The Experts below are selected from a list of 738 Experts worldwide ranked by ideXlab platform
Jie Wu - One of the best experts on this subject based on the ideXlab platform.
-
recent advances in sulfonylation reactions using Potassium sodium Metabisulfite
Chemical Communications, 2020Co-Authors: Shengqing Ye, Jie Wu, Min YangAbstract:Recently, sulfonylation reactions using Potassium/sodium Metabisulfite as the sulfur dioxide surrogate have been developed rapidly. In most cases, the transformations go through radical processes with the insertion of sulfur dioxide under mild conditions. Additionally, transition metal catalysis is applied in the reactions for the synthesis of sulfonyl-containing compounds. Among the approaches, photoinduced conversions under visible light or ultraviolet irradiation are also involved. In this updated report, the insertion of sulfur dioxide from Potassium Metabisulfite or sodium Metabisulfite is summarized.
-
inorganic sulfites as the sulfur dioxide surrogates in sulfonylation reactions
Chemical Communications, 2019Co-Authors: Shengqing Ye, Jie WuAbstract:Recent advances in the sulfonylation reactions by using inorganic sulfites as the source of sulfonyl group are reported. The approaches employing inorganic sulfites as sulfur dioxide surrogates are attractive and promising for the synthesis of sulfonyl compounds since inorganic sulfites are abundant, easily available and cheap. The transformations using inorganic sulfites as the source of sulfonyl group work efficiently, providing diverse sulfonyl compounds including sulfones and sulfonamides. The sulfonylation reactions can be performed under transition metal catalysis or through radical processes under catalyst- and additive-free conditions. In some cases, a photocatalyst is employed under visible-light irradiation to facilitate the transformation. For the sulfur dioxide surrogate of inorganic sulfites, Potassium Metabisulfite or sodium Metabisulfite has been broadly used in various transformations. However, the reactivities of inorganic sulfites in organic reactions still need to be explored.
Bojan Janković - One of the best experts on this subject based on the ideXlab platform.
-
Kinetic analysis of the nonisothermal decomposition of Potassium Metabisulfite using the model-fitting and isoconversional (model-free) methods
Chemical Engineering Journal, 2008Co-Authors: Bojan JankovićAbstract:Abstract The thermal decomposition kinetics of Potassium Metabisulfite was studied by thermogravimetry using nonisothermal experiments. The complete kinetic analysis was established by the following procedures: isoconversional methods (model-free) (including the Friedman (FR), Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO) and Vyazovkin (V) methods), master-plot method, the artificial isokinetic relationship and in addition the differential composite method. Firstly, it was established that the Friedman's and Vyazovkin's isoconversional methods are the best two methods for describing the dependence of apparent activation energy (Ea) on the degree of conversion (α) for the investigated decomposition process. Secondly, the appropriate conversion model (f(α)) of the process were selected by means of the “model-fitting” master-plot method. From the system studied, using the composite differential method we obtained the following kinetic triplet: f(α) = 2(1 − α)1/2, Ea = 121.9 kJ mol−1, A = 1.22 × 1012 min−1. Comparing both experimental and calculated thermoanalytical curves at constant heating rate assessed the adequate consistency of the kinetic triplet. It was concluded that the totally unambiguous choice of the reaction model is practically impossible based solely on the existing kinetic data, and because of this fact, the meaningful conclusions concerning the real mechanism of the investigated decomposition process should be based on additional microscopic observations.
-
A kinetic study of the thermal decomposition process of Potassium Metabisulfite: Estimation of distributed reactivity model
Journal of Physics and Chemistry of Solids, 2008Co-Authors: Bojan Janković, Slavko Mentus, M. JankovićAbstract:Abstract The thermal decomposition kinetics of Potassium Metabisulfite was studied by thermogravimetric (TG) and differential thermogravimetric (DTG) techniques using non-isothermal experiments. The apparent activation energy (Ea) is determined using the differential (Friedman) isoconversional method. The results of the Friedman's isoconversional analysis of the TG data suggests that the investigated decomposition process follows a single-step reaction and the observed apparent activation energy was determined as 122.4±2.1 kJ mol−1. A kinetic rate equation was derived for the decomposition process of Potassium Metabisulfite with contracting area model, f(α)=2(1−α)1/2, which is established using the Malek's kinetic procedure. The value of pre-exponential factor (A) is also evaluated and was found to be A=1.37×1012 min−1. By applying the Miura's procedure the distributed reactivity model (DRM) for investigated decomposition process was established. From the dependence α versus Ea, the experimental distribution curve of apparent activation energies, f(Ea), was estimated. By applying the non-linear least-squares analysis, it was found that the Gaussian distribution model (with distribution parameters E0=121.3 kJ mol−1 and σ=1.5 kJ mol−1) represents the best reactivity model for describing the investigated process. Using the Miura's method, the A values were estimated at five different heating rates and the average A values are plotted against Ea. The linear relationship between the A and Ea values was established (compensation effect). Also, it was concluded that the Ea values calculated by the Friedman's method and estimated distribution curve, f(Ea), are correct even in the case when the investigated decomposition process occurs through the single-step reaction mechanism.
Shengqing Ye - One of the best experts on this subject based on the ideXlab platform.
-
recent advances in sulfonylation reactions using Potassium sodium Metabisulfite
Chemical Communications, 2020Co-Authors: Shengqing Ye, Jie Wu, Min YangAbstract:Recently, sulfonylation reactions using Potassium/sodium Metabisulfite as the sulfur dioxide surrogate have been developed rapidly. In most cases, the transformations go through radical processes with the insertion of sulfur dioxide under mild conditions. Additionally, transition metal catalysis is applied in the reactions for the synthesis of sulfonyl-containing compounds. Among the approaches, photoinduced conversions under visible light or ultraviolet irradiation are also involved. In this updated report, the insertion of sulfur dioxide from Potassium Metabisulfite or sodium Metabisulfite is summarized.
-
inorganic sulfites as the sulfur dioxide surrogates in sulfonylation reactions
Chemical Communications, 2019Co-Authors: Shengqing Ye, Jie WuAbstract:Recent advances in the sulfonylation reactions by using inorganic sulfites as the source of sulfonyl group are reported. The approaches employing inorganic sulfites as sulfur dioxide surrogates are attractive and promising for the synthesis of sulfonyl compounds since inorganic sulfites are abundant, easily available and cheap. The transformations using inorganic sulfites as the source of sulfonyl group work efficiently, providing diverse sulfonyl compounds including sulfones and sulfonamides. The sulfonylation reactions can be performed under transition metal catalysis or through radical processes under catalyst- and additive-free conditions. In some cases, a photocatalyst is employed under visible-light irradiation to facilitate the transformation. For the sulfur dioxide surrogate of inorganic sulfites, Potassium Metabisulfite or sodium Metabisulfite has been broadly used in various transformations. However, the reactivities of inorganic sulfites in organic reactions still need to be explored.
Andre Shavnya - One of the best experts on this subject based on the ideXlab platform.
-
palladium catalyzed synthesis of hetero aryl alkyl sulfones from hetero aryl boronic acids unactivated alkyl halides and Potassium Metabisulfite
ChemInform, 2016Co-Authors: Andre Shavnya, Kevin D Hesp, Vincent Mascitti, Aaron SmithAbstract:A direct synthesis of aryl alkyl sulfones is achieved by Pd-catalyzed reaction of arylboronic acids, alkyl halides, and Potassium Metabisulfite as source of the SO2-unit.
-
palladium catalyzed synthesis of hetero aryl alkyl sulfones from hetero aryl boronic acids unactivated alkyl halides and Potassium Metabisulfite
Angewandte Chemie, 2015Co-Authors: Andre Shavnya, Kevin D Hesp, Vincent Mascitti, Aaron SmithAbstract:A palladium-catalyzed one-step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, Potassium Metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X-ray diffraction analysis.
-
Palladium‐Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite
Angewandte Chemie (International ed. in English), 2015Co-Authors: Andre Shavnya, Kevin D Hesp, Vincent Mascitti, Aaron C. SmithAbstract:A palladium-catalyzed one-step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, Potassium Metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X-ray diffraction analysis.
Aaron C. Smith - One of the best experts on this subject based on the ideXlab platform.
-
Palladium‐Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite
Angewandte Chemie (International ed. in English), 2015Co-Authors: Andre Shavnya, Kevin D Hesp, Vincent Mascitti, Aaron C. SmithAbstract:A palladium-catalyzed one-step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, Potassium Metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X-ray diffraction analysis.