Dinitro Anacardic Acid Copper(II) Complex—A Bio‐based Catalyst for Room Temperature Synthesis of Indolizine

Abstract This article reports the room temperature, gram‐scale synthesis of a novel, bio‐based 4’,5’‐dintro anacardic acid copper(II) complex (2 : 1 form) and its application as a homogeneous catalyst for room temperature synthesis of 1,4‐napthoquinone based indolizines. The bio‐based 4’,5’‐dinitro anacardic acid copper(II) complex was derived from cashew nut shell liquid which is a renewable but underutilized agro by‐product of the cashew industry. The synthesized copper complex was characterized through different techniques such as FT‐IR, UV, ESI‐MS, 1 H NMR, 13 C NMR, TGA, ICP‐MPAES, and HPLC analysis. To evaluate catalyst performance, the synthesis of indolizine resulting from a three component reaction of 1, 4‐naphthoquinone, pyridine, and ethyl acetoacetate was taken as a model reaction. Due to structural advantages, performance of the catalyst was excellent over the conventional copper salts in an array of green solvents. Further, the catalyst performance was tested using 3‐substituted pyridines in model reaction and gave excellent regioselectivity. This article highlights the novel applications of naturally occurring anacardic acid and its copper derivatives in organic transformations.