Conversion of ethene and propene adsorbed on Pt foil

The conversion of ethene and propene has been studied in the process of adsorption on Pt foil and in adsorbed state. Mainly C−C bond cleavage and limited C−C bond formation was observed in 323–523 K temperature interval.     

Efficient deprotection of N-benzyloxycarbonyl group from amino acids by hydroxyapatite-bound Pd catalyst in the presence of molecular hydrogen

Hydroxyapatite-bound Pd catalyst was found to be highly effective for the deprotection of N-benzyloxycarbonyl group from amino acids in the presence of molecular hydrogen. The catalyst was also applicable to the hydrogenolysis of a sterically encumbered core-Z-protected poly(amido amine) dendrimer, affording the dendritic amino compound in 99% yield.     

PdCl2-catalyzed hydrogenolysis of an Ar-Cl bond by sodium phosphinate in an aqueous alkaline medium

The hydrogenolysis of the Ar-Cl bond in chlorinated benzoic acids, anilines, and nitrogen-containing heterocycles by the action of NaH₂PO₂ in the presence of catalytic amounts of PdCl₂ and NaOH in an aqueous medium was studied. Under these conditions aryl chlorides were quantitatively converted into the corresponding arenes. Chloropyridines, such as 2-chloropyridine and 3, 5-dichloropicolinic acid, did not undergo hydrogenolysis even in the presence of an equivalent amount of NaI. A distinctortho effect was observed forortho-substituted substrates.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 607–609, March, 1993.     

纳米nah高化学反应活性

纳米氢化钠;氯苯氢解;肉桂醛选择还原;二甲亚砜金属取代反应;烯烃催化加氢     

DFT study of the mechanism of alkane hydrogenolysis by transition metal hydrides. 1. Interaction of silica-supported zirconium hydrides with methane

Model reactions of silica-supported zirconium hydrides (Si—O—)₃ZrH and (Si—O—)₂ZrH₂ with methane, resulting in cleavage of a C—H bond in the methane molecule and the formation of (Si—O—)₃ZrCH₃ and (Si—O—)₂Zr(H)CH₃ as products were studied using the DFT approach with the PBE density functional. The processes proceed as bimolecular reactions without preliminary formation of agostic complexes. According to calculations, zirconium dihydrides (Si—O—)₂ZrH₂ are more reactive toward the methane C—H bonds than zirconium monohydrides (Si—O—)₃ZrH. The calculated activation energies of the reactions with participation of zirconium dihydrides (Si—O—)₂ZrH₂ are in better agreement with the known experimental data for the Yermakov—Basset catalytic system.     

PRELIMINARY EXAMINATION OF THE CONCURRENT SYNTHESIS OF METHANOL IN SLURRY PHASE

本文报道了ｌ升浆液搅拌釜内一体化甲醇合成反应过程中涉及的甲醇连续羰基化、甲酸甲酯氢解和低温甲醇合成反应的初步考察结果。     

Protection Group Effects During α,γ‐Diol Lignin Stabilization Promote High‐Selectivity Monomer Production

Protection groups were introduced during biomass pretreatment to stabilize lignin's α,γ‐diol group during its extraction and prevent its condensation. Acetaldehyde and propionaldehyde stabilized the α,γ‐diol without any aromatic ring alkylation, which significantly increased final product selectivity. The subsequent hydrogenolysis catalyzed by Pd/C generated lignin monomers at near‐theoretical yields based on Klason lignin (48 % from birch, 20 % from spruce, 70 % from high‐syringyl transgenic poplar), and with high selectivity to a single 4‐n‐propanolsyringol product (80 %) in the case of the poplar. Unlike direct hydrogenation of native wood, hydrogenolysis of protected lignin with Ni/C also led to high selectivity to this single product (78 %), paving the way to high‐selectivity lignin upgrading with base metal catalysts. The use of extracted lignin facilitated valorization of polysaccharides, leading to high yields of all three major biomass polymers to a single major product.     

Synthesis of a novel tripod BODIPY dye bearing N-hydroxysuccinimide ester and its amidation

A novel tripod boron dipyrromethene (BODIPY) dye bearing N-hydroxysuccinimide ester was synthesized through its carboxylic acid precursor, and the functionality was confirmed by its amidation reaction with a primary amine. It is the first time that a reactive functional group was introduced onto a tripod BODIPY structure. All the new structures had been characterized by NMR, HRMS, and IR spectra. The introduction of an electron-donative diethylamine proved to be a key factor for the successful hydrogenolysis of the corresponding tris-substituted 1,3,5-triazine structure.     

Synthesis of Catechol‐, Pinacol‐, and Neopentylglycolborane through the Heterogeneous Catalytic B?B Hydrogenolysis of Diboranes(4)

A new synthetic approach to hydroboranes catechol‐, pinacol‐, and neopentylglycolborane has been developed. Starting from diboranes(4) B₂cat₂, B₂pin₂, or B₂neop₂, the respective boranes were obtained by heterogeneously catalyzed cleavage of the B? B bond in the respective diboranes with hydrogen. Group 10 metals were found to be effective catalysts for this reaction.     

Microcoulometric Determination of Sulfur and Chlorine by Combustion and Nitrogen by Hydrogenolysis

Abstract

The design of an improved open microcombustion tube and experimental conditions for the rapid, accurate and precise determination of sulfur and chlorine by microcoulometry are described. The design and operating conditions for a catalytic hydrogenolysis tube and scrubber tube for acid removal are also presented for the determination of nitrogen. Examples of the application of the above methods for these elements in petroleum and petrochemicals are presented.