An efficient green chemistry protocol for the synthesis of novel spiropyrrolizidine compounds

Cu/TEMPO catalyzed dehydrogenative 1,3-dipolar cycloaddition in the synthesis of spirooxindoles as potential antidiabetic agents

“…Fokas, Lalitha and co-workers utilized a,b-unsaturated carbonyl compounds and volatile toxic solvents, alike methanol and dioxane (Scheme 1). 23,31 Consequently, in the present study envisioned the a,b-unsaturated carbonyl intermediate, 1d formation from Cu-TEMPO catalyzed dehydrogenation of the saturated ketone. TEMPO is a unique free radical (oxidant); was used as co-catalyst for several mechanistic studies.…”

“…Moreover, these spirooxindoles were generated by the decarboxylative condensation [19][20][21] of isatins and a-amino acids with unsaturated alkenes. [22][23][24] A wide variation of azomethine ylides, 25 including a-amino acids, and 1,3-dipolarophiles such as a,b-unsaturated carbonyl compounds, 26 (chalcones) arylidene-malono-dinitriles, 27 nitrostyrene, 28 acrylamides 29 a,b-unsaturated lactones, 30 and various electron-decient alkenes have been extensively documented.…”

Recent Advances in Green Synthesis of 3,3′‐Spirooxindoles via Isatin–based One–pot Multicomponent Cascade Reactions in Aqueous Medium

“…Multicomponent reactions (MCRs) are known as a kind of powerful organic synthesis reactions, in which three or more simple and readily available reactants are used as starting materials to obtain the target products in one‐pot reaction system . Multicomponent reactions allow the formation of several bonds in a single operation and offer remarkable advantages such as fewer reaction steps, operational simplicity, less energy consumption and high atom economy . These advantages have promoted the application of MCRs in the synthesis of natural products, functionally diverse molecules towards the discovery of novel biologically active compounds .…”

“…[3] Multicomponent reactions allow the formation of several bonds in a single operation and offer remarkable advantages such as fewer reaction steps, operational simplicity, less energy consumption and high atom economy. [4] These advantages have promoted the application of MCRs in the synthesis of natural products, functionally diverse molecules towards the discovery of novel biologically active compounds. [5] With people's increasing concerns about their living environment, the design of new MCRs with ecofriendliness, green procedures had drawn significant attention, especially in organic synthesis and drug discovery with environmentally benign solvents and reagents.…”

l-Proline and d-Proline (Chiral Amino Acid Catalysts)

“…2 Among the catalysts developed, L/D-proline and its derivatives catalyzed a wide range of reactions. 3 L/D-Proline collectively has the application as catalysts in asymmetric Mannich reactions for chiral β-aminocarbonyls, 4 aldehyde aldol reaction for the synthesis of erythrose equivalents, 5 domino Mannich-AzaMichael reactions, 6 Morita-Bayllis-Hillman reactions, 7 Heck cross-coupling reactions, 8 multicomponent reations, 9 in the synthesis of bioactive diketopiperazines, 10 spirooxindazoles 11 and also in phosphodiester bond linkages to recognize DNA and RNAs 12 and in bifunctional catalysts, it acts as co-catalyst. 13 In addition, the application in the preparation of a wide variety of chiral catalysts like chiral MOFs, 14 Barbas-List aldol catalysts, 15 bile acid catalysts 16 and has excellent use in autocatalysis strategy, to form the initial enantiorich isomers, which further autocatalyze the reactions.…”