Base catalyzed multicomponent synthesis of spiroheterocycles with fused heterosystems

Abstract

Structurally diverse spiroheterocycles incorporating medicinally privileged heterosystems have been synthesized by a simple and convenient synthesis involving triethylamine catalyzed multicomponent domino reaction of 2-aminobenzothiazoles with isatin and cyclic 1,3-diketones.

Sulfanilic acid functionalized mesoporous SBA-15: A water-tolerant solid acid catalyst for the synthesis of uracil fused spirooxindoles as antioxidant agents

“…20 Owing to their pharmaceutical importance, various synthetic methods for producing spirocyclic oxindoles have been reported. [21][22][23][24][25][26][27][28][29][30][31] Despite the efficiency of the reported protocols, some of them suffer from drawbacks such as long reaction time, harsh reaction conditions, corrosiveness, toxicity, cost, as well as unreusability of catalyst.…”

An Efficient and Facile Multicomponent Reaction for the Synthesis of 5′,6′‐dihydro‐6′‐hydroxy‐6′‐(trifluoromethyl)‐1′H‐spiro[indoline‐3,4′‐pyrimidine]‐2,2′(3′H)‐dione Derivatives under Solvent‐Free Conditions

“…Isatins were often used for preparation of many spiro‐heterocyclic compounds with different carbonyl compounds . Under investigation, it could be found that many β‐dicarbonyl compounds such as cyclic α‐cyanoacetic ester , barbituric acid , dimedone , 4‐hydroxycoumarin , dimethyl acetylenedicarboxylate , 2‐hydroxy‐1,4‐naphthoquinone , and 3‐methyl‐2‐pyrazolin‐5‐one were applied to this synthesis. In order to design and prepare new spiro‐heterocyclic compounds, in this research, we want to use some novel carbonyl compounds to react with isatins and urea to give fresh spiro‐heterocyclic compounds.…”

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.…”

“…Although at present the exact mechanism of this three-component reaction is not very clear, a plausible reaction mechanism for the formation of spiro[dihydropyridine-oxindoles] is presented based on the similar multicomponent reactions of isatins [22–29]. Firstly, the reaction of isatin with one equivalent of cyclopentane-1,3-dione in acetic acid forms an aldol adduct ( A in Scheme 3).…”