Ultrasound-assisted three-component synthesis of 3-(5-amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones in water

Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

“…2) as the main product, in which the arylamine only provided the amino group to form the pyridyl ring [16–21]. There are only very few papers describing that either 2-naphthylamine [22–25], functionalized 5-aminopyrazoles [26–28], or 2-aminobenzothiazoles [29] reacted with isatin and cyclic 1,3-dicarbonyl compounds to give the similar spiro[dihydropyridine-oxindole] ( II , III in Fig. 2), in which both the amino group and the aryl ring were involved in the construction of the pyridyl ring.…”

A Metal-Free Approach for the Synthesis of 2-Tetralones via Carbanion-Induced Ring Transformation of 2H-Pyran-2-ones

“…attractive green technique, widely used as alternative energy source in many organic reactions. [27][28][29][30][31][32][33][34] Hence we carried out the same reaction of 2H-pyran-2-one 5a with spirocyclic ketone 6 under ultrasound irradiation at room temperature. Surprisingly, the reaction was complete in just 16 minutes and the ring-transformation product 7a was obtained in 84% yield (Table 2, entry 7).…”

Facile Multicomponent Mannich Reaction towards Biologically Active Compounds

“…The multi-component Mannich reaction includes reaction of cyclic iminium ions with enol compounds [22] which has been extended with annulated Nalkoxycarbonyl pyrrolinium ion with 2-trimethylsilyloxyfuran, coupling between optically active N-acylhydrazones with hydrazones, silyl enolates, [23] along with ketene silyl acetal, [24] as well as reaction between hydrazone ester with silicon enolates, combination of α-imino ester with aldehydes, and reaction of α-imino glyoxylate with α, α-difunctionalised aldehyde. [25] Moreover, α-imino ester with a glycine-containing Schiff base [26] with silyl enol ethers & N-acylimino ester or vinyl ethers, [27] the combination of acetate enolate together with α-amido sulfones or PMP-imines, [28] glyoxylate Schiff bases with ketene acetals, [29] silylketene acetals with alkynyl Schiff bases, [30] and hydroxyketone compounds and phosphonylimine [31] are also categorized under Mannich reaction. This review article describes the recent applications of multicomponent Mannich reaction for synthesising "antibiotics", "anti-inflammatory", "antimalarial", "antitumor" and "anticonvulsant" molecules.…”

“…The coupling of aldimines with silyl enol ether, [18] reaction of aldimine with fluorovinyl ether, [19] reaction of chiral aldimines with silyloxydienes, [20] along with reaction of fluorinated aldimines and aliphatic aldehydes [21] are some crucial variations. The multi‐component Mannich reaction includes reaction of cyclic iminium ions with enol compounds [22] which has been extended with annulated N ‐alkoxycarbonyl pyrrolinium ion with 2‐trimethylsilyloxyfuran, coupling between optically active N ‐acylhydrazones with hydrazones, silyl enolates, [23] along with ketene silyl acetal, [24] as well as reaction between hydrazone ester with silicon enolates, combination of α ‐imino ester with aldehydes, and reaction of α ‐imino glyoxylate with α , α ‐difunctionalised aldehyde [25] . Moreover, α ‐imino ester with a glycine‐containing Schiff base [26] with silyl enol ethers & N ‐acylimino ester or vinyl ethers, [27] the combination of acetate enolate together with α ‐amido sulfones or PMP‐imines, [28] glyoxylate Schiff bases with ketene acetals, [29] silylketene acetals with alkynyl Schiff bases, [30] and hydroxyketone compounds and phosphonylimine [31] are also categorized under Mannich reaction.…”