- Dual-parameter correlations on rate of dehydration step of a condensation reaction in aqueous solutions of ethanol, propan-2-ol and 2-methylpropan-2-ol
-
The reaction kinetics of the dehydration step of the condensation reaction between phenylhydrazine and benzaldehyde was studied spectrophotometrically in aqueous solutions of ethanol, propan-2-ol and 2-methylpropan-2-ol at pH 11.5 at 25 °C. The apparent second-order rate constants k2app of the reaction increase with mole fraction of water in all the aqueous solutions. Single-parameter correlations of log k2app versus π* (dipolarity/polarizability), α (hydrogen-bond donor acidity) and ETN (normalized polarity parameter) were obtained in all the aqueous solutions. In all cases, the correlations versus ETN and π* are acceptable, but correlations versus α are poor (e.g. in aqueous solutions of ethanol the correlation coefficients are 0.964, 0.967, and 0.751 respectively). The results of dual-parameter correlations of log k2app versus π* and α in all cases represent improvements with regard to the single-parameter models (in aqueous solutions of ethanol r = 0.995; s.e. = 0.038; n = 13). The apparent second-order rate constants of the reaction increase with α, π* and ETN. Increasing the hydrogen-bond donor acidity of the solvent stabilizes the activated complex of the reaction via hydrogen-bond formation with the intermediate. A dual-parameter equation of log k2app versus π* and α was obtained for the combined data set of aqueous solutions (n = 35, r = 0.989, s.e. = 0.062, F2.32 = 719.21), in which π* has the major effect on the reaction rate relative to α. Copyright
- Habibi Yangjeh,Gholami,Mostaghim
-
-
Read Online
- METHODS OF FORMING IMINES, IMINE-RELATED AND IMINE-DERIVED COMPOUNDS USING GREEN SOLVENTS
-
The present disclosure relates to using green solvents to synthesize an array of imines, imine-related and imine-derived compounds in an efficient and eco-friendly matter, satisfying green chemistry requirements. Reaction embodiments are performed using solvents, such as ethyl lactate and dimethyl isosorbide, which are both individually characterized as green. In embodiments, solvents include lactic whey and/or water as co-solvents. In these green solvents, the synthesis process discussed herein can produce up to quantitative yields of product at room temperature in a short duration. Embodiments include a method of forming an imine, imine-related or imine-derived compound product. In embodiments, the methods include mixing an aldehyde reactant with a nucleophilic/nitrogen-containing reactant in a green solvent at a temperature between negative twenty degrees Celsius (?20° C.) and positive fifty degrees Celsius (50° C.); stirring the mixture; and forming an imine, imine-related or imine-derived compound product.
- -
-
Paragraph 0186-0189
(2021/10/22)
-
- 1, 3-diaryl-1, 2, 4-triazole compound as well as preparation method and application thereof
-
The invention discloses a 1, 3-diaryl-1, 2, 4-triazole compound, which has a novel structure shown in a structural general formula I and has better selective inhibition activity on HDAC6. The invention also discloses a preparation method of the compound, aryl groups and 4-amino-N-hydroxy-benzamide groups are introduced to a 1, 2, 4-triazole matrix for modification, a series of compounds with novelstructures are synthesized, and the method has the advantages of mild reaction conditions, simple operation, high yield and the like. The invention also discloses an application of the compound in preparation of a medicine for selectively inhibiting HDAC6. The compound provided by the invention can significantly inhibit HDAC6, the IC50 value of the compound is at a nanomole level, the dosage of apatient is favorably reduced, and the toxic and side effects of the medicine on a human body are reduced. The compound provided by the invention has high selectivity on subtype HDAC1, can effectivelyavoid toxic and side effects of a drug on normal tissues of a human body, and shows good development potential.
- -
-
Paragraph 0036-0038
(2021/01/29)
-
- Identification of novel 1,3-diaryl-1,2,4-triazole-capped histone deacetylase 6 inhibitors with potential anti-gastric cancer activity
-
Histone deacetylase 6 (HDAC6) has emerged as a critical regulator of many cellular pathways in tumors due to its unique structure basis and abundant substrate types. Over the past few decades, the role played by HDAC6 inhibitors as anticancer agents has sparked great interest of biochemists worldwide. However, they were less reported for gastric cancer therapy. In this paper, with the help of bioisosteric replacement, in-house library screening, and lead optimization strategies, we designed, synthesized and verified a series of 1,3-diaryl-1,2,4-triazole-capped HDAC6 inhibitors with promising anti-gastric cancer activities. Amongst, compound 9r displayed the best inhibitory activity towards HDAC6 (IC50 = 30.6 nM), with 128-fold selectivity over HDAC1. Further BLI and CETSA assay proved the high affinity of 9r to HDAC6. In addition, 9r could dose-dependently upregulate the levels of acetylated α-tubulin, without significant effect on acetylated histone H3 in MGC803 cells. Besides, 9r exhibited potent antiproliferative effect on MGC803 cells, and promoted apoptosis and suppressed the metastasis without obvious toxicity, suggesting 9r would serve as a potential lead compound for the development of novel therapeutic agents of gastric cancer.
- Zhang, Xin-Hui,Kang, Hui-Qin,Tao, Yuan-Yuan,Li, Yi-Han,Zhao, Jun-Ru,Ya-Gao,Ma, Li-Ying,Liu, Hong-Min
-
-
- Mn(III)-mediated phosphinoylation of aldehyde hydrazones: Direct “one-pot” synthesis of α-iminophosphine oxides from aldehydes
-
A “one-pot” strategy for the straightforward Mn(III)-mediated phosphinoylation of aldehyde hydrazones with diphenylphosphine oxide to furnish α-iminophosphine oxides is described. This mild and practical method allows the direct use of aldehydes as substrates in one pot to generate the hydrazones, which are then engaged “in situ” by the phosphorus reagent in the presence of Mn(OAc)3 oxidant. Thus, the requisite isolation of the hydrazones is not needed in this operation. Conducted mechanistic experiments implicate a pathway involving phosphorus-centered radicals.
- Bian, Xue-Wei,Zhang, Ling,Shoberu, Adedamola,Zou, Jian-Ping
-
supporting information
(2021/04/02)
-
- Sequential [3+2] annulation reaction of prop-2-ynylsulfonium salts and hydrazonyl chlorides: Synthesis of pyrazoles containing functional motifs
-
A novel sequential [3+2] annulation reaction has been developed using prop-2-ynylsulfonium salts and hydrazonyl chlorides, affording a series of pyrazoles with functional motifs that can be post modified in the preparation of various drugs or drug candidates. Further transformation and gram-scale operations could also be achieved efficiently. This journal is
- Jia, Tingting,Liu, Shourong,Shao, Jiaan,Shi, Tao,Wu, Zhaoxiao,Zeng, Linghui,Zhang, Chong,Zhang, Jiankang,Zhu, Huajian,Zhuang, Rangxiao
-
supporting information
p. 8460 - 8463
(2021/09/08)
-
- Synthesis of 1,1′-([1,1′-Biphenyl]-4,4′-diyl)bis(3-aryl-5-phenylformazans) and 1,1′-([1,1′-Biphenyl]-4,4′-diyl)bis(3-aryl-5-phenyl-5,6-dihydro-1,2,4,5-tetrazin-1-ium) Perchlorates
-
Abstract: New bis-formazans and bis(5,6-dihydro-1,2,4,5-tetrazin-1-ium) perchlorates were synthesized with high yields under mild conditions. 1,1′-([1,1′-Biphenyl]-4,4′-diyl)bis(3-aryl-5-phenylformazans) were obtained by diazo coupling of para-substituted benzaldehyde phenylhydrazones with [1,1′-biphenyl]-4,4′-bis(diazonium chloride). Treatment of the obtained bis-formazans with formaldehyde in the presence of perchloric acid in dioxane afforded 1,1′-([1,1′-biphenyl]-4,4′-diyl)bis(3-aryl-5-phenyl-5,6-dihydro-1,2,4,5-tetrazin-1-ium) diper-chlorates. The structure of the synthesized compounds was confirmed by elemental analyses and UV, IR, and 1H and 13C NMR spectra.
- Alalwan, D. H. K.,Jassim, T.,Kostryukov, S. G.,Kozlov, A. Sh.,Masterova, Yu. Yu.,Tezikova, V. S.
-
p. 1600 - 1607
(2021/12/13)
-
- Broad-Spectrum Antifungal Agents: Fluorinated Aryl- and Heteroaryl-Substituted Hydrazones
-
Fluorinated aryl- and heteroaryl-substituted monohydrazones displayed excellent broad-spectrum activity against various fungal strains, including a panel of clinically relevant Candida auris strains relative to a control antifungal agent, voriconazole (VRC). These monohydrazones displayed less hemolysis of murine red blood cells than that of VRC at the same concentrations, possessed fungicidal activity in a time-kill study, and exhibited no mammalian cell cytotoxicity. In addition, these monohydrazones prevented the formation of biofilms that otherwise block antibiotic effectiveness and did not trigger the development of resistance when exposed to C. auris AR Bank # 0390 over 15 passages.
- Thamban Chandrika, Nishad,Dennis, Emily K.,Brubaker, Katelyn R.,Kwiatkowski, Stefan,Watt, David S.,Garneau-Tsodikova, Sylvie
-
supporting information
p. 124 - 133
(2020/10/20)
-
- Nitrogen-modified graphene as a metal-free carbocatalyst for the solvent-free oxidative homo- and heterocoupling of amines
-
In this study, graphene oxide (GO) has been prepared using Hammers’ method and the produced GO was converted to nitrogen-modified GO (NGO) using hydrothermal reaction with ammonia and hydrazine. The morphology of the product was confirmed with FESEM images and XRD, TEM, Raman, TGA, EDS, BET and FTIR analyses were employed to study the structure and properties of the product. The produced NGO has been employed as a catalyst for oxidative coupling of amines to imines. The reaction was carried out at 110?°C, using 4 wt% of catalyst (versus the used amine), oxygen gas as oxidative agent, solvent-free condition in 4?h with 80% yield. To determine the versatility of the reaction, different derivatives of amines such as benzylamine, phenyl hydrazine, aniline, ethylenediamine, ethanol amine and homoveratrylamine have been examined in this reaction and successfully converted to the related imines via heterocoupling reactions. Finally, the recyclability of the reaction was investigated and the results showed only 10% decreasing in the yield after 6 runs.
- Ganbari, Alireza,Tavakol, Hossein
-
-
- Polyaromatic hydrocarbon derivatized azo-oximes of cobalt(iii) for the ligand-redox controlled electrocatalytic oxygen reduction reaction
-
A pair of ligands HLPyr1a and HLAnc1b (Pyr = pyrene, Anc = anthracene) incorporating π-electron-rich polycyclic aromatic hydrocarbons (PAHs), viz. pyrene and anthracene moieties respectively, in conjunction with electron-poor azo-oxime groups was synthesized. The tris complexes [CoIII(LPyr)3] 2a and [CoIII(LAnc)3] 2b were also prepared and structurally authenticated by X-ray diffraction. They exhibit significant redox and optoelectronic properties, which were analyzed by density functional theory (DFT) and time dependent density functional theory (TD-DFT). Theoretical investigation further revealed that the coordinated ligands act as superior electron reservoirs in comparison to the free ligands and transfer electrons through the PAH moieties. This property was smartly exploited to scrutinize the aptitude of the cobalt(iii) complexes for the electrocatalytic oxygen reduction reaction (ORR). The catalytic process proceeds via a 4-electron transfer pathway to form hydroxide ions in alkaline medium. The role of the PAHs in the complexes 2a and 2b in providing a pool of electrons was further emphasized via substituting them with phenyl groups, as in [CoIII(LPh)3] 2c, when the catalytic ORR activity was significantly diminished. Moreover, the activity was completely lost when the PAHs were replaced by methyl groups, as in [CoIII(LMe)3] 2d.
- Dinda, Soumitra,Roy, Syamantak,Patra, Sarat Chandra,Bhandary, Subhrajyoti,Pramanik, Kausikisankar,Ganguly, Sanjib
-
p. 3737 - 3747
(2020/03/17)
-
- From Phenylhydrazone to 1H-1,2,4-Triazoles via Nitrification, Reduction and Cyclization
-
Herein we report an annulation of phenylhydrazone via a tandem nitrification, reduction, cyclization protocol employing cobalt nitrate and 1,2-dichloroethane to produce substituted 1H-1,2,4-triazoles. Notably, 1,2-dichloroethane serves both the solvent and a hydrogen source for transfer hydrogenation. This methodology works under mild conditions, providing a direct approach for the synthesis of 1H-1,2,4-triazoles. (Figure presented.).
- Hao, Liqiang,Wang, Guodong,Sun, Jian,Xu, Jun,Li, Hongshuang,Duan, Guiyun,Xia, Chengcai,Zhang, Pengfei
-
supporting information
p. 1657 - 1662
(2020/03/19)
-
- Transition-Metal-Free Coupling of 1,3-Dipoles and Boronic Acids as a Sustainable Approach to C?C Bond Formation
-
The need for alternative, complementary approaches to enable C?C bond formation within organic chemistry is an on-going challenge in the area. Of particular relevance are transformations that proceed in the absence of transition-metal reagents. In the current study, we report a comprehensive investigation of the coupling of nitrile imines and aryl boronic acids as an approach towards sustainable C?C bond formation. In situ generation of the highly reactive 1,3-dipole facilitates a Petasis–Mannich-type coupling via a nucleophilic boronate complex. The introduction of hydrazonyl chlorides as a complementary nitrile imine source to the 2,5-tetrazoles previously reported by our laboratory further broadens the scope of the approach. Additionally, we exemplify for the first time the extension of this protocol into another 1,3-dipole, through the synthesis of aryl ketone oximes from aryl boronic acids and nitrile N-oxides.
- Livingstone, Keith,Bertrand, Sophie,Kennedy, Alan R.,Jamieson, Craig
-
supporting information
p. 10591 - 10597
(2020/07/25)
-
- Triarylverdazyl radicals as promising redox-active components of rechargeable organic batteries
-
A novel design of electroactive components of rechargeable organic batteries based on stable verdazyl radicals bearing various substituents is proposed. 3-Positioned aromatic substituents at the verdazyl moiety affect the reduction potentials and almost do not affect the oxidation potential, while 1-positioned aromatic substituents affect contrariwise the oxidation potential of this radical without any influence on the reduction potential. The acquired electrochemical data allowed us to reveal the structure—potential relationship for the cathodic and anodic processes, which provided the design of triarylverdazyl radicals possessing record-breaking parameters of the “electrochemical gap”.
- Burtasov, A. A.,Chernyaeva, O. Yu.,Kostryukov, S. G.,Kozlov, A. Sh.,Pryanichnikova, M. K.,Tanaseichuk, B. S.
-
p. 1321 - 1328
(2020/09/07)
-
- Synthesis and Electrochemical Properties of 2-(4-R1-Phenyl)-6-(4-R2-phenyl)-4-phenyl-3,4-dihydro1,2,4,5-tetrazin-1(2H)-yls
-
Abstract: A new methodology for creating electroactive components for organic batteries,based on the construction of a molecular platform including stable3,4-dihydro-1,2,4,5-tetrazin-1(2H)-ylradicals was described. A series of2-(4-R1-phenyl)-6-(4-R2-phenyl)-4-phenyl-3,4-dihydro-1,2,4,5-tetrazin-1(2H)-yls with substituents of various nature wasobtained. It was shown that the substituents R1 inthe aromatic ring at position 2 of the tetrazinyl fragment influence the valueof the oxidation potential in the radical, but do not influence the value of thereduction potentials, while the substituent R2 of thearomatic ring at position 6 influence the values of the reduction potentials andpractically do not influence oxidation potential values. Based on the obtainedelectrochemical data, a correlation structure–potential value was revealed forthe cathodic and anodic process, with the help of which triarylsubstituted3,4-dihydro-1,2,4,5-tetrazin-1(2H)-ylradicals with high values of the electrochemical gap were obtained.
- Akhmatova, A. A.,Balandina, A. V.,Chernyaeva, O. Yu.,Kostryukov, S. G.,Kozlov, A. Sh.,Kraynov, E. V.,Lukshina, Yu. I.,Pryanichnikova, M. K.
-
p. 341 - 351
(2020/04/27)
-
- Shaken, not stirred: a schools test for aldehydes and ketones
-
A schools test for aldehydes and ketones in water at room temperature using test tubes has been developed in this laboratory using either phenylhydrazine hydrochloride or phenylhydrazine hydrochloride with NaOAc . 3H2O. The role of one equivalent of a strong or weak acid which catalyses the reaction is discussed.
- Plater, M John
-
p. 104 - 107
(2019/11/22)
-
- Facile One-Pot Transformation of Primary Alcohols into 3-Aryl- and 3-Alkyl-isoxazoles and -pyrazoles
-
Various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylisoxazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, NH 2 OH, and then NCS, followed by reaction with alkynes in the presence of Et 3 N. Similarly, various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylpyrazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, PhNHNH 2, and then NCS and decyl methyl sulfide, followed by reaction with alkynes in the presence of Et 3 N. Thus, both 3-aryl- and 3-alkylisoxazoles, and 3-aryl- and 3-alkylpyrazoles could be prepared from readily available primary alcohols in one pot under transition-metal-free conditions.
- Kobayashi, Eiji,Togo, Hideo
-
p. 3723 - 3735
(2019/09/30)
-
- One-pot synthesis of 1,3,4-oxadiazol-2(3H)-ones with CO2 as a C1 synthon promoted by hypoiodite
-
A convenient and efficient route has been developed to synthesize 1,3,4-oxadiazol-2(3H)-ones from CO2, hydrazines and aryl or aliphatic aldehydes. Promoted by hypoiodite (IO-) generated in situ from KI and oxidant TBHP, the one-pot synthesis could proceed smoothly to afford the desired products in moderate to high yields. Mechanism studies revealed that nitrile imine was an important intermediate in this transformation. Notably, a commercial herbicide Oxadiazon could be successfully synthesized by this route.
- Yang, Na,Yuan, Gaoqing
-
p. 6639 - 6644
(2019/07/16)
-
- Copper catalysed cross-dehydrogenative coupling (CDC) reaction of 4-thiazolidinone with terminal alkyne
-
Cross dehydrogenative coupling (CDC) strategy has been employed for C-alkynylation of 4-thiazolidinone with terminal alkyne under copper catalysis. Present reaction involves coupling of C(sp3) adjacent to sulfur of 4-thiazolidinone with C(sp) of terminal alkyne under CDC strategy is unprecedented to the best of our knowledge. Significant functional group tolerance, considerable yield and DFT study for mechanism make this synthetic task more interesting and compatible.
- Shaikh, Mohammedumar M.,Patel, Anuj P.,Chikhalia, Kishor H.
-
p. 475 - 485
(2019/01/04)
-
- Experimental and quantum chemical studies of the structural and spectral properties of novel diazenyl formazans
-
A new series of 3-(p-substitutedphenyl)-5-phenyl-1-(4-phenyldiazenyl)phenylformazans were synthesized by coupling p-substituted phenyl or pyridinylhydrazones with p-aminoazobenzene diazonium chloride. All compounds were characterized by FT-IR, UV–Vis, 1H NMR, and 13C NMR spectroscopic techniques, and HR-MS. DFT was used to calculate the molecular structures and 1H and 13C chemical shift values of the synthesized compounds with PBE1PBE functional and 6-311G(2d,2p)basis set combination. The IR spectra of the novel formazans were calculated using DFT at PBE1PBE/6-311G(d,p)level of theory. The electronic absorption spectra of the optimized structures were evaluated by TD-DFT method at PBE1PBE/6-311G(2d,2p)level of theory. The absorption spectra of the synthesized diazenyl formazans were investigated in three different solvents. A good correlation was established between the experimental data and calculated results.
- Tezcan, Habibe,?en?z, Hülya,Tokay, Nesrin
-
p. 171 - 183
(2019/04/29)
-
- Synthesis of hybrid polycycles containing fused hydroxy benzofuran and 1H-indazoles via a domino cyclization reaction
-
A stoichiometry controlled domino cyclization reaction of hydrazone and p-benzoquinone to an angularly fused 3H-benzofuro[3,2-e]indazole core with an embedded oxygenated dibenzofuran framework under mild reaction conditions is disclosed. The reaction involves palladium catalyzed 5-hydroxy-1H-indazole formation followed by TFA mediated [3+2] annulation between the in situ formed 5-hydroxy-1H-indazole and p-benzoquinone. The developed method is attractive because of the concomitant formation of two heterocyclic rings with consecutive multiple bond forming events that include two C-C, one C-N and one C-O bonds. Spectroscopic and theoretical studies of the blue emissive benzofuroindazole derivatives have also been described.
- Janardhanan, Jith C.,James, Kiran,Puthuvakkal, Anisha,Bhaskaran, Rasmi P.,Suresh, Cherumuttathu H.,Praveen, Vakayil K.,Manoj, Narayanapillai,Babu, Beneesh P.
-
p. 10166 - 10175
(2019/07/03)
-
- The use of enaminones and enamines as effective synthons for MSA-catalyzed regioselective synthesis of 1,3,4-tri- And 1,3,4,5-tetrasubstituted pyrazoles
-
In the present work, an efficient regioselective synthesis of 1,3,4-tri- and 1,3,4,5-tetrasubstituted pyrazoles via a methanesulfonic acid (MSA)-catalyzed reaction of hydrazones with enaminones or enamines is reported. Mechanistically, the formation of the title compounds involves the [2+3] cycloaddition of hydrazones with enaminones or enamines followed by aromatization with acid and oxygen. This convenient method under mild conditions with various hydrazones, enaminones, and enamines was well-tolerated to afford products in good to excellent yields. Compared with the literature methods, this strategy has advantages such as materials that are available economically, metal-free catalysis, excellent regioselectivity, and high efficiency.
- Duan, Liancheng,Zhou, Hui,Gu, Yucheng,Gong, Ping,Qin, Mingze
-
supporting information
p. 16131 - 16137
(2019/11/03)
-
- Lewis acid–catalyzed green synthesis and biological studies of pyrrolo[3,4-c]pyrazoles in aqueous medium
-
An environmentally benign approach in aqueous medium by means of Lewis acid catalyst affords a wide spectrum of pyrazoline derivatives in satisfactory yields. [3+2] cycloaddition reactions of substituted azomethine-N-imines to maleimide in aqueous medium at relatively high concentrations of Lewis acid catalyst have emerged as an environment friendly alternative to conventional solvents. Promising catalytic activity has been revealed by Lewis acid like Cu (NO3)2 in aqueous medium. The obvious features of this synthetic protocol were short reaction time, high efficiency, less hazardous synthesis by benign solvent, catalysis, modest workup, and a clean reaction methodology.
- Arjuna, Anania,Kaur, Manpreet,Singh, Baldev
-
-
- N-Aminations of Benzylamines and Alicyclic Amines with Nitrosoarenes to Hydrazones and Hydrazides
-
Unlike other alkylamines, benzylamines upon reaction with a nitrosoarene undergo oxidation to the corresponding imines. A direct amination of benzylamines, which was difficult to achieve due to its facile oxidation, to the corresponding hydrazones is reported. A wide variety of benzylamines and N-heterocycles were reacted with nitrosoarenes to provide structurally diverse hydrazones and hydrazides, respectively. Moreover, the direct N-amination reaction was applied to the one-pot synthesis of triazoles.
- Jana, Chandan K.,Purkait, Anisha
-
p. 2687 - 2696
(2019/06/19)
-
- sp2-C–H Acetoxylation of Diversely Substituted (E)-1-(Arylmethylene)-2-phenylhydrazines Using PhI(OAc)2 as Acetoxy Source at Ambient Conditions
-
A catalyst- and additive-free simple and straightforward method for regioselective direct sp2 C–H acetoxylation reaction of aldehyde hydrazones has been achieved at ambient temperature employing PIDA as an acetoxy source. The scope of the reaction has been successfully verified with a wide range of biologically important aldehyde hydrazones with diverse functional group tolerance. The method is highly selective, mild and efficient, operationally simple, rapid and high-yielding.
- Brahmachari, Goutam,Karmakar, Indrajit
-
supporting information
p. 5925 - 5933
(2019/08/16)
-
- Stereospecific copper(II)-catalyzed tandem ring opening/oxidative alkylation of donor-acceptor cyclopropanes with hydrazones: Synthesis of tetrahydropyridazines
-
Aerobic copper(II)-catalyzed tandem ring opening and oxidative C-H alkylation of donor-acceptor cyclopropanes with bisaryl hydrazones is accomplished to produce tetrahydropyridazines, in which copper(II) plays dual role as a Lewis acid as well as redox catalyst. The reaction is stereospecific, and optically active cyclopropanes can be reacted with high optical purities (89-98% enantiomeric excess). The substrate scope, functional group tolerance, dual role of the copper(II) catalyst, and the use of air as an oxidant are the important practical features. A product bearing a 3-bromoaryl group can be subjected to Pd-catalyzed Suzuki coupling with boronic acid in high yield.
- Mishra, Manmath,De, Pinaki Bhusan,Pradhan, Sourav,Punniyamurthy, Tharmalingam
-
p. 10901 - 10910
(2019/09/13)
-
- Electrochemical synthesis of 1,2,4-triazole-fused heterocycles
-
A reagent-free intramolecular dehydrogenative C-N cross-coupling reaction has been developed under mild electrolytic conditions. In this atom- and step-economical one-pot process, valuable 1,2,4-triazolo[4,3-a]pyridines and related heterocyclic compounds could be synthesized efficiently from commercially available aliphatic or (hetero)aromatic aldehydes and 2-hydrazinopyridines. Various functional groups are compatible with this metal- and oxidant-free protocol which can be carried out on a gram scale easily. This novel method was applied to the synthesis of one of the top-selling drugs Xanax and late stage functionalization for generating chemical diversity in biologically relevant lead molecules.
- Ye, Zenghui,Ding, Mingruo,Wu, Yanqi,Li, Yong,Hua, Wenkai,Zhang, Fengzhi
-
supporting information
p. 1732 - 1737
(2018/04/30)
-
- Verdazyl Radical Building Blocks: Synthesis, Structure, and Sonogashira Cross-Coupling Reactions
-
A general and effective method for the synthesis of 3-phenylveradzyl radicals bearing a variety of iodophenyl substituents has been developed. The synthesized radicals have been characterized by ESR, UV/Vis spectroscopy, and cyclic voltammetry. Structures of biphenyl-substituted radicals have been solved by X-ray crystal structure analysis. The synthesized iodoverdazyls are applicable in the Sonogashira coupling reaction for the preparation of a wide range of ethynyl derivatives. Both N-2 and C-6 substituents were functionalized through Sonogashira coupling.
- Petunin, Pavel V.,Martynko, Ekaterina A.,Trusova, Marina E.,Kazantsev, Maxim S.,Rybalova, Tatyana V.,Valiev, Rashid R.,Uvarov, Mikhail N.,Mostovich, Evgeny. A.,Postnikov, Pavel S.
-
supporting information
p. 4802 - 4811
(2018/09/21)
-
- Facile synthesis of pyrazoles by iron-catalyzed regioselective cyclization of hydrazone and 1,2-diol under ligand-free conditions
-
A facile synthesis of pyrazoles by the cyclization of hydrazones and 1,2-diols was described. In the presence of ferric nitrate, the reaction occurs under neat conditions and makes the use of potassium persulfate to oxidize the diol to α-hydroxy carbaldehyde for the reaction with hydrazones to produce 1,3- and 1,3,5-substituted pyrazoles selectively. The overall regioselective transformation occurs in one-pot under ligand-free, mild conditions even in the presence of air.
- Panda, Niranjan,Ojha, Subhadra
-
p. 244 - 251
(2018/03/13)
-
- Exceptionally rapid oxime and hydrazone formation promoted by catalytic amine buffers with low toxicity
-
Hydrazone and oxime bond formation between α-nucleophiles (e.g. hydrazines, alkoxy-amines) and carbonyl compounds (aldehydes and ketones) is convenient and is widely applied in multiple fields of research. While the reactants are simple, a substantial drawback is the relatively slow reaction at neutral pH. Here we describe a novel molecular strategy for accelerating these reactions, using bifunctional buffer compounds that not only control pH but also catalyze the reaction. The buffers can be employed at pH 5-9 (5-50 mM) and accelerate reactions by several orders of magnitude, yielding second-order rate constants of >10 M-1 s-1. Effective bifunctional amines include 2-(aminomethyl)imidazoles and N,N-dimethylethylenediamine. Unlike previous diaminobenzene catalysts, the new buffer amines are found to have low toxicity to human cells, and can be used to promote reactions in cellular applications.
- Larsen, Dennis,Kietrys, Anna M.,Clark, Spencer A.,Park, Hyun Shin,Ekebergh, Andreas,Kool, Eric T.
-
p. 5252 - 5259
(2018/06/21)
-
- Aniline Catalysed Hydrazone Formation Reactions Show a Large Variation in Reaction Rates and Catalytic Effects
-
Hydrazone formation reactions from aldehydes and hydrazides have the remarkable qualities that they proceed in water and the kinetics can be controlled by organocatalysis. For these reasons, this class of reactions finds widespread use in biological as well as material settings. We recently reported a protected aniline catalyst for hydrazone formation that can be activated using a chemical signal. In our search to find a suitable hydrazone formation reaction to investigate the activation of this pro-catalyst, we found a wide variety in reaction rates and response to catalysis. Here we report an overview of hydrazone formation reactions, their reaction rates and response to aniline catalysis, their compatibility for kinetic analysis by UV/Vis spectroscopy, and their compatibility with the reaction environment and with the pro-catalyst pro-aniline. (Figure presented.).
- Trausel, Fanny,Fan, Bowen,van Rossum, Susan A. P.,van Esch, Jan H.,Eelkema, Rienk
-
p. 2571 - 2576
(2018/05/30)
-
- Ion-pairing catalysis in the enantioselective addition of hydrazones to N-acyldihydropyrrole derivatives
-
We have demonstrated that dihydropyrrole-based enamide derivatives can act as efficient precursors of chiral quaternary N-acyliminium salts under Br?nsted acid catalysis that undergo reactions with hydrazones, the latter participating as masked nucleophilic carbonyl group equivalents. The optimized methodology provides a variety of enantiopure α-substituted proline derivatives in excellent yields, being even compatible with disubstituted β-enamides that generate two contiguous stereocentres.
- Zabaleta, Nagore,Uria, Uxue,Reyes, Efraim,Carrillo, Luisa,Vicario, Jose L.
-
supporting information
p. 8905 - 8908
(2018/08/17)
-
- Synthesis and evaluation of anti-Tuberculosis and anti-cancer activities of hydrazones and N-Acylhydrazones by using sonochemistry, a new general procedure
-
Background: In continuation of our research on sonochemistry and due to the importance and application of hydrazones and N-Acylhydrazones in drug discovery, in this work we report a new general and efficient synthesis of these classes with different aromatic and heteroaromatic nucleus assisted by ultrasound and their respective anti-Tuberculosis and anti-cancer activities. Method: Derivatives 7-chloroquinoline 10 and 12 were the most promising compounds against cancer and TB, respectively. Conclusion: Unfortunately all new hydrazones and N-Acylhydrazones evaluated displayed no activity anti cancer and TB.
- Da Silveira Pinto, Ligia S.,De Souza, Marcus V. N.,Kaiser, Carlos R.
-
p. 678 - 685
(2017/07/15)
-
- Efficient Method for Aromatic-Aldehyde Oxidation by Cleavage of Their Hydrazones Catalysed by Trimethylsilanolate
-
The reactions of hydrazones, derived from various aromatic aldehydes bound to Rink resin and hydrazines, with trimethylsilanolate have been studied. In this process, the aldehydes were oxidized to the corresponding carboxylic acids. The reaction was also tested with success in solution, with various aromatic aldehydes easily being oxidized in one pot via hydrazone formation and trimethylsilanolate treatment. A mechanism for the hydrazone cleavage is proposed. The reaction may be used as an alternative method for aldehyde oxidation with the selectivity complementary to that of currently used reactions.
- Burglova, Kristyna,Okorochenkov, Sergei,Budesinsky, Milos,Hlavac, Jan
-
p. 389 - 396
(2017/01/24)
-
- Spirotriazoline oxindoles: A novel chemical scaffold with in vitro anticancer properties
-
The design and synthesis of a library of twenty-six spirotriazoline oxindoles and their in vitro evaluation as potential anticancer agents is reported. The antiproliferative activity of the synthesized compounds was assessed against four different cancer cell lines (HCT-116 p53 (+/+), HCT-116 p53 (?/?), MCF-7, and MDA-MB-231). Four spirotriazoline oxindoles showed selectivity against the four cancer cell lines tested over the non-cancer derived HEK 293T cell line. To characterize the molecular mechanisms involved in compound antitumoral activity, two spirotriazoline oxindoles were selected for further studies. Both compounds were able to induce apoptosis and cell cycle arrest at G0/G1 phase and upregulated p53 steady-state levels, while decreasing its main inhibitor MDM2, in HCT-116 cells. Importantly, cytotoxic effects induced by spirotriazoline oxindoles occurred in cancer cells without eliciting cell death in non-malignant CCD-18Co human colon fibroblasts. In addition, four spirotriazoline oxindoles showed selectivity against the triple-negative breast cancer cell line MDA-MB-231 with IC50 values of 3.5–6.7 μM. These results highlight the anticancer potential of spirotriazoline oxindoles, especially when dealing with aggressive and challenging triple-negative breast cancer.
- Ribeiro, Carlos J.A.,Nunes, Rute C.,Amaral, Joana D.,Gon?alves, Lídia M.,Rodrigues, Cecília M.P.,Moreira, Rui,Santos, Maria M.M.
-
p. 494 - 509
(2017/10/10)
-
- Simple and efficient approach for synthesis of hydrazones from carbonyl compounds and hydrazides catalyzed by meglumine
-
A simple, environmentally benign protocol for synthesis of hydrazones from carbonyl compounds and hydrazides has been developed in the presence of meglumine in aqueous-ethanol media at room temperature. The salient features of the present protocol are mild reaction conditions, short reaction time, high yields, operational simplicity, metal-free, applicability toward large-scale synthesis, and biodegradable and inexpensive catalyst.
- Zhang, Mo,Shang, Ze-Ren,Li, Xiao-Tang,Zhang, Jia-Nan,Wang, Yong,Li, Kang,Li, Yang-Yang,Zhang, Zhan-Hui
-
p. 178 - 187
(2017/01/10)
-
- Transition-Metal-Free Trifluoromethylation of Aldehyde Derivatives with Sodium Trifluoromethanesulfinate
-
A metal-free and cost-effective synthetic protocol for the trifluoromethylation of N,N-disubstituted hydrazones with Langlois's reagent (CF3SO2Na) to afford the corresponding functionalized trifluoromethyl ketone hydrazones has been established. It is proposed that a radical/SET mechanism proceeding via a trifluoroalkyl radical may be involved in the reaction. Applications of the methodology in industry will be found and the development of new methods for trifluoromethylation with Langlois's reagent will be continued in our laboratory.
- Tan, Zheng,Zhang, Shiwei,Zhang, Yan,Li, Yunpeng,Ni, Minjie,Feng, Bainian
-
p. 9384 - 9399
(2017/09/23)
-
- The Effect of Oxidizing Agents in the Preparation of 2,3,5-triaryl-2H-tetrazolium Salts from 1,3,5-triarylformazans
-
Tetrazolium salts are a group of versatile molecules with a relatively limited application due to synthesis difficulty and high cost of production. Here, we have comparatively examined several approaches for the preparation of 2-(4-nitrophenyl)-3,5-diphenyl-2H-tetrazolium chloride (NTC), as a model tetrazolium salt, through the oxidation of 1-(4-nitrophenyl)-3,5-diphenylformazan (NF), by means of interphase oxidation, dehydrogenation, and direct chlorination. Our findings indicate that chlorination of NF with 1-chlorobenztriazole to be the best choice to prepare NTC from small-scale and scaled-up considerations.
- Penev, Kalin I.,Mequanint, Kibret
-
p. 1655 - 1660
(2016/09/23)
-
- 1,4-Bis-Dipp/Mes-1,2,4-Triazolylidenes: Carbene Catalysts That Efficiently Overcome Steric Hindrance in the Redox Esterification of α- And β-Substituted α,β-Enals
-
As reported by Scheidt and Bode in 2005, sterically nonencumbered α,β-enals are readily converted to saturated esters in the presence of alcohols and N-heterocyclic carbene catalysts, e.g., benzimidazolylidenes or triazolylidenes. However, substituents at the α- or β-position of the α,β-enal substrate are typically not tolerated, thus severely limiting the substrate spectrum. On the basis of our earlier mechanistic studies, a set of N-Mes- or N-Dipp-substituted 1,2,4-triazolium salts were synthesized and evaluated as (pre)catalysts in the redox esterification of various α- or β-substituted enals. In particular the 1,4-bis-Mes/Dipp-1,2,4-triazolylidenes overcome the above limitations and efficiently catalyze the redox esterification of a whole series of α/β-substituted enals hitherto not amenable to NHC-catalyzed transformations. The synthetic value of 1,4-bis-Mes/Dipp-1,2,4-triazolylidenes is further demonstrated by the one-step bicyclization of 10-oxocitral to (racemic) nepetalactone in diastereomerically pure form.
- Yatham, Veera Reddy,Harnying, Wacharee,Kootz, Darius,Neud?rfl, J?rg-M.,Schl?rer, Nils E.,Berkessel, Albrecht
-
supporting information
p. 2670 - 2677
(2016/03/12)
-
- Fe+3-montmorillonite K10 as an Efficient Reusable Heterogeneous Catalyst for the Grind Mediated Synthesis of 14-aryl-14H-dibenzo [a,j]xanthenes
-
Background: Xanthenes are an important class of organic compounds and have also received significant attention due to their wide range of pharmacological activities such as antibacterial, antiviral, antiinflammatory activities, antagonists for the paralyzing action of zoxazolamine and efficiency in photodynamic therapy, a well-known method for controlling the localized tumors. Natural sources are also rich of xanthene compounds. Popularly known pigments, santalin have been isolated from plant species. Furthermore, these compounds can be emerged as pH-sensitive fluorescent materials for visualization of biomolecules, in laser technologies and as dyes. There are several reports in the literature for the synthesis of xanthenes such as alkylations of heteroatoms, cyclodehydrations, cyclocondensations between 2-hydroxyaromatic aldehydes and 2- tetralone, trapping of benzynes by phenols and intramolecular phenyl-carbonyl coupling reactions of benzaldehydes and acetophenones bearing tethered carbonyl chains in the presence of hexamethylphosphoramide and SmI2. Other methods for the synthesis of xanthenes include the reaction of formamide with β-naphthol, carbon monoxide, and 1- hydroxymethyl-naphthalen-2-ol. Methods: procedure a: A mixture of substituted benzaldehyde, 2-naphtol and Fe+3-montmorillonite K10 was mixed. After completion of the reaction, the product was solved in CHCl3 (3×10 mL) and insoluble catalyst was removed by filtration. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. procedure b: A mixture of substituted benzaldehyde, phenylhydrazine and Fe+3-montmorillonite K10 were added to a mortar and the mixture was pulverized with a pestle. After completion of the reaction, 2-naphtol was added to the consulting mixture and pulverized with a pestle. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. Results: As part of our going interest for the development of efficient and environmentally friendly procedures for the synthesis of heterocyclic and pharmaceutical compounds, we wish to report the first grind mediated synthesis of some derivatives of xanthenes using catalytic amount of Fe+3-montmotillonite. Conclusion: In conclusion, we have investigated the Fe+3-montmorillonite K10 under grinding as a mild and efficient catalyst for the synthesis of substituted 14-aryl-14H-dibenzo [a,j]xanthenes. The remarkable advantages offered by this method are: catalyst is inexpensive, non-toxic, easy handling and reusability, simple work-up procedure, short reaction time, high yields of product with better purity and green aspect by avoiding toxic catalyst and hazardous solvent.
- Fekri, Leila Z.,Nikpassand, Mohammad,Fard, Hajar S.,Marvi, Omid
-
p. 135 - 142
(2016/03/01)
-
- A Single Electron Transfer (SET) Approach to C-H Amidation of Hydrazones via Visible-Light Photoredox Catalysis
-
The reductive single electron transfer (SET) umpolung amination of aldehyde-derived hydrazones has been developed through visible-light-promoted photoredox catalysis. The ideal transformation of hydrazones into the corresponding hydrazonamide through selective carbon-hydrogen (C-H) bond functionalization represents one of the most step- and atom-economical methods. This SET umpolung strategy features mild conditions and a remarkably broad substrate scope, offering an entirely new substrate class to direct C-H amination.
- Zhang, Muliang,Duan, Yingqian,Li, Weipeng,Xu, Pan,Cheng, Jian,Yu, Shouyun,Zhu, Chengjian
-
supporting information
p. 5356 - 5359
(2016/11/02)
-
- A Study of Boratriazaroles: An Underdeveloped Class of Heterocycles
-
Boratriazaroles were discovered in the late 1960s, and since then, a variety of substituted boratriazarole derivatives have been prepared. However, no study has compared the properties of these BN heterocycles with their carbon-based analogues. In this work, we have prepared a series of boratriazarole derivatives and have investigated how structural variations in the five-member heterocycle affect photophysical and electronic properties. Boratriazaroles exhibit absorption and emission spectra comparable to those of their azacycle analogues but have a markedly lower quantum yield. The quantum yield can be increased with the incorporation of a 2-pyridyl substitution on the boratriazaroles, and the structural and optoelectronic properties are further influenced by the nature of the B-aryl substituent. Introducing an electron-deficient p-cyano group on the B-phenyl substituent creates a twisted intramolecular charge transfer state that causes a large Stokes shift and positive solvatochromism. Our work should serve to guide future synthetic efforts toward the application of boratriazaroles in materials science.
- Liew, Sean K.,Holownia, Aleksandra,Tilley, Andrew J.,Carrera, Elisa I.,Seferos, Dwight S.,Yudin, Andrei K.
-
p. 10444 - 10453
(2016/11/17)
-
- Copper-catalyzed synthesis of 1,3,4-trisubstituted and 1,3,4,5-tetrasubstituted pyrazoles via [3+2] cycloadditions of hydrazones and nitroolefins
-
A highly economical and efficient copper(I)-catalyzed regioselective method for the synthesis of 1,3,4-trisubstituted and 1,3,4,5-tetrasubstituted pyrazoles via [3+2] cycloaddition of hydrazones and nitroolefins has been reported. This process displays excellent applicability with a wide range of substrates under mild conditions.
- Shi, Chong,Ma, Chaowei,Ma, Haojie,Zhou, Xiaoqiang,Cao, Jinhui,Fan, Yuxing,Huang, Guosheng
-
supporting information
p. 4055 - 4058
(2016/07/06)
-
- Radical Addition of Hydrazones by α-Bromo Ketones to Prepare 1,3,5-Trisubstituted Pyrazoles via Visible Light Catalysis
-
A novel efficient tandem reaction of hydrazones and α-bromo ketones is reported for the preparation of 1,3,5-trisubstituted pyrazoles by visible light catalysis. In this system, the monosubstituted hydrazones show wonderful reaction activity with alkyl radicals, generated from α-bromo ketones. A radical addition followed by intramolecular cyclization affords the important pyrazole skeleton in good to excellent yields. This efficient strategy under mild conditions with wide group tolerance provides a potential approach to the 1,3,5-trisubstituted pyrazoles.
- Fan, Xiu-Wei,Lei, Tao,Zhou, Chao,Meng, Qing-Yuan,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
-
p. 7127 - 7133
(2016/08/30)
-
- Synthesis, characterization and density functional theory study of low cost hydrazone sensitizers
-
The 2-{4-[2-benzylidenehydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 1), 2-{4-[2-(1- naphthylmethylene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 2) and 2-{4-[2-(9-anthrylmethylene)- hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 3) were synthesized by direct tricyanovinylation of hydrazones. The bathochromic shift in absorption spectra has been observed by increasing the solvent polarity. The FTIR spectra of these new dyes exhibited three important absorption bands. The first band centered near 3260 cm-1 in System 1 while 3208 cm-1 and 3211 cm-1 in System 2 and System 3 for the vNH absorption, respectively. The second band is a sharp absorption band in the region of 2212-2209 cm-1, which was attributed to the cyano group absorption. The third is an absorption band in the region of 1611-1603 cm-1 ascribed for the C=N. Density functional theory (DFT) calculation of relative energies, relative enthalpies and free energies shows that E isomers are the most stable except System 3 in which the most stable is Z isomers. The conformational energy profile shows two maxima near (-90 and 90°) while three local minima observed at (-180, 0 and 180) for N1-N2-C1-C2 torsional angle. The highest occupied molecular orbitals (HOMOs) are localized on the whole molecules while lowest unoccupied molecular orbitals (LUMOs) are distributed on the tricarbonitrile.
- Al-Sehemi, Abdullah G.,Irfan, Ahmad,Asiri, Abdullah M.,Ammar, Yousry Ahmed
-
p. 137 - 148
(2015/01/30)
-
- A novel chemoselective synthesis of 3H-spiro[isobenzofuran-1,3'-pyrazole] derivatives by oxidative cleavage of their corresponding dihydroindeno[1,2-c]pyrazoles
-
Abstract This paper reports a new and simple procedure for the synthesis of 3H-spiro[isobenzofuran-1,3'-pyrazole] derivatives by reacting 1-benzylidene-2-phenylhydrazine derivatives with ninhydrin in acetic acid medium at room temperature followed by oxidative cleavage of their corresponding dihydroindeno[1,2-c]pyrazoles. 1-Benzylidene-2-phenylhydrazine derivatives were prepared via the reaction between phenylhydrazine and benzaldehyde derivatives. Easy procedure, mild reaction conditions, high yields in short reaction times, availability of starting materials, and no formation of by-product are the advantages of this approach.
- Mohammadizadeh, Mohammad Reza,Basti, Fatemeh
-
p. 1171 - 1176
(2015/06/02)
-
- Novel 5-functionalized-pyrazoles: Synthesis, characterization and pharmacological screening
-
In the present study a series of O-substituted pyrazoles 7(a-f) and N-substituted pyrazoles 9(a-f) were synthesized via phase-transfer catalyzed reaction of ethyl 5-(bromomethyl)-1,3-diphenyl-1H-pyrazole-4-carboxylate 5 with various oxygen and nitrogen containing compounds in presence of tetrabutylammonium bromide (TBAB) in THF. The compound 5 was obtained by the efficient bromination with N-bromosuccinimide (NBS) in presence of a catalytic amount of azoiso-bis-butyro nitrile (AIBN) in refluxing CCl4. The synthesized compounds were evaluated for their in vitro antimicrobial and antidiabetic activity and were compared with standard drugs. Among the synthesized compounds, compound 9b emerged as an excellent antimicrobial and antidiabetic agent. Newly synthesized compounds were characterized by analytical and spectral (IR, 1H NMR, 13C NMR and LC-MS) methods.
- Doddaramappa, Shridevi D.,Lokanatha Rai,Srikantamurthy, Ningaiah,Chandra,Chethan, Javarasetty
-
p. 3671 - 3675
(2015/08/11)
-
- Molecular iodine catalysed domino cyclization in aqueous medium: a simple and efficient synthetic route to 1,4-dihydropyridazines
-
A facile, efficient and environmentally friendly approach has been developed for the diverse synthesis of 1,4-dihydropyridazines from (E)-2-benzylidene-1-phenylhydrazine and α,β-unsaturated aldehyde under aqueous condition using molecular iodine as a green and recoverable catalyst. This procedure features low cost and easily available starting materials, an inexpensive and recoverable catalyst, short reaction time, reliable scalability, excellent yield and mild reaction conditions, as well as use of aqueous medium. The scope of this method was thoroughly explored under three different reaction conditions resulting in the generation of a library of title compounds. In view of the various advantages of the present investigation, this methodology gives a convenient and straightforward pathway to construct 1,4-dihydropyridazines in an eco-friendly fashion.
- Siddiqui,Rahila,Rai, Pragati,Sagir, Hozeyfa,Waseem, Malik A.
-
p. 52355 - 52360
(2015/06/25)
-
- Room temperature ionic liquid choline chloride-oxalic acid: A versatile catalyst for acid-catalyzed transformation in organic reactions
-
An efficient and facile synthesis of hydrazones, bis(indolyl)methanes and bis(4-hydroxycoumarin)methanes is facilitated by room temperature ionic liquid choline chloride-oxalic acid (ChCl:Ox). ChCl:Ox (10 mol%) efficiently catalyzes condensation of aldehydes with phenylhydrazine giving corresponding hydrazones in high yield (92-96%) within short reaction time of 3-5 min. Electrophilic cyclization reaction of indole and 4-hydroxy coumarin with aromatic aldehyde was effectively promoted by 30 mol% of ChCl:Ox giving corresponding bis(indolyl)arylmethanes and bis (4-hydroxycoumarin)methanes in good yield at room temperature. Procedure is very simple, solvent free and completely eliminates use of toxic acid catalyst. ChCl:Ox is biodegradable, can be recycled and reused without the loss of efficiency with respect to yield.
- Yadav, Urmiladevi Narad,Shankarling, Ganapati Subray
-
p. 137 - 141
(2014/01/17)
-
- Nano BF3·SiO2: A green heterogeneous solid acid for synthesis of formazan dyes under solvent-free condition
-
A solvent-free, efficient and rapid approach for synthesis of formazan dyes was developed by diazotization of aromatic amines with NaNO2, nano silica-supported boron trifluoride (nano BF3·SiO2), then diazo coupling with aldehyde phenylhydrazones by grinding method at room temperature. This study aimed to overcome the limitations and drawbacks of the previous reported methods such as: low temperature, using corrosive and toxic acids and solvents, using buffer solutions, instability of aryl diazonium salts, modest yields, and long reaction times.
- Bamoniri, Abdolhamid,Mirjalili, Bi Bi Fatemeh,Moshtael-Arani, Naimeh
-
p. 272 - 278
(2014/07/22)
-
- Microwave-assisted synthesis of fulleropyrazolines/fulleroisoxazolines mediated by (diacetoxyiodo)benzene: A rapid and green procedure
-
Microwave as a green, rapid and effective procedure has been applied to the synthesis of fulleropyrazolines/fulleroisoxazolines. The reaction mixtures containing substituted phenylhydrazones/oximes, C60 and PhI(OAc) 2 allowed to achieve products at room temperature in a good yield and short time without any side product.
- Safaei-Ghomi, Javad,Masoomi, Reihaneh
-
p. 2954 - 2960
(2014/01/06)
-
- Comparative experimental and theoretical studies of N-(4-Methylbenzylidene) -N′-(2-carboxyphenyl) hydrazine novel Schiff base
-
In this work, N-(4-Methylbenzylidene)-N′-(2-carboxyphenyl) hydrazine, C15H14N2O2, Schiff base molecule has been synthesized and characterized by elemental analyses, UV-Vis and IR spectroscopy and single crystal X-ray determination. The molecule of the title compound adopt an E configuration about the azomethine CN double bond. The benzene and phenyl rings are planar and the dihedral angle between the planes is 7.2(2)°. The crystal structure is stabilized by intermolecular OHO and intramoleculer NHO hydrogen bonding interactions. X-ray diffraction analyses show that, N-(4-Methylbenzylidene)-N′-(2-carboxyphenyl) hydrazine Schiff base molecule crystallizes in the monoclinic system, P21/c space group, a = 4.392(5) A?, b = 22.340(5) A?, c = 13.528(5) A?, β = 92.882(5)°, V = 1325.7(16) A?3, Z = 4. The conformational analysis of N-(4-Methylbenzylidene)-N′-(2-carboxyphenyl) hydrazine was performed by the density functional theory (DFT) B3LYP method using the 6-311++G(d,p) basis set. Also, theoretical values of FTIR and UV-Vis were performed by the same method. The calculated geometry parameters, IR and UV-Vis results were compared with experimental results.
- Tun?, Tuncay,Tezcan, Habibe,Sa?lam, Semran,Dilek, Nefise
-
p. 490 - 497
(2014/04/17)
-