38], etc. They are used as catalysts for the derivation of pyrrolo[1,2-a]quinoline derivatives; however, despite their potential utility, none of these procedures can directly provide end products with a lack of heavy metal admixtures [39][40][41][42].…”