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Galindres DM, Ribeiro AC, Esteso MA, Vargas EF. Standard molar properties of ionic resorcinarenes in water and dimethysulfoxide. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
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2
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Pineda-Castañeda H, Rivera-Monroy ZJ, Maldonado M. Copper(I)-Catalyzed Alkyne-Azide Cycloaddition (CuAAC) "Click" Reaction: A Powerful Tool for Functionalizing Polyhydroxylated Platforms. ACS OMEGA 2023; 8:3650-3666. [PMID: 36743057 PMCID: PMC9893463 DOI: 10.1021/acsomega.2c06269] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/23/2022] [Indexed: 05/13/2023]
Abstract
Click chemistry is currently one of the most used tools for the generation of complex organic molecules. The advantages of using click chemistry in organic synthesis are remarkable; in many cases, the reactions occur under mild conditions and are free of solvents, with high yields and short reaction times. This makes it an extraordinarily effective and viable alternative for obtaining complex/conjugated molecules. In this review, the use of click chemistry CuAAC is especially emphasized for polyhydroxylated platforms such as resorcinarenes or calixarenes, focusing mainly on aspects of synthesis, specifically conditions, reagents, and methodologies.
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Affiliation(s)
- Héctor
Manuel Pineda-Castañeda
- Chemistry
Department, Universidad Nacional de Colombia,
Bogotá, Carrera 45 No 26-85, Building 451, office 409, Bogotá 11321, Colombia
| | - Zuly Jenny Rivera-Monroy
- Chemistry
Department, Universidad Nacional de Colombia,
Bogotá, Carrera 45 No 26-85, Building 451, office 409, Bogotá 11321, Colombia
| | - Mauricio Maldonado
- Chemistry
Department, Universidad Nacional de Colombia,
Bogotá, Carrera 45 No 26-85, Building 451, office 409, Bogotá 11321, Colombia
- Email
for M.M.:
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3
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Casas-Hinestroza JL, Pérez-Redondo A, Maldonado M. Inclusion complexation between neurotransmitters with polyacetylated calix[4]pyrogallolarenes: 1H-NMR and crystallographic analysis. RESEARCH ON CHEMICAL INTERMEDIATES 2022. [DOI: 10.1007/s11164-022-04735-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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4
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Abstract
Due to the diseases that people face today, scientists dedicate a part of their research to the synthesis, characterization, and study of functional compounds for controlled drug delivery. On the one hand, resorcinarenes are macrocycles obtained by condensation reactions of resorcinol and aldehyde. They include an upper and a lower rim functioning with different groups that confer solubility to the macrocycle and favor interactions with other compounds, therefore the hydroxyl groups on the upper rim improve the formation of hydrogen bonds. Additionally, resorcinarenes feature a cavity studied for forming host-guest complexes. SBA-15, on the other hand, is a mesoporous silica characterized by ordered pores in its structure and a large surface area. As a result of its properties, it has been used for several purposes, including absorbents, drug delivery, catalysis, and environmental processes. This review shows the recent advances in synthesis methods, characterization, micelle formation, interaction with other compounds, and host-guest procedures, as well as techniques for evaluating toxicity, drug retention, and their preliminary uses in pharmacology for macrocycles, such as resorcin[4]arenes and SBA-15.
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Qu G, Bilal R, Xin M, Lv Z, Jin G, Tan Y, Yao Z, Cai H. Phase transition-induced changes in the Raman properties of DMSO/benzene binary systems. Phys Chem Chem Phys 2021; 23:9211-9217. [PMID: 33885110 DOI: 10.1039/d1cp00627d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The Raman spectra of dimethylsulfoxide (DMSO)/benzene binary mixtures were studied by decreasing the temperature from 333 K to 263 K with the aim to reveal the molecular interaction properties during phase transition. The intensity of the Raman band for benzene at 992 cm-1 showed an increasing trend in the liquid and solid phases, while it exhibited a highly decreasing trend during the liquid-solid phase transition. The potential energy was calculated to study the effect of intermolecular interaction distance between DMSO and benzene on Raman intensity. The observations indicated that the blueshift of the low-frequency bands of DMSO was significantly different from the redshift of its high-frequency bands. The hydrogen bond generated between DMSO and benzene was well formed in the binary systems. This interaction inducing an enhanced hydrogen bond between the binary systems and attenuated C-H bonds led to opposite Raman shift variations with decreasing temperature. The Raman bands of DMSO at 1425 cm-1, 2899 cm-1, and 2992 cm-1 each split into two peaks after phase transition. The splitting of the Raman bands of DMSO at 1417 cm-1, 2895 cm-1, and 2982 cm-1 cropped up as the temperature dropped to the transformation point of 288 K. This is attributed to the phase transition-induced latent def.(C7) atomic vibrations corresponding to the individual methyl groups of DMSO. The implications of these analyses are expected to be helpful to understand the effect of phase transition on the Raman properties of binary solutions.
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Affiliation(s)
- Guannan Qu
- School of Science, Changchun University of Science and Technology, Changchun, 130022, China.
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Maldonado M, Sanabria E, Velasquez-Silva A, Casas-Hinestroza JL, Esteso MA. Comparative study of the volumetric properties of three regioisomers of diazoted C-tetra(propyl)resorcin[4]arene in DMSO at various temperatures. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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7
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Castillo-Aguirre A, Esteso MA, Maldonado M. Resorcin[4]arenes: Generalities and Their Role in the Modification and Detection of Amino Acids. CURR ORG CHEM 2020. [DOI: 10.2174/1385272824999200510232141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The characteristics and properties that enable resorcin[4]arenes to self-assemble
in order to form derivatives with amino acids with a high potential for application in various
fields are reviewed. In particular, resorcin[4]arene synthesis, their characteristics, the
variety in the size of cavity, their functional groups, and their applications associated with
molecular interactions are described in this study. Also, the types of amino acids that can
be recognized by resorcin[4]arenes, their interactions, the techniques that allow the determination
of the association constants, and the evaluation of the stoichiometry of the complex
formed, are reviewed.
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Affiliation(s)
- Alver Castillo-Aguirre
- Department of Chemistry, Faculty of Science, National University of Colombia-Bogota Headquarters, 30 No. 45-03 Carrera, Colombia
| | - Miguel Angel Esteso
- Universidad Catolica Santa Teresa de Jesus de Avila. Calle los Canteros s/n. 05005 Avila, Spain
| | - Mauricio Maldonado
- Department of Chemistry, Faculty of Science, National University of Colombia-Bogota Headquarters, 30 No. 45-03 Carrera, Colombia
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Casas-Hinestroza JL, Cifuentes A, Ibáñez E, Maldonado M. Effect of the formation of capsules of tetra(propyl) pyrogallol[4]arene on the host-guest interaction with neurotransmitters. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Castillo-Aguirre AA, Pérez-Redondo A, Maldonado M. Influence of the hydrogen bond on the iteroselective O-alkylation of calix[4]resorcinarenes. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127402] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Velásquez-Silva A, Forero RS, Sanabria E, Pérez-Redondo A, Maldonado M. Host-guest inclusion systems of tetra(alkyl)resorcin [4]arenes with choline in DMSO: Dynamic NMR studies and X-ray structural characterization of the 1:1 inclusion complex. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.07.093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Castillo-Aguirre A, Maldonado M. Preparation of Methacrylate-based Polymers Modified with Chiral Resorcinarenes and Their Evaluation as Sorbents in Norepinephrine Microextraction. Polymers (Basel) 2019; 11:E1428. [PMID: 31480387 PMCID: PMC6780700 DOI: 10.3390/polym11091428] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 08/19/2019] [Accepted: 08/26/2019] [Indexed: 11/17/2022] Open
Abstract
Aminomethylation reactions between chiral amino compounds (S)-(-)-1-phenylethylamine and l-proline with tetranonylresorcinarene and tetra-(4-hydroxyphenyl)resorcinarene in presence of formaldehyde were studied. The reaction between l-proline and resorcinarenes generated regioselectively chiral tetra-Mannich bases, due to the molecular incorporation of the fragment of the chiral amino acid. On the other hand, tetranonylresorcinarene and (S)-(-)-1-phenylethylamine formed regio- and diasteroselectively chiral tetrabenzoxazines, both by chiral auxiliary functionalization and by the transformation of the molecular structure that confers inherent chirality. The products obtained were characterized using IR, 1H-NMR, 13C-NMR, COSY, HMQC, and HMBC techniques. The reaction of (S)-(-)-1-phenylethylamine with tetra-(4-hydroxyphenyl)resorcinarene did not proceed under the experimental conditions. Once the chiral aminomethylated tetra-(4-hydroxyphenyl)resorcinarene was obtained, the chemical modification of poly(GMA-co-EDMA) was studied, and the results showed an efficient incorporation of the aminomethylated compound. For the physical modification, chiral aminomethylated tetranonylresorcinarenes were employed, finding that the incorporation of modified resorcinarenes occurs, but with less efficiency than that observed using chemical modification. The modified polymers were characterized via FT-IR, scanning electron microscopy imaging, and elemental analysis. Finally, polymers modified with chiral resorcinarenes were used as sorbents in norepinephrine microextraction; for practical purposes, artificial urine was prepared and used. To perform the microextraction, the decision was made to use the modern rotating-disk sorptive extraction technique (RDSE), because of its analytical attributes as a green, or eco-friendly, technique. According to the results, the method preliminarily validated for the determination of norepinephrine in artificial urine shows that the modified polymer with chiral derivative of tetra-(4-hydroxyphenyl)resorcinarene worked effectively as a new sorbent phase for the quantitative microextraction of norepinephrine, exhibiting high stability and homogeneity of composition and structure within the working range.
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Affiliation(s)
- Alver Castillo-Aguirre
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, 30 No. 45, Carrera 03, Colombia
| | - Mauricio Maldonado
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, 30 No. 45, Carrera 03, Colombia.
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Velásquez-Silva BA, Castillo-Aguirre A, Rivera-Monroy ZJ, Maldonado M. Aminomethylated Calix[4]resorcinarenes as Modifying Agents for Glycidyl Methacrylate (GMA) Rigid Copolymers Surface. Polymers (Basel) 2019; 11:polym11071147. [PMID: 31277429 PMCID: PMC6680909 DOI: 10.3390/polym11071147] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 06/28/2019] [Accepted: 07/02/2019] [Indexed: 01/16/2023] Open
Abstract
Functionalization of tetrapropylcalix[4]resorcinarene, tetrapentylcalix[4]resorcinarene, tetranonylcalix[4]resorcinarene, and tetra-(4-hydroxyphenyl)calix[4]resorcinarene by means of aminomethylation reactions with the amino acids β-alanine and l-proline in the presence of aqueous formaldehyde was carried out. When β-alanine was used, the reaction products were tetrabenzoxazines. The reaction with tetra-(4-hydroxyphenyl)calix[4]resorcinarene did not proceed under the experimental conditions; therefore, l-proline was used, and the corresponding tetra-Mannich base was regio- and diasteroselectively formed. The products were characterized via FT-IR, 1H NMR, 13C NMR, and elemental analysis. With these aminomethylated-calix[4]resorcinarenes, the chemical surface modification of the copolymers poly(GMA-co-EDMA) and poly(BMA-co-EDMA-co-MMA) in a basic medium was studied. The results were quite satisfactory, obtaining the corresponding copolymers functionalized by nucleophilic substitution reaction and ring-opening between the carboxyl group of the upper rim of aliphatic calix[4]resorcinarenes and the hydroxyl group of the lower rim in the aromatic calix[4]resorcinarene and the epoxy group of the glycidyl methacrylate residue of each copolymer. The modified copolymers were characterized via FT-IR, scanning electron microscopy imaging, and elemental analysis. Finally, the modified copolymer surfaces exhibited interaction with peptides, showing their potential application in chromatographic separation techniques such as high-performance liquid chromatography.
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Affiliation(s)
- Betty Astrid Velásquez-Silva
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Carrera 30 No. 45-03, 7122 Carrera, Colombia
| | - Alver Castillo-Aguirre
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Carrera 30 No. 45-03, 7122 Carrera, Colombia
| | - Zuly Jenny Rivera-Monroy
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Carrera 30 No. 45-03, 7122 Carrera, Colombia
| | - Mauricio Maldonado
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Carrera 30 No. 45-03, 7122 Carrera, Colombia.
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13
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Castillo-Aguirre AA, Rivera Monroy ZJ, Maldonado M. Analysis by RP-HPLC and Purification by RP-SPE of the C-Tetra( p-hydroxyphenyl)resorcinolarene Crown and Chair Stereoisomers. JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY 2019; 2019:2051282. [PMID: 31143485 PMCID: PMC6501146 DOI: 10.1155/2019/2051282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/10/2019] [Accepted: 03/27/2019] [Indexed: 05/27/2023]
Abstract
A method for the separation of stereoisomer mixture of the octol C-tetra(p-hydroxyphenyl)calix[4]resorcinarene that was obtained by an acid cyclocondensation reaction between resorcinol and benzaldehyde is reported in this paper. A crude product from octol formation reaction was analyzed by reverse-phase high-performance liquid chromatography (RP-HPLC), and two well-resolved signals corresponding to the crown and chair isomers were found. A reverse phase in solid-phase extraction (RP-SPE) protocol allowed the separation of the two stereoisomers with high purity of each isomer. Finally, the crude and purified stereoisomers were characterized by using FT-IR, 1H-NMR, and 13C-NMR techniques, confirming the chemical identity of the two isomers and the efficiency in the separation process.
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Affiliation(s)
- Alver A. Castillo-Aguirre
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Bogota 11001, Colombia
| | - Zuly Jenny Rivera Monroy
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Bogota 11001, Colombia
| | - Mauricio Maldonado
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Bogota 11001, Colombia
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Calixarenes: Generalities and Their Role in Improving the Solubility, Biocompatibility, Stability, Bioavailability, Detection, and Transport of Biomolecules. Biomolecules 2019; 9:biom9030090. [PMID: 30841659 PMCID: PMC6468619 DOI: 10.3390/biom9030090] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 02/24/2019] [Accepted: 02/28/2019] [Indexed: 12/11/2022] Open
Abstract
The properties and characteristics of calix[n]arenes are described, as well as their capacity to form amphiphilic assemblies by means of the design of synthetic macrocycles with a hydrophilic head and a hydrophobic tail. Their interaction with various substances of interest in pharmacy, engineering, and medicine is also described. In particular, the role of the calix[n]arenes in the detection of dopamine, the design of vesicles and liposomes employed in the manufacture of systems of controlled release drugs used in the treatment of cancer, and their role in improving the solubility of testosterone and anthelmintic drugs and the biocompatibility of biomaterials useful for the manufacture of synthetic organs is emphasized. The versatility of these macrocycles, able to vary in size, shape, functional groups, and hydrophobicity and to recognize various biomolecules and molecules with biological activity without causing cytotoxicity is highlighted.
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Abstract
This article is based on a review of the literature and our own experience with toxicological molecules. We explain the nature of calix[n]arenes and as their recognized properties are used to detect compounds of toxicological interest, mainly the most important pesticide families such as organophosphorated, organochlorine compounds, pyrethroid insecticides, carbamate fungicides, and herbicides, using different techniques. In addition, we show the role of the macrocycle and its interactions, and the advantage of using this type of compound for improving conventional techniques, where the phenomenon of recognition is very important, such as chromatography, solid-phased extraction, and the development of specific sensors, among others and Even we also show the use of this macrocycle for detoxication procedures in vivo. In this way, we display as the multiple possibilities of functionalization of the calix[n]arenes makes these versatile molecules in the phenomena of specific recognition. Finally, This review highlights the main analytical methods reported in the literature for determination of plaguicides by host-guest interaction with calixarenes. In this way, among the available analytical tools, chromatographic, and electrochemical-based methods are the most used techniques for the detection and to quantify plaguicides using calixarenes.
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Affiliation(s)
- Edilma Sanabria Español
- Grupo GICRIM, Programa de Investigación Criminal , Universidad Manuela Beltrán , Bogotá , Colombia
| | - Mauricio Maldonado
- Departamento de Química, Facultad de Ciencias , Universidad Nacional de Colombia , Bogotá , Colombia
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16
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Measurement and relationships of density and viscosity of 1,2‑propylene glycol + dimethyl sulfoxide mixtures and spectral insight. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.08.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Casas-Hinestroza JL, Maldonado M. Conformational Aspects of the O-acetylation of C-tetra(phenyl)calixpyrogallol[4]arene. Molecules 2018; 23:molecules23051225. [PMID: 29783780 PMCID: PMC6100403 DOI: 10.3390/molecules23051225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 05/15/2018] [Accepted: 05/17/2018] [Indexed: 11/16/2022] Open
Abstract
Reaction between pyrogallol and benzaldehyde results in a conformational mixture of C-tetra(phenyl)pyrogallol[4]arene (crown and chair). The conformer mixture was separated using crystallization procedures and the structures were determined using FTIR, 1H-NMR, and 13C-NMR. O-acetylation of C-tetra(phenyl)pyrogallol[4]arene (chair) with acetic anhydride, in pyridine results in the formation of dodecaacetyl-tetra(phenyl)pyrogallol[4]arene. The structure was determined using 1H-NMR and 13C-NMR finding that the product maintains the conformation of the starting conformer. On the other hand, the O-acetylation reaction of C-tetra(phenyl)pirogallol[4]arene (crown) under same conditions proceeded efficiently, and its structure was determined using 1H-NMR and 13C-NMR. Dynamic 1H-NMR of acetylated pyrogallolarene was studied by means of variable temperature in DMSO-d6 solution, and it revealed that two conformers are formed in the solution. Boat conformations for acetylated pyrogallolarene showed a slow interconversion at room temperature.
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Affiliation(s)
- José Luis Casas-Hinestroza
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-sede Bogotá, Carrera 30 # 45-03, Bogotá 111321, Columbia.
| | - Mauricio Maldonado
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-sede Bogotá, Carrera 30 # 45-03, Bogotá 111321, Columbia.
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Sanabria E, Esteso MÁ, Vargas E, Maldonado M. Experimental comparative study of solvent effects on the structure of two sulfonated resorcinarenes. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.01.111] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Selective O-Alkylation of the Crown Conformer of Tetra(4-hydroxyphenyl)calix[4]resorcinarene to the Corresponding Tetraalkyl Ether. Molecules 2017; 22:molecules22101660. [PMID: 28976918 PMCID: PMC6151838 DOI: 10.3390/molecules22101660] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 09/29/2017] [Accepted: 09/30/2017] [Indexed: 11/17/2022] Open
Abstract
Reactions of glycidyl methacrylate with the crown and chair conformers of tetra(4-hydroxyphenyl)calix[4]resorcinarene were studied. The reactions were done over epoxide groups present in the ester, which can easily undergo an opening reaction with hydroxyl groups in the macrocyclic system. Initially, epoxidation reactions were carried out with pure conformers, and it was observed that the reaction between tetra(4-hydroxyphenyl)calix[4]resorcinarene fixed in the chair conformation does not occur, while for the molecule fixed in the crown conformation only one tetraalkylated derivative was obtained. The obtained product was characterized using IR, ¹H-NMR, 13C-NMR, COSY, HMQC and HMBC techniques. An exhaustive NMR study showed that the reaction is selective at the hydroxyl groups in the lower rim, without affecting the hydroxyl groups in the upper rim. In addition, the RP-HPLC analysis of the epoxidation reaction mixture, using both crown and chair conformers, showed that only the crown conformer reacted under tested conditions. Finally, a comparative study of the reactivity of tetranonylcalix[4]resorcinarene with glycidyl methacrylate showed that the reaction does not take place. Instead, the formation of the tetranonylcalix[4]resorcinarene tetrasodium salt was observed, which confirms that the hydroxyl groups in the upper rim are unreactive under these conditions.
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