Catalyst-Free, Visible-Light Promoted One-Pot Synthesis of Spirooxindole-Pyran Derivatives in Aqueous Ethyl Lactate

Abstract

A highly efficient, eco-friendly protocol has been developed for synthesis of spirooxindole-pyran derivatives via one-pot, three-component reaction of isatins, malononitrile, and enolizable C–H activated compounds (2-hydroxynaphthalene-1,4-dione, 4-hydroxycoumarine and dimedone) under visible-light irradiation in water-ethyl lactate at room temperature. The reported approach shows significant advantages such as a high yield, mild and clean reaction conditions, the application of clean visible light as a source of energy, the absence of catalyst, the use of ethyl lactate/water as an environmentally friendly solvent, a one-pot multicomponent reaction at room temperature, no chromatographic separation, and applicability for large-scale synthesis.

An Efficient Ni/Pd Catalyzed Chemoselective Synthesis of 1,3,2‐Benzodiazaborininones from Boronic Acids and Anthranilamides

“…[11] This method requires high temperature and the yield is not ideal. Based on our tremendous interest in developing of environmentally friendly approaches for various organic transformations, [13] herein, we report an efficient strategy for the synthesis of 1,3,2benzodiazaborininones utilizing a Pd/Ni cocatalyst at room temperature (Scheme 1). [12] Although this method represents important advances, the established protocol does not sufficiently meet the demands for green chemistry and still suffers from several limitations, such as: 1) high energy consumption under harsh reaction conditions; 2) the substrates are not commercially available and expensive; 3) the reaction time is too long.…”

“…Therefore, in order to further improve the reaction efficiency, the search for a more mild and practical method with high generality for synthesis of 1,3,2-benzodiazaborininones under mild reaction conditions remains appealing and challenging. Based on our tremendous interest in developing of environmentally friendly approaches for various organic transformations, [13] herein, we report an efficient strategy for the synthesis of 1,3,2benzodiazaborininones utilizing a Pd/Ni cocatalyst at room temperature (Scheme 1).…”

Biosynthesis of Fe3O4‐magnetic nanoparticles using clover leaf aqueous extract: Green synthesis of 1,3‐benzoxazole derivatives

“…Meanwhile, multicomponent reactions (MCRs), in which three or more reactants react together in a one‐pot process to form a new product with essentially all of the atoms of the starting materials incorporated without intermediary purification, are becoming important tools for the rapid and efficient construction of structurally diverse and complex molecules. MCRs offer significant advantages over conventional linear‐type synthesis as they have all features that contribute to an ideal synthesis, such as high atom economy and bond‐forming efficiency, waste prevention, quick and simple implementation, solvents, reagents, and time and energy saving as well as avoidance of complex purification procedures . In heterocyclic compounds, oxazoles are important scaffolds that are naturally found in pharmacologically active compounds.…”

Meglumine Promoted Strategy: Environmentally Benign Protocol towards the Synthesis of Polysubstituted 2‐Aminopyrroles in Aqueous Condition

“…MCRs have proven to be more powerful and superior to classical multistep approaches because it can shorten the reaction time, improve the atom economy, reduce the separation steps, operational simplicity as well as give usual excellent productivity . Moreover, MCRs are environmentally friendly and have simpler and cheaper purification technique . Over the past decade, there have been many new three‐ and four‐component reaction methods developed and it is still meaningful to discover and develop libraries of biologically active compounds …”