A solvent-free synthesis of ethyl 3,5-diaryl-1H-pyrrole-2-carboxylates via triethylphosphite mediated reductive cyclization of ethyl 2-nitro-5-oxo-3,5-diarylpentanoates under microwave irradiation

Active methylenes in the synthesis of a pyrrole motif: an imperative structural unit of pharmaceuticals, natural products and optoelectronic materials

“…Epitomizing the scope and versatility of Zard et al's concept of intramolecular trapping of the imine intermediate to give pyrrole system, Kapoor et al in 2013 reported the use of triethylphosphite (P{OEt} 3 ) as a reductive cyclizing agent for the synthesis of 2,3,5-trisubstituted-1H-pyrroles from g-nitroketones 57 under microwave irradiation (Scheme 38). 99 They developed an efficient two-step synthesis of ethyl 3,5-disubstituted-1H-pyrrole-2-carboxylates that involved microwaveassisted reductive cyclization of ethyl 2-nitro-5-oxo-3,5disubstituted pentanoates (g-nitroketones 57) with triethylphosphite, which in turn, were synthesized from 1,3disubstituted-2-propen-1-ones and ethyl 2-nitroacetate following Davey and Tivey procedure 100 using diethylamine in reuxing EtOH. The integrity of the proposed mechanism was established by 31…”

Molecular docking study and molecular dynamics simulation of ethyl 3,5‐diphenyl‐1H‐pyrrole‐2‐carboxylate and (Z)‐ethyl‐2‐(3‐oxo‐1,3‐diphenylprop‐1‐enylamino)acetate

“…3,5-Disubstituted-1H-pyrrole-2carboxylate was synthesized within the literature by microwave irradiation of one,3-disubstituted propene-2-on and alkyl group nitroacetate within the presence of diethylamine (Et 2 NH) and triethylphosphite (P(OEt) 3 ) [4]. Another technique is that the treatment of ethyl-2-nitro-5-oxo-3,5diarylpentanoate with triethylphosphite beneath microwave irradiation [5]. Imbri et al obtained pyrrole-2-carboxypyrroles by electrocyclic ring closure of chalcones and glycine esters or amides [6].…”

“…[ 5 ] Another technique is the treatment of ethyl‐2‐nitro‐5‐oxo‐3,5‐diarylpentanoate with triethylphosphite beneath microwave irradiation. [ 6 ] Imbri et al obtained pyrrole‐2‐carboxypyrroles by electrocyclic ring closure of chalcones and glycine esters or amides. [ 7 ] They used a copper (II) catalyst for this reaction.…”

“…irradiation. [6] Imbri et al obtained pyrrole-2-carboxypyrroles by electrocyclic ring closure of chalcones and glycine esters or amides. [7] They used a copper (II) catalyst for this reaction.…”