One-pot conversion of cellulose to isosorbide using supported metal catalysts and ion-exchange resin

2015 ◽  
Vol 67 ◽  
pp. 59-63 ◽  
Author(s):  
Aritomo Yamaguchi ◽  
Osamu Sato ◽  
Naoki Mimura ◽  
Masayuki Shirai
2019 ◽  
Vol 21 (17) ◽  
pp. 4769-4785 ◽  
Author(s):  
Jaime Mazarío ◽  
Miriam Parreño Romero ◽  
Patricia Concepción ◽  
Marvin Chávez-Sifontes ◽  
Rolando A. Spanevello ◽  
...  

One-pot selective hydrogenation of levoglucosenone to Cyrene and levoglucosanol was successfully carried out by using Pd/ZrO2 and Pt/ZrO2 catalysts, respectively.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chengtao Yue ◽  
Qi Xing ◽  
Peng Sun ◽  
Zelun Zhao ◽  
Hui Lv ◽  
...  

AbstractCatalyst deactivation caused by the aggregation of active metal species in the reaction process poses great challenges for practical applications of supported metal catalysts in solid-liquid catalysis. Herein, we develop a hypercrosslinked polymer integrated with N-heterocyclic carbene (NHC) as bifunctional support to stabilize palladium in heterogeneous C-C bond formations. This polymer supported palladium catalyst exhibits excellent stability in the one-pot fluorocarbonylation of indoles to four kinds of valuable indole-derived carbonyl compounds in cascade or sequential manner, as well as the representative Suzuki-Miyaura coupling reaction. Investigations on stabilizing effect disclose that this catalyst displays a molecular fence effect in which the coordination of NHC sites and confinement of polymer skeleton contribute together to stabilize the active palladium species in the reaction process. This work provides new insight into the development of supported metal catalysts with high stability and will also boost their efficient applications in advanced synthesis.


2020 ◽  
Author(s):  
Chengtao Yue ◽  
Qi Xing ◽  
Peng Sun ◽  
Zelun Zhao ◽  
Hui Lv ◽  
...  

Abstract Catalyst deactivation caused by the aggregation of active metal species in the reaction process poses great challenges for practical applications of supported metal catalysts in solid-liquid catalysis. Herein, we developed a hypercrosslinked polymer integrated with N-heterocyclic carbene (NHC) as bifunctional support to stabilize palladium in heterogeneous C-C bond formations. This polymer supported palladium catalyst exhibits excellent stability in the one-pot fluorocarbonylation of indoles to four kinds of valuable indole-derived carbonyl compounds in cascade or sequential manner, as well as the representative Suzuki-Miyaura coupling reaction. Stabilizing mechanism investigations disclose that this catalyst displays a molecular fence effect in which the coordination of NHC sites and confinement of polymer skeleton contribute together to stabilize the active palladium species in the reaction process. This work provides new insight into the development of supported metal catalysts with high stability and will also boost their efficient applications in advanced synthesis.


2020 ◽  
Vol 42 ◽  
pp. 101324
Author(s):  
Shin Hye Cho ◽  
Deliana Dahnum ◽  
Seok-Hyeon Cheong ◽  
Hee Won Lee ◽  
Ung Lee ◽  
...  

2014 ◽  
Vol 68 (6) ◽  
Author(s):  
Xiong Liu ◽  
Dong-Liang Yang ◽  
Jia-Jia Liu ◽  
Jing Zhou ◽  
Nana Zhao

AbstractThis study concerns the preparation of a new eburnamine-type alkaloid, methyl (3α,14β,15β,16α)-17,18-didehydro-14,15-dihydroeburnamine-15-methoxy-14-carboxylate (VIII). This alkaloid was prepared from (+)-17,18-dehydroapovincamine (V) using Lewis acid and/or ion exchange resin as catalyst. The hydroalkoxylation reaction of V with methanol was investigated in terms of catalyst, solvent, temperature, and time of reaction. A one-pot method for synthetising this alkaloid was established. The optimal conditions for the reaction are discussed.


2016 ◽  
Vol 52 ◽  
pp. 171-176
Author(s):  
M. Palkina ◽  
O. Metlitska

The aim of the research – adaptation, optimization and using of existing DNA extraction methods from bees’ biological material with the reagent «Chelex-100" under complex economic conditions of native laboratories, which will optimize labour costs and improve the economic performance of DNA extraction protocol. Materials and methods. In order to conduct the research the samples of honey bees’ biological material: queen pupae exuviae, larvae of drone brood, some adult bees’ bodies (head and thorax) were selected. Bowl and drone brood were obtained from the experimental bee hives of Institute of Apiculture nd. a. P. I. Prokopovich of NAAS. DNA extraction from biosamples of Apis mellifera ssp. was carried out using «Chelex-100®» ion exchange resin in different concentrations and combinations. Before setting tests for determination of quantitative and quality indexes, dilution of DNA samples of the probed object was conducted in ratio 1:40. The degree of contamination with protein and polysaccharide fractions (OD 260/230), quantitative content of DNA (OD 260/280) in the extracted tests were conducted using spectrophotometer of «Biospec – nano» at the terms of sample volume in 2 µl and length of optical way in 0,7 mm [7]. Verification of DNA samples from biological material of bees, isolated by «Chelex-100®», was conducted after cold keeping during 24 hours at 20°C using PСR with primaries to the fragment of gene of quantitative trait locus (QTL) Sting-2 of next structure [8]:  3' – CTC GAC GAG ACG ACC AAC TTG – 5’; 3' – AAC CAG AGT ATC GCG AGT GTT AC – 5’ Program of amplification: 94 °C – 5 minutes – 1 cycle; 94 °C – 1 minute, 57°C – 1 minute, 72 °C – 2 minutes – 30 cycles; elongation after 72°C during 2 minutes – 1 cycle. The division of obtained amplicons was conducted by gel electrophoresis at a low current – 7 µÀ, in 1,5 % agarose gel (Sigma ®) in TAE buffer [7]. The results. At the time of optimization of DNA isolation methods, according to existing methods of foreign experts, it was found optimal volume of ion exchange resin solution was in the proposed concentration: instead of 60 µl of solution used 120 µl of «Chelex-100®», time of incubation was also amended from 30 minutes to 180 minutes [9]. The use of the author's combination of method «Chelex-100®» with lysis enzymes, proteinase K and detergents (1M dithiothreitol), as time of incubation was also amended, which was reduced to 180 minutes instead of the proposed 12 hours [10]. Changes in quality characteristics of obtained DNA in samples after reduction in incubation time were not found. Conclusions. The most economical method of DNA isolation from bees’ biological material is 20% solution of «Chelex-100» ion exchange resin with the duration of the incubation period of 180 minutes. It should also be noted that the best results can be obtained from exuviae, selected immediately after the queen’s exit from bowl, that reduces the likelihood of DNA molecules destruction under the influence of nucleases activation, but not later than 12 hours from release using the technology of isolated obtain of queens.


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