Discovery of neat silica gel as a catalyst: an example of S → O acetyl migration reaction

Yu Jin; Jiachen Li; Li Peng; Chao Gao

doi:10.1039/c5cc05396j

A Sustainable Improvement of ω-Bromoalkylphosphonates Synthesis to Access Novel KuQuinones

Organics ◽

10.3390/org2020010 ◽

2021 ◽

Vol 2 (2) ◽

pp. 107-117

Author(s):

Mattia Forchetta ◽

Valeria Conte ◽

Giulia Fiorani ◽

Pierluca Galloni ◽

Federica Sabuzi

Keyword(s):

Metal Oxides ◽

Phosphonic Acid ◽

Organic Molecules ◽

Building Blocks ◽

Reaction Conditions ◽

Phosphonic Acids ◽

Sustainable Improvement ◽

Phosphonate Esters ◽

First Time ◽

Complex Organic

Owing to the attractiveness of organic phosphonic acids and esters in the pharmacological field and in the functionalization of conductive metal-oxides, the research of effective synthetic protocols is pivotal. Among the others, ω-bromoalkylphosphonates are gaining particular attention because they are useful building blocks for the tailored functionalization of complex organic molecules. Hence, in this work, the optimization of Michaelis–Arbuzov reaction conditions for ω-bromoalkylphosphonates has been performed, to improve process sustainability while maintaining good yields. Synthesized ω-bromoalkylphosphonates have been successfully adopted for the synthesis of new KuQuinone phosphonate esters and, by hydrolysis, phosphonic acid KuQuinone derivatives have been obtained for the first time. Considering the high affinity with metal-oxides, KuQuinones bearing phosphonic acid terminal groups are promising candidates for biomedical and photo(electro)chemical applications.

Sulfonyl Radical Triggered Selective Iodosulfonylation and Bicycli-zations of 1,6-Dienes

Chemical Communications ◽

10.1039/d1cc03252f ◽

2021 ◽

Author(s):

Shi-Ping Wu ◽

Dong-Kai Wang ◽

Qing-Qing Kang ◽

Guo-Ping Ge ◽

Hongxing Zheng ◽

...

Keyword(s):

Functional Group ◽

High Selectivity ◽

Reaction Conditions ◽

First Time

A novel sulfonyl radical triggered selective iodosulfonylation and bicyclizations of 1,6-dienes has been described for the first time. High selectivity and efficiency, mild reaction conditions, excellent functional group compatibility, and...

Extraction and Mass Spectrometric Characterization of Terpenes Recovered from Olive Leaves Using a New Adsorbent-Assisted Supercritical CO2 Process

Foods ◽

10.3390/foods10061301 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1301

Author(s):

Zully J. Suárez Montenegro ◽

Gerardo Álvarez-Rivera ◽

Jose A. Mendiola ◽

Elena Ibáñez ◽

Alejandro Cifuentes

Keyword(s):

Aluminum Oxide ◽

Silica Gel ◽

Supercritical Co2 ◽

Olive Leaves ◽

Fractionation Process ◽

Selective Enrichment ◽

Adsorption Desorption ◽

First Time ◽

By Products

This work reports the use of GC-QTOF-MS to obtain a deep characterization of terpenoid compounds recovered from olive leaves, which is one of the largest by-products generated by the olive oil industry. This work includes an innovative supercritical CO2 fractionation process based on the online coupling of supercritical fluid extraction (SFE) and dynamic adsorption/desorption for the selective enrichment of terpenoids in the different olive leaves extracts. The selectivity of different commercial adsorbents such as silica gel, zeolite, and aluminum oxide was evaluated toward the different terpene families present in olive leaves. Operating at 30 MPa and 60 °C, an adsorbent-assisted fractionation was carried out every 20 min for a total time of 120 min. For the first time, GC-QTOF-MS allowed the identification of 40 terpenoids in olive leaves. The GC-QTOF-MS results indicate that silica gel is a suitable adsorbent to partially retain polyunsaturated C10 and C15 terpenes. In addition, aluminum oxide increases C20 recoveries, whereas crystalline zeolites favor C30 terpenes recoveries. The different healthy properties that have been described for terpenoids makes the current SFE-GC-QTOF-MS process especially interesting and suitable for their revalorization.

Characterization of the inositol 1,4,5-trisphosphate-induced calcium release from permeabilized endocrine cells and its inhibition by decavanadate and p-hydroxymercuribenzoate

Biochemical Journal ◽

10.1042/bj2620083 ◽

1989 ◽

Vol 262 (1) ◽

pp. 83-89 ◽

Cited By ~ 48

Author(s):

K J Föhr ◽

J Scott ◽

G Ahnert-Hilger ◽

M Gratzl

Keyword(s):

Endocrine Cells ◽

Calcium Release ◽

Cell Types ◽

Inhibitory Effect ◽

Maximal Effect ◽

Thiol Compounds ◽

Inositol 1,4,5 Trisphosphate ◽

Dependent Inhibition ◽

Pheochromocytoma Pc12 ◽

First Time

The inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ compartment of endocrine cells was studied with alpha-toxin- and digitonin-permeabilized rat insulinoma (RINA2) and rat pheochromocytoma (PC12) cells. The Ca2+ uptake was ATP-dependent, and submicromolar concentrations of IP3 specifically released the stored Ca2+. Half-maximal Ca2+ release was observed with 0.25-0.5 mumol of IP3/l, and the amount of Ca2+ released due to IP3 could be enhanced by additional loading of the Ca2+ compartment. Consecutive additions of the same concentration of IP3 for 1-2 h always released the same amount of Ca2+ without desensitization, providing an ideal basis to further characterize the IP3-induced Ca2+ release. Here we describe for the first time a reversible inhibitory effect of decavanadate on the IP3-induced Ca2+ release. Among the vanadium species tested (decavanadate, oligovanadate and monovanadate), only decavanadate was inhibitory, with a half-maximal effect at 5 mumol/l in both cell types. The effect of decavanadate could be overcome by increasing the amount of sequestered Ca2+ or added IP3. Decavanadate did not affect the ATP-driven Ca2+ uptake but oligovanadate was inhibitory on Ca2+ uptake. p-Hydroxymercuribenzoate (pHMB) at concentrations between 10 and 30 mumol/l also inhibited the Ca2+ release due to IP3. Thiol compounds such as dithiothreitol (DTT; 1 mmol/l) added before pHMB removed all its inhibitory effect on the IP3-induced Ca2+ release, whereas the inhibition caused by decavanadate was unaffected by DTT. Thus, the decavanadate-dependent inhibition functions by a distinctly different mechanism than pHMB and could serve as a specific tool to analyse various aspects of the IP3-induced Ca2+ release within endocrine cells.

Effects of reaction conditions on hydrogen production and carbon nanofiber properties generated by methane decomposition in a fixed bed reactor using a NiCuAl catalyst

Journal of Power Sources ◽

10.1016/j.jpowsour.2008.11.096 ◽

2009 ◽

Vol 192 (1) ◽

pp. 35-42 ◽

Cited By ~ 43

Author(s):

I. Suelves ◽

J.L. Pinilla ◽

M.J. Lázaro ◽

R. Moliner ◽

J.M. Palacios

Keyword(s):

Hydrogen Production ◽

Carbon Nanofiber ◽

Fixed Bed ◽

Methane Decomposition ◽

Fixed Bed Reactor ◽

Reaction Conditions

Efficient and Reusable Silica Gel Supported Metal Ionic Liquid Catalysts for Palmitic Acid Esterification to Biodiesel

Journal of the chemical society of pakistan ◽

10.52568/000014 ◽

2021 ◽

Vol 43 (1) ◽

pp. 1-1

Author(s):

Guo Yingwei Guo Yingwei ◽

Chen Xuedan Chen Xuedan ◽

Yan Shiting Yan Shiting ◽

Zhang Zhengliang Zhang Zhengliang ◽

Chen Yuqin Chen Yuqin ◽

...

Keyword(s):

Ionic Liquid ◽

Palmitic Acid ◽

Silica Gel ◽

High Surface ◽

High Surface Area ◽

Kinetic Studies ◽

Catalytic Performance ◽

Reaction Conditions ◽

Acid Esterification ◽

Supported Metal

A series of silica gel (SG) supported metal ionic liquid catalysts (x[Bmim]Cl-CrCl3/SG) were synthesized and exploited for the esterification of palmitic acid (PA) with methanol (ML) to produce biodiesel efficiently. The 10%[Bmim]Cl-CrCl3/SG catalyst with high surface area and desirable acidity exhibited the best catalytic performance and reusability after six consecutive running cycles. Based on the response surface analysis, the optimal reaction conditions were obtained as follows: methanol/acid mole ratio = 11:1 mol/mol, catalyst amount = 5.3 wt%, reaction time = 65 min, as well as reaction temperature = 373 K, reaching to a biodiesel yield of 96.1%. Further kinetic studies demonstrated that the esterification of PA with ML obeyed 1.41 order kinetics for acid concentration with the activation energy of 16.88 kJ/mol

New opportunities in the stereoselective dearomatization of indoles

Pure and Applied Chemistry ◽

10.1515/pac-2016-0101 ◽

2016 ◽

Vol 88 (3) ◽

pp. 207-214 ◽

Cited By ~ 23

Author(s):

Elisabetta Manoni ◽

Assunta De Nisi ◽

Marco Bandini

Keyword(s):

Acid Catalysis ◽

Bronsted Acid ◽

Brønsted Acid ◽

Reaction Conditions ◽

Brönsted Acid ◽

High Yields ◽

First Time ◽

Tailored Design ◽

Bronsted Acid Catalysis

AbstractThe regio- and stereoselective dearomatization of indoles is realized for the first time by combining readily available indolyl precursors and electron-rich allenes, namely allenamides and aryloxyallenes. Inter- as well as intramolecular condensations were realized under gold and Brønsted acid catalysis providing a range of densely functionalized indoline and indolenine cores in high yields and excellent stereochemical outcome. Chemodivergent reaction profiles (Micheal-type addition vs. [2+2]-cycloaddition) were realized by a tailored design of both reaction conditions and functionalization of the reaction partners.

SYNTHESIS OF AN AZIDE–THIOL LINKER FOR HETEROGENEOUS POLYMER FUNCTIONALIZATION VIA THE “CLICK” REACTION

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/55/1b/12103 ◽

2018 ◽

Vol 55 (1B) ◽

pp. 152

Author(s):

Thuy Thu Truong

Keyword(s):

Nuclear Magnetic Resonance ◽

Click Reaction ◽

Proton Nuclear Magnetic Resonance ◽

Reaction Yield ◽

Reaction Conditions ◽

Click Reactions ◽

Heterogeneous Polymer ◽

Ft Ir ◽

First Time ◽

Layer Chromatography

In this study, the synthesis of a telechelic linker bearing both azide and thiol functional groups was described. The reaction conditions were investigated to optimize the reaction yield. The product was analyzed using thin layer chromatography (TLC) and proton nuclear magnetic resonance (1H NMR). The employment of the obtained azide–thiol linker in heterogeneous polymer “click” functionalization was demonstrated for the first time, which was monitored by an online FT–IR method. The obtained telechelic azide–thiol linker is envisioned to be useful chemical tools to link macromolecular chains via orthogonal click reactions.

CHEMICAL CONSTITUENTS AND BIOACTIVITY OF Codium amplivesiculatum SETCHELL N. L.GARDNER (CHLOROPHYTA; BRYOPSIDALES)

CICIMAR Oceánides ◽

10.37543/oceanides.v28i2.124 ◽

2013 ◽

Vol 28 (2) ◽

pp. 1

Author(s):

A. Marín -Álvarez ◽

J. I. Murrillo -Álvarez ◽

M. Muñoz -Ochoa ◽

G. M. Molina -Salinas

Keyword(s):

Staphylococcus Aureus ◽

Silica Gel ◽

Vibrio Parahaemolyticus ◽

Marine Alga ◽

Chemical Constituents ◽

Ethanol Extract ◽

Solvent Mixtures ◽

Bioactive Substances ◽

First Time ◽

Tuberculosis Activity

In search of bioactive substances from Mexican marine organisms, crude ethanol-extract from the marine alga Codium amplivesiculatum was fractionated in chromatographic columns of silica gel at 60 Å (230-400 mesh) using solvent mixtures of increasing polarity. All the fractions were submitted to antibacterial assays. The major metabolite from an anti-tuberculosis fraction (MIC = 100 μg mL–1) was purified and identified as 1-octodecanol (1). The anti-tuberculosis activity was attributed to 1 with bases in previous reports. In addition, clerosterol (2) was obtained by crystallization from an active fraction against Staphylococcus aureus and Vibrio parahaemolyticus (MIC = 125 and 250 μg mL–1, respectively). Both structures were established by interpretation and comparison of infrared and 1H NMR spectroscopic data. In contrast with other studies, 2 showed a non-significant cytotoxicity against the cell line PC-3 (% GI = 21.05 ± 0.3 at 50 μg mL–1). To our knowledge, these metabolites are reported for the first time from C. amplivesiculatum, and this is one of very rare reports of saturated long-chain alcohols isolated from chlorophytes. Constituyentes químicos y bioactividad de Codium amplivesiculatum Con el propósito de descubrir sustancias bioactivas a partir de organismos marinos encontrados en México, se fraccionó el extracto crudo etanólico de Codium amplivesiculatum en columnas cromatográficas de sílica gel 60 Å (230-400 de malla) utilizando mezclas de solventes de polaridad creciente. Todas las fracciones se sometieron a ensayos antibacterianos. El principal metabolito de la fracción activa antituberculosis (MIC = 100 μg mL-1), fue purificado e identificado como 1-octodecanol (1). La actividad antituberculosis, basada en reportes previos, se atribuyó al compuesto 1. Además, se obtuvo clerosterol (2) por cristalización de una fracción activa frente a Staphylococcus aureus y Vibrio parahaemolyticus (MIC = 125 y 250 μg mL-1, respectivamente). Las dos estructuras fueron inferidas mediante interpretación y comparación de datos obtenidos por espectroscopía de IR-ATR y 1H RMN. En contraste con otros estudios, el compuesto 2 mostró una citotoxicidad no significativa contra la línea celular PC-3 (% IC = 21.05 ± 0.3 a 50 μg mL–1). Hasta donde sabemos, estos metabolitos se reportan por primera vez en C. amplivesiculatum y 1-octadecanol es un reporte muy raro de alcohol de cadena larga aislado de clorofitas.

Investigation of Copper-supported Ceria Nanofibers for Catalytic Oxidation of Diesel Soot

10.21203/rs.3.rs-295391/v1 ◽

2021 ◽

Author(s):

Dan Bahadur Pal ◽

Anupama Mishra

Keyword(s):

Photoelectron Spectroscopy ◽

Fixed Bed ◽

Tubular Reactor ◽

Soot Oxidation ◽

Diesel Soot ◽

Air Flow Rate ◽

Reaction Conditions ◽

Tight Contact ◽

Diesel Soot Oxidation ◽

Working Parameters

Abstract In the present research, CeO2 and CuO/CeO2 nanofibers were synthesized by electrospinning at 12 kV DC by maintaining a tip to collector distance of 10 cm. The morphology of the as-synthesized nanofibers was determined by scanning electron microscopy, and their elemental composition was verified by X-ray photoelectron spectroscopy. The activity of the prepared samples for diesel soot oxidation was determined in a bench-scale fixed bed tubular reactor, and effluent gases were analyzed by online gas chromatography. The variations of working parameters (air flow rate, catalyst-soot ratio, catalyst-soot contact type) were evaluated in a range to optimized reaction conditions for diesel soot oxidation. The catalyst with 40% CuO/CeO2 had the highest surface area, the smallest crystallite size, and the best activity for diesel soot oxidation (tight contact) at Tf = 318oC.