Environmentally benign and highly stable magnetic nano powder of NiFe₂O₄ was synthesized and characterized by XRD, HRTEM, EDX and Nitrogen BET adsorption isotherm analysis. Also, XPS analysis confirmed the electronic environment as well as the oxidation state of the elements. The NiFe₂O₄ catalyst was exploited in one‐pot three‐component synthesis of spiro[indoline‐3,3′‐pyrrolizine] and spiro[indoline‐3,5′‐pyrrolo[1,2‐c]thiazole] scaffolds, because of its ditopic nature which can provide both acidic (Fe³⁺) and basic (O²⁻) properties, require for the reactions. The desirability of this methodology resides in its simplicity, environmental friendliness, cost effectiveness and easier scaling up for bulk synthesis. Water was utilised as a medium for synthesis of the catalyst as well as the medium of the reaction leading to the product. The synthesized NiFe₂O₄ nanocatalyst can be recycled upto six times without any significant loss of activity.

中文翻译：

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磁性可回收NiFe2O4纳米催化剂的双位性质用于绿色合成两种不同的螺[吲哚啉-吡咯嗪]支架的用途

通过XRD，HRTEM，EDX和氮BET吸附等温线分析，合成了环境友好的高稳定性NiFe ₂ O ₄磁性纳米粉并进行了表征。此外，XPS分析证实了电子环境以及元素的氧化态。NiFe ₂ O ₄催化剂被用于螺[吲哚啉-3,3'-吡咯嗪]和螺[吲哚啉-3,5'-吡咯并[1,2-c]噻唑]支架的一锅三组分合成中，由于它的双位性质，可以同时提供酸性（Fe ³⁺）和碱性（O ²⁻）特性，需要进行反应。这种方法的理想之处在于它的简单性，环境友好性，成本效益以及更容易扩大规模以进行批量合成。水被用作合成催化剂的介质以及导致产物的反应的介质。合成的NiFe ₂ O ₄纳米催化剂可以循环使用六次，而活性没有任何明显的损失。