12 results on '"1,1,1,3,3,3-Hexafluoroisopropanol"'
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2. Electrosynthesis 2.0 in 1,1,1,3,3,3‐Hexafluoroisopropanol/Amine Mixtures.
- Author
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Röckl, Johannes L., Dörr, Maurice, and Waldvogel, Siegfried R.
- Subjects
ELECTROSYNTHESIS ,DERACEMIZATION ,MIXTURES ,NATURAL products ,MOIETIES (Chemistry) ,FUNCTIONAL groups ,FLUOROETHYLENE - Abstract
The intention of this review is to highlight the innovative electrolyte combination of 1,1,1,3,3,3‐hexafluoroisopropanol (HFIP) with tertiary nitrogen bases in electro‐organic synthesis. This easy applicable and promising mixture is not yet well established in electro‐organic synthesis, but expands the various possibilities in the latter. Combinations of fluorinated alcohols with nitrogen bases form highly conductive electrolyte systems, which can be evaporated completely. Consequently, no additional supporting electrolyte is required and work‐up procedures are tremendously simplified. With this electrolyte mixture carbon‐carbon homo‐ and cross‐coupling reactions of arenes and phenols have been established with substrates that have not been previously susceptible to the anodic dehydrogenative coupling reaction. The intermediate installation of highly fluorinated alkoxy moieties can be exploited for subsequent conversions as well as various benzylic functionalization, including asymmetric transformations. These transformations show unique selectivity and functional group tolerance making them highly applicable to the synthesis of sophisticated structural motifs, including natural products. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
3. 1,1,1,3,3,3-Hexafluoroisopropanol and 2,2,2-trifluoroethanol act more effectively on protein in combination than individually: Thermodynamic aspects.
- Author
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Jha, Niki S., Judy, Eva, and Kishore, Nand
- Subjects
- *
PROTEINS , *THERMODYNAMICS , *ALCOHOLS (Chemical class) , *ENTHALPY , *CIRCULAR dichroism - Abstract
2,2,2-Trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) are known to be secondary structure inducers of proteins. In order to determine the efficacy of TFE and HFIP in affecting the conformation of proteins when taken together, as compared to individually, we have studied the thermodynamics of unfolding of bovine serum albumin (BSA) in the presence of these alcohols along with the conformational characterization of the protein. A comparison of change in thermal transition temperature of the protein in the absence and presence of these alcohols in combination and individually shows that the (TFE+HFIP) mixture is a stronger stabilizer of BSA up to a certain molality as compared to addition of their individual effects. The thermodynamics of effects of these alcohols on dithiotheitol reduced BSA were also studied. The enthalpies of interaction of TFE with HFIP in aqueous solution were measured by using isothermal titration calorimetry. The endothermic molar enthalpy of interaction of TFE with HFIP suggests that these alcohols do not strongly associate with each other through polar interactions. This is a possible explanation for their stronger effect on protein stability and conformation in combination rather than individually. The circular dichroism and fluorescence spectroscopic results provide evidence for the enhancement of the secondary structure of the protein by TFE and HFIP along with internalization of tryptophan residues in more hydrophobic environment. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
4. HFIP as a metal-free alternative for cyclization and oxidation reactions
- Author
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Baeza, Alejandro, Universidad de Alicante. Instituto Universitario de Síntesis Orgánica, Llopis, Natalia, Baeza, Alejandro, Universidad de Alicante. Instituto Universitario de Síntesis Orgánica, and Llopis, Natalia
- Abstract
En la presente tesis se desarrolla el empleo de alcoholes fluorados, en concreto, el hexafluoroisopropano, como disolventes para el desarrollo de metodologías alternativas para las reacciones de oxidación y ciclación. De este modo, en el primer capítulo, síntesis de tetrahidrofuradons substituidos mediante la apertura cíclica de epóxidos con alquenos ricos en electrones promovida por HFIP, se ha desarrollado un método directo para la síntesis de tetrahidrofuranos a través de la adición de alquenos ricos en electrones a epóxidos empleando alcoholes fluorados, en particular el 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), como disolventes y promotores de la reacción. El procedimiento descrito da lugar a la obtención de nuevos espiro compuestos basados en tetrahidrofuranos, así como derivados de tetrahidrobenzofuranos en rendimientos moderados y bajo condiciones de reacción suaves siendo, de este modo, una metodología medioambientalmente benigna debido a su economía atómica y la disponibilidad de los reactivos. Por otro lado, en el segundo capítulo, oxidación de arenos ricos en electrones empleando sistemas HFIP-UHP, se ha descrito la oxidación directa de arenos ricos en electrones empleando el aducto de urea-peróxido de hidrógeno (UHP) como fuente oxidante y el 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) como disolvente y promotor de la reacción. Así pues, se obtuvieron una gran variedad de quinonas en rendimientos de moderados a excelentes mediante un proceso de reacción considerado como sostenible, quedando de este modo demostrado que no es necesaria la utilización de metales para dar lugar al proceso oxidativo. Dentro del tercer capítulo, síntesis directa de N,N-formamidas disubstituidas mediante la oxidación de iminas empleando sistemas de HFIP-UHP, se describe la síntesis directa de formamidas N,N-disustituidas mediante la combinación de 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) como disolvente y el aducto de urea-peróxido de hidrógeno (UHP) como fuente oxidante. Se obtu
- Published
- 2022
5. Efficient synthesis of quinazoline derivatives catalyzed by flourinated alcohol.
- Author
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Maleki, Behrooz and Mofrad, Akram
- Subjects
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AROMATIC compound synthesis , *QUINAZOLINE , *AROMATIC aldehydes , *CATALYSTS , *CATALYSIS - Abstract
A facile and efficient protocol is reported for the synthesis of quinazoline derivatives via a one-pot multicomponent reaction of 2-amino-5-chlorobenzophenone, aromatic aldehydes and ammonium acetate using 1,1,1,3,3,3-hexafluoroisopropanol (HFIP). The use of HFIP both as the solvent and catalyst has significant advantages, including avoiding the use of an acidic catalyst and ease of product isolation. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. HFIP as a metal-free alternative for cyclization and oxidation reactions
- Author
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Llopis, Natalia, Baeza, Alejandro, and Universidad de Alicante. Instituto Universitario de Síntesis Orgánica
- Subjects
Alcoholes ,Oxidaciones ,Indoles ,1,1,1,3,3,3-hexafluoroisopropanol ,Formamidas ,Química Sostenible ,Epóxido ,Peróxido de hidrógeno ,Química Orgánica ,Quinolinas ,Tetrahidrofuranos ,Aducto urea-peróxido de hidrógeno ,Alquenos ,Tetrahidroquinolinas ,Iminas ,Compuestos N- heterocíclicos ,Arenos - Abstract
En la presente tesis se desarrolla el empleo de alcoholes fluorados, en concreto, el hexafluoroisopropano, como disolventes para el desarrollo de metodologías alternativas para las reacciones de oxidación y ciclación. De este modo, en el primer capítulo, síntesis de tetrahidrofuradons substituidos mediante la apertura cíclica de epóxidos con alquenos ricos en electrones promovida por HFIP, se ha desarrollado un método directo para la síntesis de tetrahidrofuranos a través de la adición de alquenos ricos en electrones a epóxidos empleando alcoholes fluorados, en particular el 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), como disolventes y promotores de la reacción. El procedimiento descrito da lugar a la obtención de nuevos espiro compuestos basados en tetrahidrofuranos, así como derivados de tetrahidrobenzofuranos en rendimientos moderados y bajo condiciones de reacción suaves siendo, de este modo, una metodología medioambientalmente benigna debido a su economía atómica y la disponibilidad de los reactivos. Por otro lado, en el segundo capítulo, oxidación de arenos ricos en electrones empleando sistemas HFIP-UHP, se ha descrito la oxidación directa de arenos ricos en electrones empleando el aducto de urea-peróxido de hidrógeno (UHP) como fuente oxidante y el 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) como disolvente y promotor de la reacción. Así pues, se obtuvieron una gran variedad de quinonas en rendimientos de moderados a excelentes mediante un proceso de reacción considerado como sostenible, quedando de este modo demostrado que no es necesaria la utilización de metales para dar lugar al proceso oxidativo. Dentro del tercer capítulo, síntesis directa de N,N-formamidas disubstituidas mediante la oxidación de iminas empleando sistemas de HFIP-UHP, se describe la síntesis directa de formamidas N,N-disustituidas mediante la combinación de 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) como disolvente y el aducto de urea-peróxido de hidrógeno (UHP) como fuente oxidante. Se obtuvieron de este modo una gran variedad de formamidas con unos rendimientos de buenos a excelentes bajo unas condiciones suaves de reacción, siendo también posible su síntesis a través de una secuencia de un paso. Este protocolo medioambientalmente benigno fue aplicado para la síntesis a gran escala de la N,N-difenilformamida. En el capítulo 4, ruptura oxidativa de indoles mediante el empleo de UHP o H2O2 en disolventes polares, se ha llevado a cabo la ruptura oxidativa de indoles, conocida como oxidación de Witkop, mediante el empleo de disolventes polares con una fuente oxidativa como el agua oxigenada o el aducto de urea-peróxido de hidrógeno (UHP). En efecto, el uso del HFIP, de entre los disolventes utilizados, fue seleccionado como el más recomendable para la obtención de las 2-cetoacetanilidas con altos rendimientos. Además de los indoles, este protocolo de reacción se amplió para la ruptura de los derivados de pirrol y furanos. Además, se demostró que dicho procedimiento era factible a mayor escala, pudiendo recuperar y reutilizar el disolvente hasta cuatro ciclos, dando lugar a una metodología sostenible. Finalmente, dentro del último capítulo que encontramos en la tesis, deshidrogenación de compuestos N-heterocíclicos empleando H2O2 y mediada por disolventes polares, se expone una deshidrogenación oxidativa alternativa de compuestos N-heterocíclicos mediada por una fuente oxidativa más verde, como es el agua oxigenada, en combinación con disolventes polares como el HFIP o el agua. Aunque se obtuvieron buenos resultados al emplear el agua como disolvente, se lograron alcanzar rendimientos más altos para los derivados heteroaromáticos cuando se utilizó el HFIP debido a la activación electrofílica del H2O2. Junto con la amplia gama de tetrahidroquinolinas seleccionadas, diferentes compuestos N-heterocíclicos como las tetrahidroisoquinolinas o las indolinas, también se llevaron a estudio obteniendo los correspondientes productos con bajos rendimientos. Además de esto, es importante señalar que le metodología descrita fue también implementada en gran escala, reciclando de este modo el disolvente hasta cinco veces con una ligera erosión en la conversión después de cada ciclo. Con ello, se han desarrollado metodologías alternativas donde se reduce el uso de metales como catalizadores o condiciones extremas de reacción, ya bien sea por las elevadas temperaturas o presiones. Por otro lado, se ha propuesto en todos los capítulos un mecanismo de reacción para cada uno de los procedimientos descritos, así como el reciclaje y reutilización de disolvente, o la síntesis a gran escala, demostrándose la aplicabilidad de los procesos y demostrando la sostenibilidad del proceso.
- Published
- 2022
7. 1,1,1,3,3,3-Hexafluoroisopropanol and 2,2,2-trifluoroethanol act more effectively on protein in combination than individually: Thermodynamic aspects
- Author
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Eva Judy, Nand Kishore, and Niki S. Jha
- Subjects
0301 basic medicine ,Circular dichroism ,ALPHA-LACTALBUMIN ,1,1,1,3,3,3-Hexafluoroisopropanol ,Enthalpy ,CYTOCHROME-C ,03 medical and health sciences ,chemistry.chemical_compound ,General Materials Science ,BOVINE SERUM-ALBUMIN ,Physical and Theoretical Chemistry ,Bovine serum albumin ,Protein secondary structure ,Thermal unfolding ,TRIFLUOROETHANOL ,Aqueous solution ,030102 biochemistry & molecular biology ,biology ,2,2,2-Trifluoroethanol ,Tryptophan ,Isothermal titration calorimetry ,MASS-SPECTROMETRY ,RIBONUCLEASE-A ,MOLTEN-GLOBULE STATE ,BETA-LACTOGLOBULIN ,Atomic and Molecular Physics, and Optics ,Crystallography ,030104 developmental biology ,chemistry ,FOLDING INTERMEDIATE ,biology.protein ,WATER MIXTURES - Abstract
2,2,2-Trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) are known to be secondary structure inducers of proteins. In order to determine the efficacy of TFE and HFIP in affecting the conformation of proteins when taken together, as compared to individually, we have studied the thermodynamics of unfolding of bovine serum albumin (BSA) in the presence of these alcohols along with the conformational characterization of the protein. A comparison of change in thermal transition temperature of the protein in the absence and presence of these alcohols in combination and individually shows that the (TFE+ HFIP) mixture is a stronger stabilizer of BSA up to a certain molality as compared to addition of their individual effects. The thermodynamics of effects of these alcohols on dithiotheitol reduced BSA were also studied. The enthalpies of interaction of TFE with HFIP in aqueous solution were measured by using isothermal titration calorimetry. The endothermic molar enthalpy of interaction of TFE with HFIP suggests that these alcohols do not strongly associate with each other through polar interactions. This is a possible explanation for their stronger effect on protein stability and conformation in combination rather than individually. The circular dichroism and fluorescence spectroscopic results provide evidence for the enhancement of the secondary structure of the protein by TFE and HFIP along with internalization of tryptophan residues in more hydrophobic environment. (C) 2018 Elsevier Ltd.
- Published
- 2018
8. Synthesis and biological activity of O-carbamoylated 1,1,1,3,3,3-hexafluoroisopropanols as new specific inhibitors of carboxylesterase.
- Author
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Mukhamadieva, G., Boltneva, N., Galenko, T., Sokolov, V., Epishina, T., and Makhaeva, G.
- Subjects
- *
ACTIVATION (Chemistry) , *CARBOXYLESTERASES , *ENZYME inhibitors , *PROPANOLS , *CARBAMOYL compounds , *ORGANIC synthesis , *CHEMICAL kinetics - Abstract
A series of O-carbamoylated 1,1,1,3,3,3-hexafluoroisopropanols of general formula RNHC(O)OCH(CF), where R = CH, n-CH, tert-CH, cyclo-CH, CH-CH, CH, 4-Cl-CH, 3-Cl-CH, 3,4-Cl-CH, and naphthylen-2-yl were synthesized. The reaction kinetics of the synthesized carbamates with human erythrocyte acetylcholinesterase (EC 3.1.1.7), horse serum butyrylcholinesterase (EC 3.1.1.8), and porcine liver carboxylesterase (EC 3.1.1.1) were studied. It was shown that the synthesized carbamates did not inhibit acetylcholinesterase, inhibited weakly butyrylcholinesterase, and inhibited selectively the activity of carboxylesterase. A new selective irreversible inhibitor of carboxylesterase, 2,2,2-trifluoro-1-trifluoromethylethyl cyclohexylcarbamate, which had low acute toxicity, was obtained. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
9. 1,1,1,3,3,3-Hexafluoroisopropanol as an efficient medium for the room temperature oxidation of styrenes to benzaldehydes.
- Author
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Zhang, Zhuyong, Chen, Weidong, and Luo, Junfei
- Subjects
- *
BENZALDEHYDE , *STYRENE , *STYRENE derivatives , *OXIDATION , *ALDEHYDE derivatives , *FUNCTIONAL groups - Abstract
• Discovered a NHPI-catalyzed oxidation of styrenes to benzaldehyde derivatives. • Practical convenience and highly functional group tolerance. • Mild reaction conditions and low-cost reagents. A room temperature N -hydroxyphthalimide-catalyzed oxidation of styrene derivatives to the corresponding aldehydes has been developed. The use of 1,1,1,3,3,3-hexafluoroisopropanol as the solvent was determined as being key for efficient oxidation. The incorporated oxygen atom originates from molecular dioxygen. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
10. Apparent Molar Heat Capacities and Apparent Molar Volumes of Aqueous 1,1,1,3,3,3-Hexafluoroisopropanol at Different Temperatures
- Author
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Kundu, Agnita and Kishore, Nand
- Published
- 2004
- Full Text
- View/download PDF
11. Apparent molar heat capacities and apparent molar volumes of aqueous 1,1,1,3,3,3-hexafluoroisopropanol at different temperatures
- Author
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Agnita Kundu and Nand Kishore
- Subjects
Molar ,Thermodynamic Properties ,1,1,1,3,3,3-Hexafluoroisopropanol ,Biophysics ,Thermodynamics ,Density ,Biochemistry ,Heat capacity ,Aggregation ,Differential scanning calorimetry ,Molar volume ,Transport-Properties ,Partial Molar Heat Capacity ,Expansion Coefficient ,Cytochrome-C ,Physical and Theoretical Chemistry ,Molecular Biology ,Molality ,Aqueous solution ,Chemistry ,Water ,Proteins ,Partial molar property ,Partial Molar Volume ,Volume (thermodynamics) ,Hexafluoroisopropanol ,Alcohols ,Peptides ,State - Abstract
Specific heats and apparent molar heat capacities of aqueous 1,1,1,3,3,3-hexafluoroisoproanol (HFIP) have been determined at temperatures from 20.0 to 45.0degreesC using micro differential scanning calorimetry in the molality range of 0.06741 to 1.24053 mol-kg(-1). Densities and apparent molar volumes have also been determined for aqueous HFIP at temperatures from 10.3 to 30.0degreesC using digital densimetry in the molality range of 0.04009 to 0.67427 mol-kg(-1). The results of these measurements have been used to calculate the following partial molar quantities and temperature derivatives for aqueous HFIP as a function of temperature: C(p,2,m)degrees, (partial derivativeC(p,2,m)degrees/partial derivativeT)(p), (partial derivative(2)C(p,2,m)degrees/partial derivativeT(2))(p), V(2,m)degrees and (partial derivativeV(2,m)degrees/partial derivativeT)(p). The contribution of the -F atom to the partial molar heat capacity and volume has been calculated. The results have been explained in terms of structural changes in water in aqueous HFIP solution. The results obtained in this work contain essential information needed for the development of an equation of state for this system, when used in combination with other thermodynamic properties of aqueous HFIP.
- Published
- 2004
12. Forced degradation and impurity profiling: recent trends in analytical perspectives.
- Author
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Jain D and Basniwal PK
- Subjects
- Animals, Chemistry, Pharmaceutical methods, Chromatography, High Pressure Liquid methods, Chromatography, High Pressure Liquid trends, Humans, Chemistry, Pharmaceutical trends, Drug Contamination, Pharmaceutical Preparations analysis
- Abstract
This review describes an epigrammatic impression of the recent trends in analytical perspectives of degradation and impurities profiling of pharmaceuticals including active pharmaceutical ingredient (API) as well as drug products during 2008-2012. These recent trends in forced degradation and impurity profiling were discussed on the head of year of publication; columns, matrix (API and dosage forms) and type of elution in chromatography (isocratic and gradient); therapeutic categories of the drug which were used for analysis. It focuses distinctly on comprehensive update of various analytical methods including hyphenated techniques for the identification and quantification of thresholds of impurities and degradants in different pharmaceutical matrices., (© 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
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