Benzyltriphenylphosphonium tribromide（BTPTB） has been applied as an efficient catalyst for the preparation of bis（indolyl）-methanes （BIMs） via electrophilic substitution of indoles with aldehydes in the absence ...Benzyltriphenylphosphonium tribromide（BTPTB） has been applied as an efficient catalyst for the preparation of bis（indolyl）-methanes （BIMs） via electrophilic substitution of indoles with aldehydes in the absence of solvent.展开更多
In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Sim...In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.展开更多
Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid, ortho esters and amines leading to the formation of 4（3H）-quinazolinone derivatives in good yields at ...Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid, ortho esters and amines leading to the formation of 4（3H）-quinazolinone derivatives in good yields at room temperature under solvent-free conditions.展开更多
Pentafluorophenylammonium triflate（PFPAT） was found to be a highly efficient catalyst for the preparation of 2,4,6- triarylpyridines from the reaction of acetophenone derivatives,aromatic aldehydes and ammonium acet...Pentafluorophenylammonium triflate（PFPAT） was found to be a highly efficient catalyst for the preparation of 2,4,6- triarylpyridines from the reaction of acetophenone derivatives,aromatic aldehydes and ammonium acetate.Present methodology offers several advantages,such as short reaction time,high yields,simple procedure with an easy work-up and the absence of any volatile and hazardous organic solvent.In addition,this catalytic system can act as an active,inexpensive,metal-free,recoverable and recyclable catalyst.展开更多
Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes unde...Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.展开更多
A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V（HSO4）3 in solution and under solvent free conditions. Mild reaction conditions, high yiel...A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V（HSO4）3 in solution and under solvent free conditions. Mild reaction conditions, high yields of the products, easy procedure and selective acetylation of alcohols and phenols in the presence of amines and thiols are the main advantages of this procedure.展开更多
A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of ali...A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH;/silica chloride at room temperature,afforded excellent yield of the corresponding amines.展开更多
V（HSO4）3 has been found to be an efficient reagent for the promotion of the oxidation of alcohols and trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds with Cu（NO3...V（HSO4）3 has been found to be an efficient reagent for the promotion of the oxidation of alcohols and trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds with Cu（NO3）2-3H2O in the absence of solvent.展开更多
1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in re...1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to high yields.展开更多
A simple and fastthree-component synthesis of new and biologically active hexahydro-2-quinolinecarboxylic acid scaf-fold 4 was carried out using cyclocondensation reaction of arylmethylidenepyruvic acids 1, 1,3-cycloh...A simple and fastthree-component synthesis of new and biologically active hexahydro-2-quinolinecarboxylic acid scaf-fold 4 was carried out using cyclocondensation reaction of arylmethylidenepyruvic acids 1, 1,3-cyclohexandiones 2 and ammonium acetate 3 under solvent-free conditions and at room temperature. This protocol has the advantages of facility, easy work-up, high yields, short reaction time and environmentally friendly character.展开更多
An efficient and simple procedure for the synthesis of novel isatin derivatives is described. Michael addition of aniline Schiff bases of isatin or p-toluidine Schiff bases of isatin to fumaric esters affords the Mich...An efficient and simple procedure for the synthesis of novel isatin derivatives is described. Michael addition of aniline Schiff bases of isatin or p-toluidine Schiff bases of isatin to fumaric esters affords the Michael adduct com- pounds in good to high yields in the presence of K2CO3 and tetrabutylammonium bromide （TBAB） under sol- vent-free conditions. Repeating of this reaction about spiro[l,3-dioxolane-2,3＇-indol]-2＇（l＇H）-one, as a Michael do- nor, in the presence of 1,4-diazabicyclo[2.2.2]octane （DABCO） gives Michael adducts in remarkable yields under the same conditions.展开更多
This paper describes a very simple, efficient synthesis of quinazolinones and chromeno[d]pyrimidinones from the reaction of aryl aldehydes, urea/thiourea and active methylene compounds（dimedone/4-hydroxycoumarin） us...This paper describes a very simple, efficient synthesis of quinazolinones and chromeno[d]pyrimidinones from the reaction of aryl aldehydes, urea/thiourea and active methylene compounds（dimedone/4-hydroxycoumarin） using nano-sized CuI particles under solvent-free conditions. The highlights of this new method are based on using an effective and recyclable catalyst, affording high yields of products,mild reaction conditions, facile work-up and purification.展开更多
A new polymeric reagent, cross-linked poly（4-vinylpyridine） supported azide ion, [P4-VP]N3, was introduced as polymeric reagents for efficient and regioselective conversion of epoxides to azidohydrins in the presenc...A new polymeric reagent, cross-linked poly（4-vinylpyridine） supported azide ion, [P4-VP]N3, was introduced as polymeric reagents for efficient and regioselective conversion of epoxides to azidohydrins in the presence of cross-linked poly（4-vinylpyridine） supported sulfuric acid, [P4-VP]H2SO4, as a solid proton source and as catalyst under solvent-free conditions. The advantages of this polymeric reagent over some of those reported in the literature are easy work-up procedure and regeneration of the reagent.展开更多
A mild and efficient method for the oxidative deprotection of 1,3-oxathiolanes with Fe（NO3）3·9H2O and Cu（NO3）2·3H2O in the absence of solvent is reported.
A Yb（OTf）3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved, which could afford the desired products with yields ranged from moderate to excellent.
文摘Benzyltriphenylphosphonium tribromide（BTPTB） has been applied as an efficient catalyst for the preparation of bis（indolyl）-methanes （BIMs） via electrophilic substitution of indoles with aldehydes in the absence of solvent.
基金the University of Guilan Research Council for the partial support
文摘In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.
文摘Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid, ortho esters and amines leading to the formation of 4（3H）-quinazolinone derivatives in good yields at room temperature under solvent-free conditions.
基金supported by the Islamic Azad University,Tonekabon Branch
文摘Pentafluorophenylammonium triflate（PFPAT） was found to be a highly efficient catalyst for the preparation of 2,4,6- triarylpyridines from the reaction of acetophenone derivatives,aromatic aldehydes and ammonium acetate.Present methodology offers several advantages,such as short reaction time,high yields,simple procedure with an easy work-up and the absence of any volatile and hazardous organic solvent.In addition,this catalytic system can act as an active,inexpensive,metal-free,recoverable and recyclable catalyst.
基金financial support received from Council of Scientific and Industrial Research(No.02(0025)/ 11/EMR-Ⅱ),New Delhi
文摘Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.
基金this work by the research affair,University of Guilan,Rasht,Iran,
文摘A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V（HSO4）3 in solution and under solvent free conditions. Mild reaction conditions, high yields of the products, easy procedure and selective acetylation of alcohols and phenols in the presence of amines and thiols are the main advantages of this procedure.
基金support of this work from the Research Council of Mazandaran University gratefully acknowledged.
文摘A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH;/silica chloride at room temperature,afforded excellent yield of the corresponding amines.
基金the University of Guilan Research Council for the partial support of this work
文摘V（HSO4）3 has been found to be an efficient reagent for the promotion of the oxidation of alcohols and trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds with Cu（NO3）2-3H2O in the absence of solvent.
基金the University of Guilan Research Council for the partial support
文摘1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to high yields.
文摘A simple and fastthree-component synthesis of new and biologically active hexahydro-2-quinolinecarboxylic acid scaf-fold 4 was carried out using cyclocondensation reaction of arylmethylidenepyruvic acids 1, 1,3-cyclohexandiones 2 and ammonium acetate 3 under solvent-free conditions and at room temperature. This protocol has the advantages of facility, easy work-up, high yields, short reaction time and environmentally friendly character.
文摘An efficient and simple procedure for the synthesis of novel isatin derivatives is described. Michael addition of aniline Schiff bases of isatin or p-toluidine Schiff bases of isatin to fumaric esters affords the Michael adduct com- pounds in good to high yields in the presence of K2CO3 and tetrabutylammonium bromide （TBAB） under sol- vent-free conditions. Repeating of this reaction about spiro[l,3-dioxolane-2,3＇-indol]-2＇（l＇H）-one, as a Michael do- nor, in the presence of 1,4-diazabicyclo[2.2.2]octane （DABCO） gives Michael adducts in remarkable yields under the same conditions.
基金the financial support from the Research Council of East Tehran Branch, Islamic Azad University
文摘This paper describes a very simple, efficient synthesis of quinazolinones and chromeno[d]pyrimidinones from the reaction of aryl aldehydes, urea/thiourea and active methylene compounds（dimedone/4-hydroxycoumarin） using nano-sized CuI particles under solvent-free conditions. The highlights of this new method are based on using an effective and recyclable catalyst, affording high yields of products,mild reaction conditions, facile work-up and purification.
文摘A new polymeric reagent, cross-linked poly（4-vinylpyridine） supported azide ion, [P4-VP]N3, was introduced as polymeric reagents for efficient and regioselective conversion of epoxides to azidohydrins in the presence of cross-linked poly（4-vinylpyridine） supported sulfuric acid, [P4-VP]H2SO4, as a solid proton source and as catalyst under solvent-free conditions. The advantages of this polymeric reagent over some of those reported in the literature are easy work-up procedure and regeneration of the reagent.
文摘A mild and efficient method for the oxidative deprotection of 1,3-oxathiolanes with Fe（NO3）3·9H2O and Cu（NO3）2·3H2O in the absence of solvent is reported.
基金the National Key Technology R&D Program(No.2007BAI34B00)the National Natural Science Foundation of China(No.20876147 and 20676123)the Natural Science Foundation of Zhejiang Province(No.Y4080107) for financial support.
文摘A Yb（OTf）3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved, which could afford the desired products with yields ranged from moderate to excellent.
