An environmentally benign catalytic system for alkene epoxidation with hydrogen peroxide electrogenerated in situ

2006 ◽  
Vol 8 (10) ◽  
pp. 900 ◽  
Author(s):  
Kam-Piu Ho ◽  
Tak Hang Chan ◽  
Kwok-Yin Wong
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic System ◽  
Environmentally Benign

scholarly journals Epoxidation of Soybean Oil Catalyzed by [π-C5H5NC16H33]3[PW4O16] with Hydrogen Peroxide and Ethyl Acetate as Solvent

2011 ◽  
Vol 6 (8) ◽  
pp. 1934578X1100600
Author(s):  
Shuang-Fei Cai ◽  
Li-Sheng Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Soybean Oil ◽  
Ethyl Acetate ◽  
Catalytic System ◽  
Elemental Analysis ◽  
Environmentally Benign ◽  
High Recovery ◽  
Highly Efficient ◽  
Excellent Activity

A new environmentally benign and highly efficient catalytic system [π-C5H5NC16H33]3[PO4(WO3)4]/H2O2/CH3COOC2H5 for the epoxidation of soybean oil displayed excellent activity and high recovery. The change of the catalyst during the reaction was investigated by elemental analysis, FTIR and 31P NMR.

Bimetallic titanium complex catalyzed enantioselective oxidation of thioethers using aqueous H2O2 as a terminal oxidant

RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 47732-47739 ◽  
Author(s):  
Prasanta Kumar Bera ◽  
Naveen Gupta ◽  
Sayed H. R. Abdi ◽  
Noor-ul H. Khan ◽  
Rukhsana I. Kureshy ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic System ◽  
Sulfide Oxidation ◽  
Environmentally Benign ◽  
Aqueous Hydrogen Peroxide ◽  
Titanium Complex ◽  
Enantioselective Oxidation ◽  
Highly Efficient

This study represents a highly efficient sulfide oxidation catalytic system using a non-toxic Ti-catalyst and environmentally benign aqueous hydrogen peroxide.

scholarly journals Direct propylene epoxidation with oxygen enabled by photo-electro-heterogeneous catalytic system

2021 ◽  
Author(s):  
Myohwa Ko ◽  
Yongseon Kim ◽  
Jinwoo Woo ◽  
Rashmi Mehrotra ◽  
Pankaj Sharma ◽  
...  
Keyword(s):  
Catalytic System ◽  
Environmentally Benign ◽  
Ambient Conditions ◽  
Propylene Epoxidation ◽  
Epoxidation Of Propylene ◽  
Heterogeneous Catalytic ◽  
External Bias ◽  
Heterogeneous Catalytic System ◽  
Sacrificial Agent

Abstract Propylene oxide (PO) is a crucial feedstock in the plastic industry. The direct epoxidation of propylene using O2 is considered to be the most promising means of producing PO, but it remains challenging. Here, we report on an integrated photo-electro-heterogeneous catalytic system for propylene epoxidation with O2. Bismuth vanadate (or TiO2) photocatalyst and Co-based electrocatalyst produce H2O2 and titanium silicalite-1 heterogeneous catalyst epoxidises propylene to PO with the in situ generated H2O2. This system enables PO production with O2 as the sole oxidising agent under light irradiation without using H2, a sacrificial agent, or external bias. It stably produces PO for 24 h with high selectivity (≥ 98%) under ambient conditions. These results demonstrate the potential of this new catalytic system to produce chemical compounds in an environmentally benign manner.

scholarly journals Kinetic resolution of indolines by asymmetric hydroxylamine formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gang Wang ◽  
Ran Lu ◽  
Chuangchuang He ◽  
Lei Liu
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Synthesis ◽  
Late Stage ◽  
Kinetic Resolution ◽  
High Efficiency ◽  
Bond Formation ◽  
Bioactive Molecules ◽  
Environmentally Benign ◽  
Secondary Amines

AbstractCatalytic kinetic resolution of amines represents a longstanding challenge in chemical synthesis. Here, we described a kinetic resolution of secondary amines through oxygenation to produce enantiopure hydroxylamines involving N–O bond formation. The economic and practical titanium-catalyzed asymmetric oxygenation with environmentally benign hydrogen peroxide as oxidant is applicable to a range of racemic indolines with multiple stereocenters and diverse substituent patterns in high efficiency with efficient chemoselectivity and enantio-discrimination. Late-stage asymmetric oxygenation of bioactive molecules that are otherwise difficult to synthesize was also explored.

scholarly journals Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3844
Author(s):  
Lijuan Li ◽  
Bingdong Li ◽  
Liwei Feng ◽  
Xiaoqiu Zhang ◽  
Yuqian Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction System ◽  
Reaction Medium ◽  
Pure Tio2 ◽  
H2o2 Production ◽  
Tio2 Photocatalyst ◽  
H2o2 Decomposition ◽  
Spin Resonance ◽  
Photocatalytic Synthesis

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F− modification inhibits the H2O2 decomposition through the formation of the ≡Ti–F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F− modification and without F− modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

Effects of hydrogen peroxide and hypochlorite on membrane potential of mitochondria in situ in rat heart cells

1991 ◽  
Vol 69 (11) ◽  
pp. 1705-1712 ◽  
Author(s):  
Noburu Konno ◽  
K. J. Kako
Keyword(s):  
Hydrogen Peroxide ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Rat Heart ◽  
Mitochondrial Membrane ◽  
Isolated Rat Heart ◽  
Heart Mitochondria ◽  
High Concentrations ◽  
Isolated Rat

Hydrogen peroxide (H2O2) and hypochlorite (HOCl) cause a variety of cellular dysfunctions. In this study we examined the effects of these agents on the electrical potential gradient across the inner membrane of mitochondria in situ in isolated rat heart myocytes. Myocytes were prepared by collagenase digestion and incubated in the presence of H2O2 or HOCl. Transmembrane electrical gradients were measured by distribution of [3H]triphenylmethylphosphonium+, a lipophilic cation. The particulate fraction was separated from the cytosolic compartment first by permeabilization using digitonin, followed by rapid centrifugal sedimentation through a bromododecane layer. We found that the mitochondrial membrane potential (161 ± 7 mV, negative inside) was relatively well maintained under oxidant stress, i.e., the potential was decreased only at high concentrations of HOCl and H2O2 and gradually with time. The membrane potential of isolated rat heart mitochondria was affected similarly by H2O2 and HOCl in a concentration- and time-dependent manner. High concentrations of oxidants also reduced the cellular ATP level but did not significantly change the matrix volume. When the extra-mitochondrial free calcium concentration was increased in permeabilized myocytes, the transmembrane potential was decreased proportionally, and this decrease was potentiated further by H2O2. These results support the view that heart mitochondria are equipped with well-developed defense mechanisms against oxidants, but the action of H2O2 on the transmembrane electrical gradient is exacerbated by an increase in cytosolic calcium. Keywords: ATP, calcium, cardiomyocyte, cell defense, mitochondrial membrane potential, oxidant, triphenylmethylphosphonium.

Sign in / Sign up

Export Citation Format

Share Document