ChemInform Abstract: Carbon—SO₃H: A Novel and Recyclable Solid Acid Catalyst for the Synthesis of Spiro[4H‐pyran‐3,3′‐oxindoles].

Abstract

Spiro[4H-pyran-3,3'-oxindoles]. -The title catalyst, derived from bioglycerol, is successfully used for the one-pot three-component condensation of isatins or acenaphthenequinone with 1,3-dicarbonyl compounds and malononitrile or ethyl cinnnamate. -(RAO, B. M.; REDDY, G. N.; REDDY, T. V.; DEVI, B. L. A. P.; PRASAD, R. B. N.; YADAV, J. S.; REDDY*, B. V. S.; Tetrahedron Lett. 54 (2013) 20, 2466-2471, http://dx.

The preparation of polyvinyl imidazole-functionalized magnetic biochar decorated by silver nanoparticles as an efficient catalyst for the synthesis of spiro-2-Amino-4H-pyran compounds

“…The catalytic strength of our specific catalyst (biochar/Fe 3 O 4 /PVIm/Ag) is compared with the recently detailed MCRs including acenaphthoquinone, malononitrile, and dimethyl ketone to use 2′-amino-tetrahydro-2 H -spiro[acenaphthylen-1,4′-chromeno]-3′-carbonitrile ( 14a ) and different catalysts, such as CaCl 2 57 , Fe 3 O 4 @Cs-CsO 3 H 56 , Na 2 EDTA 58 , HAuCl 4 . 3H 2 O 59 , Meglumine 41 , Fe 2 O 3 60 , HEAA 61 , Cu(OAc) 2 .H 2 O 46 , Fe 3 O 4 @CS-SO 3 H NPs 62 , Amb-400Cl (IRA-400 Cl) 63 , C 4 (DABCO-SO 3 H) 2 .4Cl 64 , Carbon-SO 3 H 65 , 1-butyl-3-methylimidazolium hydroxide ([bmim][OH] 66 , DBU 67 , (SB-DBU)Cl 68 , PEG-Ni nanoparticles 69 , trisodium citrate dihydrate 70 , PC/AgNPs 35 and new catalyst biochar/Fe 3 O 4 /PVIm/Ag. It seems that our new catalyst is better than other catalysts in more items.…”

A Sulfonic Acid Polyvinyl Pyridinium Ionic Liquid Catalyzes the Multi-Component Synthesis of Spiro-indoline-3,5′-pyrano[2,3-d]-pyrimidines and -Pyrazines

“…Syntheses comparable to ours required reaction times from 4 to 12 h at ambient temperature and 18 W while light LEDs [13]. Highly efficient recoverable catalysts have been developed [4,7,19,20,[35][36][37][38], including SO 3 H functionalized nanomaterials and polymers [4,7,19,20,35,36], 1-(2-aminoethyl)piperazine modified graphene oxide material [11], and L-proline-melamine polymers [38]. They are generally easier to separate than homogeneous catalysts.…”

“…Recently, spiro-indoline-3,4 -pyrano [2,3-c]pyrazoles were also tested as corrosion inhibitors [14]. One option for the synthesis of spiroindoline-3,4 -pyranes is the three-component reaction of 1-alkylindoline-2,3-diones with malonitrile derivatives and an activated enolate (Scheme 1B) [2,[4][5][6]8,[11][12][13][15][16][17][18][19][20][21][22]. Using such procedures, reactions of N-alkyl-1-(methylthio)-2-nitroethenamines, barbituric acid, and isatin (1H-indole-2,3-dione) in water produced spiroindoline-3,4 -pyrano [2,3-c]pyrimidines [15], the three-component reaction of barbituric acids, isatin, and cyclohexane-1,3-diones catalyzed by para-toluene sulfonic-acidproduced spiro[chromeno [2,3-d]pyrimidine-5,3-indoline]-tetraones [16], and spiroindoline-3,4 -pyrano [2,3-c]naphthalenes were obtained from isatin or its N-methyl derivative and 1or 2-naphthol in reactions catalyzed by InCl 3 under microwave conditions [21].…”

“…Our idea of using an acidic polymer catalyst based on poly(4-vinyl pyridine) was motivated by the wish to find a heterogenized (supported) and thus easily removable acidic catalyst for the versatile reactions shown in Scheme 2. Similar approaches using "Carbon-SO3H" [20], "silica-sulfuric acid nanoparticles" [19], magnetically removable Fe3O4@SiO2-SO3H and Fe3O4@SiO2[(CH2)3-DABCO-SO3H]Cl2 nanocatalysts [7], H2SO4-functionalized graphitic carbon nitride [35], and sulfonated nanoporous silica (SBA-15-Pr-SO3H) [36] for the synthesis of spirooxindole pyranes were previously reported. We have recently used a sim- Polymers with acidic protons in their structures and ionic liquid-polymer composites have found applications in fuel cells, in biomedical applications, and as catalysts [30][31][32][33][34] and different methods such as grafting, crosslinking, and functionalization procedures have been developed to produce such materials.…”

“…Our idea of using an acidic polymer catalyst based on poly(4-vinyl pyridine) was motivated by the wish to find a heterogenized (supported) and thus easily removable acidic catalyst for the versatile reactions shown in Scheme 2. Similar approaches using "Carbon-SO 3 H" [20], "silica-sulfuric acid nanoparticles" [19], magnetically removable Fe 3 O 4 @SiO 2 -SO 3 H and Fe 3 O 4 @SiO 2 [(CH 2 ) 3 -DABCO-SO 3 H]Cl 2 nanocatalysts [7], H 2 SO 4 -functionalized graphitic carbon nitride [35], and sulfonated nanoporous silica (SBA-15-Pr-SO 3 H) [36] for the synthesis of spirooxindole pyranes were previously reported. We have recently used a similar solid acid catalyst, di(3-propylsulfonic acid grafted on NiFe 2 O 4 @SiO 2 for the synthesis of chromeno [4,3d]pyrido [1,2-a]pyrimidine derivatives [26].…”