Ionic liquid accelerated multicomponent sequential assembly of ferrocene grafted spiro-heterocycles

•Reported ionic liquid used for the first time.•One step multicomponent reaction.•Solvent and column chromatography was not used for isolation.•Methodology is highly ecofriendly.

A facile one-pot synthesis of novel ferrocene grafted spiro-indenoquinoxalline pyrrolizidines/pyrrolo[1,2-c]thiazole via multicomponent [3 + 2] cycloaddition of azomethine ylides using N-(1-acroloyl)-N-(4-cyclopentyl)-piperazinium dihydrogen phosphate as ionic liquid is described. The structure of cycloadducts were confirmed by IR, 1H NMR, 13C NMR, high resolution mass spectroscopy, single crystal X-ray analysis. The ionic liquid, N-(1-acroloyl)-N-(4-cyclopentyl)-piperazinium phosphate is easy to synthesize and more specific in providing the desired product with high regioselectivity, in much shorter reaction time, higher yield and no column purification of the product is required.

Graphical abstractAn expedient ionic liquid accelerated synthesis of complex ferrocene grafted spiro-heterocycles via a sequential multicomponent [3 + 2]-cycloaddition reaction is described.Figure optionsDownload full-size imageDownload as PowerPoint slide