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Yicheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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FeCl3‐Catalyzed Condensation of 2‐Naphthol and Aldehydes under Solvent‐Free Reaction Conditions: An Efficient and Green Alternative for the Synthesis of 14‐Aryl(Alkyl)‐14‐H‐dibenzo[a, j]xanthenes
Chinese Journal of Chemistry, 2010Co-Authors: Bo Wang, Yicheng Zhang, Pinghua Li, Lei WangAbstract:An iron-catalyzed condensation of 2-naphthol with aldehydes has been described. In the presence of a catalytic amount of iron(III) chloride (5 mol%), the condensation Reaction of 2-naphthol and aldehydes underwent smoothly to generate the corresponding products in good to excellent yields under base-, acid-, ligand-, additive-, and Solvent-Free Reaction conditions.
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An Efficient and Practical Synthesis of Benzoxazoles from Acyl Chlorides and 2-Aminophenols Catalyzed by Lewis Acid In(OTf)3 under Solvent-Free Reaction Conditions†
Chinese Journal of Chemistry, 2010Co-Authors: Bo Wang, Yicheng Zhang, Pinhua Li, Lei WangAbstract:Benzoxazole derivatives have been prepared through the Reaction of substituted 2-aminophenols and acyl chlorides in the presence of catalytic amount of In(OTf)3 under Solvent-Free Reaction conditions in good to excellent yields. The method is simple, convenient, environmental-friendly, efficient and practical.
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sio2 nhc cu i an efficient and reusable catalyst for 3 2 cycloaddition of organic azides and terminal alkynes under Solvent Free Reaction conditions at room temperature
Tetrahedron, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng ZhangAbstract:Abstract A novel SiO2–NHC–Cu(I) 3b was developed and used as a highly efficient catalyst for [3+2] cycloaddition of organic azides and terminal alkynes. In the presence of SiO2–NHC–Cu(I) 3b (1 mol %), the Reactions of terminal alkynes with organic azides underwent smoothly to generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in excellent yields under Solvent-Free Reaction conditions at room temperature. Furthermore, catalyst 3b was quantitatively recovered from the Reaction mixture by a simple filtration and reused for 10 cycles without loss of its activity.
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SiO2–NHC–Cu(I): an efficient and reusable catalyst for [3+2] cycloaddition of organic azides and terminal alkynes under Solvent-Free Reaction conditions at room temperature
Tetrahedron, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng ZhangAbstract:Abstract A novel SiO2–NHC–Cu(I) 3b was developed and used as a highly efficient catalyst for [3+2] cycloaddition of organic azides and terminal alkynes. In the presence of SiO2–NHC–Cu(I) 3b (1 mol %), the Reactions of terminal alkynes with organic azides underwent smoothly to generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in excellent yields under Solvent-Free Reaction conditions at room temperature. Furthermore, catalyst 3b was quantitatively recovered from the Reaction mixture by a simple filtration and reused for 10 cycles without loss of its activity.
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highly efficient three component aldehyde alkyne amine coupling Reactions catalyzed by a reusable ps supported nhc ag i under Solvent Free Reaction conditions
Tetrahedron Letters, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng Zhang, Min WangAbstract:Abstract The development of a highly efficient, polystyrene-supported NHC – Ag(I) catalyst for the three-component coupling Reactions of aldehydes, alkynes, and amines (A 3 -coupling) was described. In the presence of PS – NHC – Ag(I) (2 mol %), the A 3 -Reactions were carried out at room temperature under Solvent-Free Reaction conditions and the corresponding propargylamines were generated in good to excellent yields. Furthermore, the catalyst could be reused at least 12 times without a significant loss of its catalytic activity.
Pinhua Li - One of the best experts on this subject based on the ideXlab platform.
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An Efficient and Practical Synthesis of Benzoxazoles from Acyl Chlorides and 2-Aminophenols Catalyzed by Lewis Acid In(OTf)3 under Solvent-Free Reaction Conditions†
Chinese Journal of Chemistry, 2010Co-Authors: Bo Wang, Yicheng Zhang, Pinhua Li, Lei WangAbstract:Benzoxazole derivatives have been prepared through the Reaction of substituted 2-aminophenols and acyl chlorides in the presence of catalytic amount of In(OTf)3 under Solvent-Free Reaction conditions in good to excellent yields. The method is simple, convenient, environmental-friendly, efficient and practical.
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sio2 nhc cu i an efficient and reusable catalyst for 3 2 cycloaddition of organic azides and terminal alkynes under Solvent Free Reaction conditions at room temperature
Tetrahedron, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng ZhangAbstract:Abstract A novel SiO2–NHC–Cu(I) 3b was developed and used as a highly efficient catalyst for [3+2] cycloaddition of organic azides and terminal alkynes. In the presence of SiO2–NHC–Cu(I) 3b (1 mol %), the Reactions of terminal alkynes with organic azides underwent smoothly to generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in excellent yields under Solvent-Free Reaction conditions at room temperature. Furthermore, catalyst 3b was quantitatively recovered from the Reaction mixture by a simple filtration and reused for 10 cycles without loss of its activity.
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SiO2–NHC–Cu(I): an efficient and reusable catalyst for [3+2] cycloaddition of organic azides and terminal alkynes under Solvent-Free Reaction conditions at room temperature
Tetrahedron, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng ZhangAbstract:Abstract A novel SiO2–NHC–Cu(I) 3b was developed and used as a highly efficient catalyst for [3+2] cycloaddition of organic azides and terminal alkynes. In the presence of SiO2–NHC–Cu(I) 3b (1 mol %), the Reactions of terminal alkynes with organic azides underwent smoothly to generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in excellent yields under Solvent-Free Reaction conditions at room temperature. Furthermore, catalyst 3b was quantitatively recovered from the Reaction mixture by a simple filtration and reused for 10 cycles without loss of its activity.
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highly efficient three component aldehyde alkyne amine coupling Reactions catalyzed by a reusable ps supported nhc ag i under Solvent Free Reaction conditions
Tetrahedron Letters, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng Zhang, Min WangAbstract:Abstract The development of a highly efficient, polystyrene-supported NHC – Ag(I) catalyst for the three-component coupling Reactions of aldehydes, alkynes, and amines (A 3 -coupling) was described. In the presence of PS – NHC – Ag(I) (2 mol %), the A 3 -Reactions were carried out at room temperature under Solvent-Free Reaction conditions and the corresponding propargylamines were generated in good to excellent yields. Furthermore, the catalyst could be reused at least 12 times without a significant loss of its catalytic activity.
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polymer immobilized pyrrolidine based chiral ionic liquids as recyclable organocatalysts for asymmetric michael additions to nitrostyrenes under Solvent Free Reaction conditions
European Journal of Organic Chemistry, 2008Co-Authors: Pinhua Li, Lei Wang, Min Wang, Yicheng ZhangAbstract:A polymer immobilized pyrrolidine-based chiral ionic liquid 5a was synthesized and was found to be a highly efficient catalyst for the Michael additions of ketones and aldehydes to nitrostyrenes, which afforded the corresponding adducts in good yields (up to 97 %), excellent enantioselectivities (up to >99 % ee) and high diastereoselectivities (up to >99:1 dr) under Solvent-Free Reaction conditions. In addition, the catalyst 5a could be reused at least eight times without a significant loss of its catalytic activity and stereoselectivity.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Stojan Stavber - One of the best experts on this subject based on the ideXlab platform.
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Lodination of Organic Compounds Using the Reagent System Ι2-30% aq. H2O2 under Organic Solvent-Free Reaction Conditions
Acta Chimica Slovenica, 2020Co-Authors: Jasminka Pavlinac, Marko Zupan, Stojan StavberAbstract:Lodine was efficiently introduced into the methoxy substituted aromatic compounds, acetophenone, 1-indanone and 1-tetralone using the elemental iodine / 30% aq. H 2 O 2 system under organic Solvent-Free Reaction conditions (SFRC) and two types of iodo-functionalisation through an electrophilic process were observed. Iodination of the aromatic ring in the case of dimethoxy- and trimethoxy benzenes took place, while aryl alkyl ketones were regioselectively iodinated at the alkyl position next to a carbonyl group. Based on the ratio of substrate : I 2 : H 2 O 2 required for the most efficient iodo-transformation, two different roles of H 2 O 2 in the Reaction route can be distinguished. Different forms of H 2 O 2 as mediators of iodination, namely 30% aq. H 2 O 2 and two solid forms urea-H 2 O 2 and sodium percarbonate (2Na 2 CO 3 . 3H 2 O 2 ), were comparatively evaluated in terms of efficiency under SFRC. Reactions using 30% aq. H 2 O 2 as the mediator of iodination under SFRC were compared with those performed in water as Reaction medium.
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direct halogenation of alcohols with halosilanes under catalyst and organic Solvent Free Reaction conditions
Tetrahedron Letters, 2016Co-Authors: Njomza Ajvazi, Stojan StavberAbstract:Abstract A chemoselective method for the direct halogenation of different types of alcohols with halosilanes under catalyst- and Solvent-Free Reaction conditions (SFRC) is reported. Various primary, secondary and tertiary benzyl alcohols and tertiary alkyl alcohols were directly transformed to the corresponding benzyl and alkyl halides, respectively, using chlorotrimethylsilane (TMSCl) and bromotrimethylsilane (TMSBr).
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Towards Greener Fluorine Organic Chemistry: Direct Electrophilic Fluorination of Carbonyl Compounds in Water and Under Solvent-Free Reaction Conditions
Advanced Synthesis & Catalysis, 2010Co-Authors: Gaj Stavber, Stojan StavberAbstract:Selective and efficient fluorination of organic 1,3-dicarbonyl compounds was achieved using the electrophilic fluorinating reagents Selectfluor ™ F-TEDA-BF 4 (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis-tetrafluoroborate) in aqueous medium or Accufluor ™ NFSi (N-fluorobenzene-sulfonimide) under Solvent-Free Reaction conditions (SFRC). Under both Reaction conditions cyclic 1,3-dicarbonyl compounds were transformed into 2-fluoro-substituted derivatives and acyclic analogues into 2,2-difluoro-substituted compounds, while the Reactions of 1-trifluoromethyl-substituted 1,3-dicarbonyls in water resulted in the formation of 2,2-difluoro-3,3-dihydroxy-1-one derivatives. The reactivity of the starting material in water was found to be dependent on its enolizability, hydrophobic interactions and aggregate state at the Reaction temperature. Reactions under SFRC proceeded in the molten eutectic phase of the reactants. The technique of competitive reactivity was used in order to evaluate and better understand the effects of Reaction conditions on the course of these Reactions.
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visible light promoted wohl ziegler functionalization of organic molecules with n bromosuccinimide under Solvent Free Reaction conditions
Helvetica Chimica Acta, 2009Co-Authors: Marjan Jereb, Marko Zupan, Stojan StavberAbstract:The visible-light-induced transformation of toluenes with N-bromosuccinimide (NBS) under Solvent-Free Reaction conditions (SFRC) was studied. The Reaction took place in spite of the very restricted molecular motion; toluenes could be regioselectively converted to benzyl bromides. Selective radical-chain Reactions with NBS were carried out in liquid/liquid and in solid/solid systems; furthermore, Reactions could be performed in the presence of air. The radical scavenger TEMPO (=2,2,6,6-tetramethylpiperidin-1-yloxy) completely suppressed the side-chain bromination of toluenes with NBS under SFRC. Electron-withdrawing groups decreased the reactivity of the toluenes, and the Hammett Reaction constant ρ+=−1.7 indicated involvement of polar radical intermediates with electrophilic character.
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Visible‐Light‐Promoted Wohl–Ziegler Functionalization of Organic Molecules with N‐Bromosuccinimide under Solvent‐Free Reaction Conditions
Helvetica Chimica Acta, 2009Co-Authors: Marjan Jereb, Marko Zupan, Stojan StavberAbstract:The visible-light-induced transformation of toluenes with N-bromosuccinimide (NBS) under Solvent-Free Reaction conditions (SFRC) was studied. The Reaction took place in spite of the very restricted molecular motion; toluenes could be regioselectively converted to benzyl bromides. Selective radical-chain Reactions with NBS were carried out in liquid/liquid and in solid/solid systems; furthermore, Reactions could be performed in the presence of air. The radical scavenger TEMPO (=2,2,6,6-tetramethylpiperidin-1-yloxy) completely suppressed the side-chain bromination of toluenes with NBS under SFRC. Electron-withdrawing groups decreased the reactivity of the toluenes, and the Hammett Reaction constant ρ+=−1.7 indicated involvement of polar radical intermediates with electrophilic character.
Lei Wang - One of the best experts on this subject based on the ideXlab platform.
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In(OTf)3‐Catalyzed Synthesis of Functionalized 1,5‐Benzodiazepines from o‐Phenylenediamine and Alkyl Propiolates under Solvent‐Free Reaction Conditions
Chinese Journal of Chemistry, 2011Co-Authors: Haisheng Wu, Jin Yang, Lei WangAbstract:A simple, environmental-friendly, and practical method for the synthesis of benzodiazepine derivatives through a Reaction of substituted o-phenylenediamines with alkyl propiolates has been developed. The Reactions generated the 1,5-benzodiazepines in good to excellent yields in the presence of catalytic amount of In(OTf)3 under Solvent-Free Reaction conditions.
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FeCl3‐Catalyzed Condensation of 2‐Naphthol and Aldehydes under Solvent‐Free Reaction Conditions: An Efficient and Green Alternative for the Synthesis of 14‐Aryl(Alkyl)‐14‐H‐dibenzo[a, j]xanthenes
Chinese Journal of Chemistry, 2010Co-Authors: Bo Wang, Yicheng Zhang, Pinghua Li, Lei WangAbstract:An iron-catalyzed condensation of 2-naphthol with aldehydes has been described. In the presence of a catalytic amount of iron(III) chloride (5 mol%), the condensation Reaction of 2-naphthol and aldehydes underwent smoothly to generate the corresponding products in good to excellent yields under base-, acid-, ligand-, additive-, and Solvent-Free Reaction conditions.
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An Efficient and Practical Synthesis of Benzoxazoles from Acyl Chlorides and 2-Aminophenols Catalyzed by Lewis Acid In(OTf)3 under Solvent-Free Reaction Conditions†
Chinese Journal of Chemistry, 2010Co-Authors: Bo Wang, Yicheng Zhang, Pinhua Li, Lei WangAbstract:Benzoxazole derivatives have been prepared through the Reaction of substituted 2-aminophenols and acyl chlorides in the presence of catalytic amount of In(OTf)3 under Solvent-Free Reaction conditions in good to excellent yields. The method is simple, convenient, environmental-friendly, efficient and practical.
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sio2 nhc cu i an efficient and reusable catalyst for 3 2 cycloaddition of organic azides and terminal alkynes under Solvent Free Reaction conditions at room temperature
Tetrahedron, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng ZhangAbstract:Abstract A novel SiO2–NHC–Cu(I) 3b was developed and used as a highly efficient catalyst for [3+2] cycloaddition of organic azides and terminal alkynes. In the presence of SiO2–NHC–Cu(I) 3b (1 mol %), the Reactions of terminal alkynes with organic azides underwent smoothly to generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in excellent yields under Solvent-Free Reaction conditions at room temperature. Furthermore, catalyst 3b was quantitatively recovered from the Reaction mixture by a simple filtration and reused for 10 cycles without loss of its activity.
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SiO2–NHC–Cu(I): an efficient and reusable catalyst for [3+2] cycloaddition of organic azides and terminal alkynes under Solvent-Free Reaction conditions at room temperature
Tetrahedron, 2008Co-Authors: Pinhua Li, Lei Wang, Yicheng ZhangAbstract:Abstract A novel SiO2–NHC–Cu(I) 3b was developed and used as a highly efficient catalyst for [3+2] cycloaddition of organic azides and terminal alkynes. In the presence of SiO2–NHC–Cu(I) 3b (1 mol %), the Reactions of terminal alkynes with organic azides underwent smoothly to generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in excellent yields under Solvent-Free Reaction conditions at room temperature. Furthermore, catalyst 3b was quantitatively recovered from the Reaction mixture by a simple filtration and reused for 10 cycles without loss of its activity.
Marjan Jereb - One of the best experts on this subject based on the ideXlab platform.
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Chemistry of Organo Halogenic Molecules. Part 229. The Role of Iodine in Acetyl Group Transfer to Oxygen-containing Molecules under Solvent-Free Reaction Conditions
Acta Chimica Slovenica, 2020Co-Authors: Marjan Jereb, Dejan Vrazic, Marko ZupanAbstract:Iodine was shown to be an efficient catalyst for the conversion of phenyl-substituted aldehydes to the corresponding 1,1-diacetate derivatives under Solvent-Free Reaction conditions (SFRC), which are superior to the classical solution conditions. It was demonstrated that the order of the addition of reactants was of fundamental importance; the ability of substituents on the phenyl ring modified reactivity irrespectively to electronic properties, the pentafluorophenyl group significantly reduced reactivity of the aldehyde. Alcohols yielded acetates; acetic anhydride was found to be the most ef- ficient reagent; isopropenyl acetate and vinyl acetate were less reactive; however the pentafluorophenyl group enhanced reactivity with the latter two reagents. Beside the esterification of benzyl alcohol and its pentafluorophenyl analogue, the formation of acetals was also observed.
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iodine catalyzed disproportionation of aryl substituted ethers under Solvent Free Reaction conditions
Organic and Biomolecular Chemistry, 2013Co-Authors: Marjan Jereb, Dejan VrazicAbstract:Iodine was demonstrated to be an efficient catalyst for disproportionation of aryl-substituted ethers under Solvent-Free Reaction conditions. Variously substituted 1,1,1′,1′-tetraaryldimethyl ethers were transformed into the corresponding diarylketone and diarylmethane derivatives. I2-catalyzed transformation of 4-methoxyphenyl substituted ethers yielded mono- and dialkylated Friedel–Crafts products as well. Treatment of trityl alkyl and trityl benzyl ethers with a catalytic amount of iodine produced triphenylmethane and the corresponding aldehydes and ketones. The electron-donating substituents facilitated the Reaction, while the electron-withdrawing groups retarded it; the difference in reactivity is not very high. Such an observation may be in favour of hydride transfer, predominantly from the less electron rich side of the ether with more stable carbocation formation. With the isotopic studies it was established that a substantial portion of the C–H bond scission took place in the rate-determining step, while the carbonyl oxygen atom originated from the starting ether, and not from the air. The transformation took place under air and under argon, and HI was not a functioning catalyst.
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Highly atom economical uncatalysed and I2-catalysed silylation of phenols, alcohols and carbohydrates, using HMDS under Solvent-Free Reaction conditions (SFRC)
Tetrahedron, 2012Co-Authors: Marjan JerebAbstract:Abstract An uncatalysed silylation of phenols, regardless on the aggregate state and nature of the substituents with 0.55 equiv of HMDS under Solvent-Free Reaction conditions (SFRC) at room temperature is reported. Sterically hindered phenols, carbohydrates and most of the alcohols additionally required a catalytic amount (up to 2 mol %) of iodine. The Reaction protocol is very simple; obtaining a pure product, particularly of uncatalysed Reactions, was frequently a completely Solvent-Free process.
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Dual behavior of alcohols in iodine-catalyzed esterification under Solvent-Free Reaction conditions
Tetrahedron Letters, 2009Co-Authors: Marjan Jereb, Dejan Vrazic, Marko ZupanAbstract:Abstract The dual behavior phenomenon of alcohols in iodine-catalyzed esterification under Solvent-Free Reaction conditions (SFRCs) is described; the governing factor is the stability of the carbonium ion generated from the alcohol; high concentration Reaction conditions (HCRCs) or dilute solutions are much less suitable. In the case of benzylic alcohols, loss of optical activity was noted, whereas alkyl alcohols furnished a product with retention of stereochemistry.
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visible light promoted wohl ziegler functionalization of organic molecules with n bromosuccinimide under Solvent Free Reaction conditions
Helvetica Chimica Acta, 2009Co-Authors: Marjan Jereb, Marko Zupan, Stojan StavberAbstract:The visible-light-induced transformation of toluenes with N-bromosuccinimide (NBS) under Solvent-Free Reaction conditions (SFRC) was studied. The Reaction took place in spite of the very restricted molecular motion; toluenes could be regioselectively converted to benzyl bromides. Selective radical-chain Reactions with NBS were carried out in liquid/liquid and in solid/solid systems; furthermore, Reactions could be performed in the presence of air. The radical scavenger TEMPO (=2,2,6,6-tetramethylpiperidin-1-yloxy) completely suppressed the side-chain bromination of toluenes with NBS under SFRC. Electron-withdrawing groups decreased the reactivity of the toluenes, and the Hammett Reaction constant ρ+=−1.7 indicated involvement of polar radical intermediates with electrophilic character.