Microwave‐assisted One‐pot, Three‐component Regiospecific and Sterospecific Synthesis of Spiro Indanone Pyrrolidine/Piperidine Fused Nitrochromene Derivatives Through 1,3‐Dipolar Cycloaddition Reactions

Abstract

A simple, straightforward, and versatile protocol for the synthesis of spiro indanone pyrrolidine/piperidine fused nitrochromene derivatives is described. The synthesis of a new series of spirocyclic molecules has been expediently accomplished via a one‐pot, three component 1,3‐dipolar cycloaddition reaction. 2‐Phenyl‐nitrochromene dipolarophiles were reacted with azomethine ylides, generated in situ by the condensation of dicarbonyl compound indane‐1,3‐dione and secondary amino acid (L‐proline/pipecolic acid), to produce the corresponding cycloadducts in good yields (85–90%) under classical as well as under microwave irradiation. The cycloaddition reaction was found to be highly regiospecific and diasterospecific. The regiochemical and sterochemical outcome of the cycloaddition reaction is ascertained by 2D NMR (COSY and NOESY) studies.

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

“…[49,51] Characterization of all the synthesized chromene-fused pyrrole derivatives established by 1 H, 13 C NMR, and mass spectrometry. During initial studies, we have synthesized various substituted 3nitro-2-phenyl-2H-chromenes 12(a-m) following an effective two-component method by salicylaldehyde 10(a-j), trans-β-nitrostyrene 11 and DABCO as a catalyst in neat condition with excellent yield (83%-94%) (Scheme 1).…”

“…The above synthetic method follows oxa-Michael-Aldol condensation reaction. [49,51] Characterization of all the synthesized chromene-fused pyrrole derivatives established by 1 H, 13 C NMR, and mass spectrometry.…”

“…[45,46] With the extension of our current work, [22,[47][48][49][50] considering the importance in addition to potency of pyrrole as well as 2H-chromene molecules, we have shaped a strategy for promising molecules. Because of this advantage, this technique has gained much more significance in the field of synthetic as well as medicinal chemistry.…”

“…Because of this advantage, this technique has gained much more significance in the field of synthetic as well as medicinal chemistry. [45,46] With the extension of our current work, [22,[47][48][49][50] considering the importance in addition to potency of pyrrole as well as 2H-chromene molecules, we have shaped a strategy for promising molecules. From the structureactivity relationship (SAR) studies, a new scaffold was designed containing both 2H-chromene as well as pyrrole subunits ( Figure 2).…”

Microwave assisted synthesis of five membered nitrogen heterocycles

“…Before that in the same year they proposed a microwave assisted reaction protocol for the synthesis of spiro indanone pyrrolidine/piperidine fused nitrochromene derivatives 54 (Scheme 17). 26 It is a one pot, three component (2-phenyl-3nitrochromenes 53, indane-1,3-dione 32, and proline/pipecolic acid 49) reaction and from the substrate scope studies under optimized condition (49 (1 mmol), 53 (1 mmol), 32 (1 mmol) in EtOH (2 mL), MW irradiation (100 W power) at 80 C for 5-10 min) it is clear that microwave assisted reaction is more regio-specic and diastereospecic, affording high yield in less reaction time as compared to the conventional heating method.…”