A clean and expedient synthesis of spirooxindoles catalyzed by silica–sulfuric acid nanoparticles as an efficient and reusable reagent

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

“…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].…”

Preparation and characterization of BF3 supported on coconut shell as a novel and effective nano-catalyst for one-pot synthesis of pyrano[2,3-d]pyrimidines

“…Recently, nano-solid-supported reagents such as nanocrystalline TiO 2 -HClO 4 [17], nano-TiCl 4 •SiO 2 [18], nano-SnCl 4 •SiO 2 [19], nano-sawdust-BF 3 [20], nano-sawdust-OSO 3 H [21], BF 3 -SiO 2 nano-particles [22], HClO 4 -SiO 2 nano-particles [23], nano-cellulose-OSO 3 H [24], nano-silica sulfuric acid [25], SbCl 5 /SiO 2 nano-particles [26], Pt@GO-PVP nano-composite [27], RhPt/TC@GO NPs [28], graphene oxide [29], and monodisperse Pt NPs@AC [30] have developed due to the high activity and selectivity [31].…”

“…During the course of our studies and investigations on the synthesis of pyrano[2,3-d]pyrimidine compounds and our interest in MCRs [20][21][22][23][24][25], we intended to study the feasibility of synthesizing their derivatives by the one-pot threecomponent condensation reactions strategy of aromatic aldehydes (1a-j) with ethyl cyanoacetate or malononitrile 2 and barbituric acid 3 in the presence of boron trifluoride supported on coconut shell (nano-BF 2 O-coc) as a novel nanocatalyst at reflux ethanol (Scheme 1).…”

Nano-sawdust–BF3 as a new, cheap, and effective nano catalyst for one-pot synthesis of 2-amino benzo[h]chromene derivatives

“…In recent years, there has been growing interest in finding inexpensive and effective solid acid nano catalyst such as nanocrystalline TiO 2 -HClO 4 [7], nano-TiCl 4 ÁSiO 2 [8][9][10] nano-SnCl 4 ÁSiO 2 [11,12] nano-BF 3 ÁSiO 2 [13][14][15] HClO 4 -SiO 2 nanoparticles [16] and nano-silica sulfuric acid [17][18][19][20][21][22][23]. Sawdust is one of the most common materials that used for various chemical industries such as removing pollutants from water [24], the color removal from textile industry [25], the removing cationic, anionic, and disperse dyes from aqueous solution [26] and the CuFe 2 O 4 /sawdust composite was used for removal of cyanine acid blue from aqueous solution [27].…”

“…Therefore, the development of a simple, mild, and efficient method is still needed. In continuation of our previous research on the use of solid nano catalyst in organic synthesis [14][15][16][17][18][19][20][21], the nano-sawdust-BF 3 as a new catalyst has been applied for the synthesis of 2-amino benzo[h]chromene derivatives.…”