Abstract H 2 O as a well‐known efficient oxidant is widely used in the chemical industry mainly because of its homolytic cleavage into . OH (stronger oxidant), but this reaction always competes with generation resulting waste. Here, we fabricate heterogeneous Fenton‐type Fe‐based catalysts containing Fe‐N x sites and Fe/Fe 3 C nanoparticles model to study competition. low spin state provides active site for generation. C, particular Fe promotes cleavages OH, (Fe 0 main component) more...

Two catalysts in one! Catalyst tuning with achiral additives effectively constructed and reconstructed a chiral environment around the catalyst [YLi3{tris(binaphthoxide)}], which enabled tandem asymmetric catalysis from substrates using single component one pot (see scheme: A=cyanation reaction, B=nitroaldol reaction). Supporting information for this article is available on WWW under http://www.wiley-vch.de/contents/jc_2002/2002/z19598_s.pdf or author. Please note: The publisher not...

A hypervalent iodine(III) reagent plays a novel role as an efficient coupling to promote the direct condensation between carboxylic acids and alcohols or amines provide esters, macrocyclic lactones, amides, well peptides without racemization. The regeneration of iodosodilactone (1) can also be readily achieved. intermediate acyloxyphosphonium ion C from activation acid is thought involved in present esterification reaction.

Full details of a catalytic asymmetric cyano-ethoxycarbonylation reaction promoted by heterobimetallic YLi3tris(binaphthoxide) complex (YLB 1), especially mechanistic studies, are described. In the cyanation aldehydes with ethyl cyanoformate, three achiral additives, H2O, tris(2,6-dimethoxyphenyl)phosphine oxide (3a), and BuLi, were required to achieve high reactivity enantioselectivity (up >99% yield up 98% ee). The roles additives pathway investigated in detail. situ IR analysis revealed...

Abstract A series of insoluble heteropolytungstate salts, Cs x H 3–x PW 12 O 40 (x = 1–3), were prepared and applied to the selective hydrolysis microcrystalline cellulose sugars in aqueous phase. active toward into total reducing (TRS) glucose, which are important products for application biofuels. The conversion yield main increased with increasing acidity catalyst. 1 2 exhibited best catalytic activity terms yields TRS while 2.2 0.8 showed highest selectivity glucose.

The effect of Zr modification on the catalytic activity Co/SiO2 was investigated for nonoxidative propane dehydrogenation. Isolated SiO2 surface sites were prepared by organometallic synthesis using Zr(O t Bu)4 as a precursor. resulting Zr/SiO2 support functionalized with Co2+ ions via strong electrostatic adsorption. Spectroscopic (diffuse reflectance infrared Fourier transform spectroscopy, UV-vis, electron paramagnetic resonance) and microscopic characterization (transmission microscopy,...

Transition metal-catalyzed isocyanide insertion has served as a fundamental and important chemical transformation. Classical usually occurs between organohalides nucleophiles, which normally involves tedious non-atom-economical prefunctionalization processes. However, oxidative C-H/N-H offers an efficient green alternative. Herein, nickel-catayzed of aminoquinoline benzamides been developed. Different kinds iminoisoindolinone derivatives could be synthesized in good yields by utilizing...

Aiming to develop efficient and general strategies for construction of complex diverse polycyclic skeletons, we have successfully developed [4+3]IMPC (intramolecular parallel cycloaddition) cyclopropane 1,1-diesters with [3]dendralenes. With a combination the subsequent [4+n] cycloadditions, trans-[5.3.0]decane skeleton its corresponding structurally variants could be constructed efficiently. This novel [4+3] cycloaddition reaction mode donor-acceptor cyclopropanes proceeds as result...

The “Ten-Year Fishing Ban” policy in the Yangtze River Basin aims to restore ecological diversity but poses significant challenges for fishermen their transition alternative livelihoods. This study focuses on who worked Poyang Lake, using sustainable livelihood framework and theory of planned behavior, combined with fuzzy-set qualitative comparative analysis (fsQCA) descriptive statistics, explore interaction effects capital, cognition, compensation policies fishermen’s behavioral responses....

Food resources are the fundamental basis for survival and reproduction of animals. Diet research is foundation understanding their ecological habits great significance evaluating status carrying out effective protection management. South China sika deer (Cervus nippon kopschi) most endangered subspecies wild in China, with a small population shrinking distribution area. Here, we used DNA metabarcoding technology to study diet composition C. n. kopschi Taohongling Sika Deer National Nature...

[reaction: see text] An efficient two-step conversion of alpha,beta-unsaturated aldehydes into optically active gamma-oxy-alpha,beta-unsaturated nitriles is described. First, catalytic asymmetric cyanation-ethoxycarbonylation using (S)-YLi(3)tris(binaphthoxide) (YLB) afforded chiral allylic cyanohydrin carbonate. Second, a [3,3]-sigmatropic rearrangement proceeded without racemization under thermal conditions to give nitriles. Lewis acids were also effective for the rearrangement, and...

Abstract p ‐Iodotoluene difluoride ( ‐Tol‐IF 2 ) has been found to be a general reagent for the effective introduction of various oxygen‐containing functionalities including tosyloxy, mesyloxy, acetoxy, phosphoryloxy, methoxy, ethoxy and isopropoxy at α‐position β‐dicarbonyl compounds. These transformations can readily realized by use combined ‐iodotoluene nucleophilic compounds such as ‐toluenesulfonic acid, methanesulfonic acetic diphenyl phosphate, methanol, ethanol propan‐2‐ol under mild...

Abstract H 2 O as a well‐known efficient oxidant is widely used in the chemical industry mainly because of its homolytic cleavage into . OH (stronger oxidant), but this reaction always competes with generation resulting waste. Here, we fabricate heterogeneous Fenton‐type Fe‐based catalysts containing Fe‐N x sites and Fe/Fe 3 C nanoparticles model to study competition. low spin state provides active site for generation. C, particular Fe promotes cleavages OH, (Fe 0 main component) more...

Abstract Cyclohexanone was chosen as a model substrate to evaluate certain catalysts for the hydrodeoxygenation of aliphatic ketones in fixed‐bed reactor. The experimental results indicated that alkali‐treated Ni/HZSM‐5 exhibited excellent performance this reaction. Two aspects catalyst are enhanced by alkaline treatment; amount strong acid sites on is sharply reduced, and also large number mesopores generated catalyst. decrease suppresses formation low‐boiling products aldol‐condensation...

This study was performed to develop a highly efficient method whereby desulfurization could be completed in 0.5 h under ultraviolet light, at room temperature, and the presence of trialkylphosphine. Using this method, deoxyglycosides produced from sulfur-containing glycosides almost quantitative yields. The much higher reactivity with triethylphosphine versus that triethylphosphite is also discussed.

Abstract A highly efficient, green, and regioselective method for the benzylation of diols polyols was developed. With use Ag 2 O (0.6 equiv.) tetrabutylammonium bromide (0.1 as co‐catalysts, iron(III)‐catalyzed reaction proceeded to completion at 40 °C within 2–3 h gave products in high yields with regioselectivities. mechanism involving principle enhanced basicity by soft anions proposed.

Creating active and stable electrocatalysts remains a highly desirable critical goal in the fields of catalysis clean energy conversion. Single-atom catalyst (SAC), as new research frontier heterogeneous catalysis, has demonstrated emerging prospects for many electrocatalytic reactions. Support-assisted pyrolysis approaches are widely used synthesis single-atom electrocatalysts. While extensive efforts have been devoted to increase loading atomically dispersed metal sites, role support...