826-29-9Relevant academic research and scientific papers
Multifunctional Catalytic Surface Design for Concerted Acceleration of One-Pot Hydrosilylation-CO2 Cycloaddition
Usui, Kei,Miyashita, Kodai,Maeda, Kyogo,Manaka, Yuichi,Chun, Wang-Jae,Inazu, Koji,Motokura, Ken
supporting information, p. 9372 - 9376 (2019/11/28)
Silica-supported Rh-ammonium iodide catalyst showed high performance for hydrosilylation-CO2 cycloaddition reaction sequences. The catalyst was prepared by surface grafting of Rh and the silane-coupling reaction of the ammonium iodide moiety. The acceleration of each catalytic reaction was realized due to the concerted catalysis between Rh species, immobilized organic functions, and surface Si-OH groups. As a result, good to excellent yields of silyl carbonates were obtained from epoxyolefins, hydrosilanes, and CO2 under mild reaction conditions.
Highly regio- And stereoselective synthesis of cyclic carbonates from biomass-derived polyols: Via organocatalytic cascade reaction
Zhou, Hui,Zhang, Hui,Mu, Sen,Zhang, Wen-Zhen,Ren, Wei-Min,Lu, Xiao-Bing
supporting information, p. 6335 - 6341 (2019/12/03)
The cascade reaction of CO2, vicinal diols, and propargylic alcohol, was firstly achieved by dual Lewis base (LB) organocatalytic systems involving LB-CO2 adducts and commercially available organic amines. This methodology could overcome the chemical inertness of CO2, providing an alternative route to various functionalized five-membered cyclic carbonates in moderate to high yields under mild reaction conditions (25 °C, 1.0 atm of CO2). More importantly, this method could also be applied for facile and efficient synthesis of chiral polycyclic carbonates from biomass-derived polyols with complete configuration retention of chiral centers. This study provides an environment-friendly, scalable and cost effective protocol to construct value-added cyclic carbonates with multi-functional groups and chiral centers.
MnIII Porphyrins: Catalytic Coupling of Epoxides with CO2 under Mild Conditions and Mechanistic Considerations
Milani, Jorge L. S.,Meireles, Alexandre M.,Bezerra, Werberson A.,Martins, Dayse. C. S.,Cangussu, Danielle,das Chagas, Rafael P.
, p. 4393 - 4402 (2019/08/01)
A series of 5,10,15,20-tetrakis(2,3-dichlorophenyl)porphyrinate complexes of manganese(III) [MnIII(T2,3DCPP)X] with six different axial ligands (X=NO3 ?, AcO?, IO3 ?, Br?, Cl?, HO?) were investigated as catalysts in the cycloaddition reactions of CO2 and styrene oxide (SO), under mild conditions, i. e., atmospheric pressure and 60 °C. [MnIIIT(2,3DCPP)IO3] showed the best catalytic performance, selectively producing the respective cyclic carbonate from diverse epoxides using tetrabutylammonium bromide as a nucleophile source. Mechanistic considerations were inferred from electronic spectra and spectrophotometric titrations, showing that there are a series of equilibriums involved in the formation of the catalytic active species. Stability constants for the proposed equilibrium models were determined using SQUAD software. A catalytic cycle has been proposed based on those observations.
Straightforward synthesis of MTW-type magnesium silicalite for CO2 fixation with epoxides under mild conditions
Wen, Haimeng,Xie, Jingyan,Zhou, Yang,Zhou, Yu,Wang, Jun
, p. 5725 - 5735 (2019/10/23)
Aluminum-free magnesium silicalite with MTW topology (Mg-Si-ZSM-12) was fabricated via a straightforward hydrothermal synthesis route involving an initial acid co-hydrolysis step. Mg incorporation endowed superior basic properties to the MTW framework, as illustrated by CO2 sorption and temperature programmed desorption plus the activity in a typical basic reaction, Knoevenagel condensation. Mg-Si-ZSM-12 catalyzed the coupling of atmospheric CO2 with epoxides and led to the efficient production of cyclic carbonates with high yield and selectivity at relatively low temperature (down to 60 °C). The present strategy afforded a zeolitic solid base with regular 12-membered ring microporous channels that has potential application in CO2 fixation.
Aqueous-microwave synthesized carboxyl functional molecular ribbon coordination framework catalyst for the synthesis of cyclic carbonates from epoxides and CO2
Kathalikkattil, Amal Cherian,Kim, Dong-Woo,Tharun, Jose,Soek, Han-Geul,Roshan, Roshith,Park, Dae-Won
, p. 1607 - 1616 (2014/03/21)
A carboxyl-containing coordination polymer catalyst {Cu(Hip) 2(Bpy)}n (CHB) was synthesized rapidly in an aqueous medium using microwave energy and characterized for its structure, morphology, acid-base sites and heterogeneity using experimental and physicochemical techniques. The microwave route was established as competent with the hydrothermal pathway. Exploration of the coordination modes of metal-organic framework (MOF) ligands, especially carboxyl spacers, in achieving reactive functional groups is herein illustrated as crucial rather than focusing merely on the porosity of MOF catalysts. The work represents the first report of a carboxyl-containing MOF class material employed for synthesizing cyclic carbonates from epoxide and CO2. The metal-carboxyl mediated cycloaddition of allyl glycidyl ether and CO2 by the cooperative influence of Cu2+ and the COOH of CHB was synergistically enhanced by an ionic liquid co-catalyst to obtain allyl glycidyl carbonate in 89% yield at optimised reaction conditions. The epoxide substrate scope, effect of reaction parameters and catalyst recyclability (up to 5 cycles) were also studied.
Microwave-assisted, rapid cycloaddition of allyl glycidyl ether and CO 2 by employing pyridinium-based ionic liquid catalysts
Tharun, Jose,Kathalikkattil, Amal Cherian,Roshan, Roshith,Kang, Dong-Heon,Woo, Hee-Chul,Park, Dae-Won
, p. 31 - 34 (2014/06/24)
This study investigated the use of pyridinium-based ionic liquids (ILs) as an efficient catalyst for the rapid solvent-free microwave-assisted cycloaddition of allyl glycidyl ether (AGE) and CO2 to yield allyl glycidyl carbonate (AGC) under moderate reaction conditions. The cycloaddition reaction occurred over a short reaction time of 30 s, resulting in a high turnover frequency (TOF) ranging from 200 to 7000 h- 1. The effects of alkyl chain length and anion of pyridinium-based catalysts on the cycloaddition reactivity were studied. The effects of reaction parameters such as the amount of catalyst, microwave power, CO2 pressure, and reaction time were also investigated.
Pd-catalyzed reaction of allyl carbonate with polyols: The role of CO 2 in transesterification versus etherification of glycerol
Gordillo, Alvaro,Lloyd-Jones, Guy C.
supporting information; scheme or table, p. 2660 - 2665 (2012/04/11)
An intermolecular Pd/PPh3-catalyzed transesterification of diallyl carbonate with glycerol to generate glycerol carbonate has been developed. Analysis of the reaction kinetics in THF indicates a first-order dependence on Pd and diallyl carbonate, that the Pd bears two phosphines during the turnover limiting event, and that increasing the glycerol concentration inhibits reaction, possibly via change in the polarity of the medium. 13C isotopic labeling studies demonstrate that the Pd-catalyzed transesterification requires at least one allyl carbonate moiety and that there is rapid equilibrium of the allyl carbonate with CO2 in solution, even when present only at low concentrations. A mechanism that is consistent with these results involves oxidative addition of the allyl carbonate to Pd followed by reversible decarboxylation, with the intermediate I·1- and I·3-allyl Pd alkoxides mediating direct and indirect transesterification reactions with the glycerol. Using this model, successful simulations of the kinetics of reactions conducted under atmospheres of N2 or CO2 could be achieved, including switching in selectivity between etherification and transesterification in the early stages of reaction. Reactions with the higher polyols threitol and erythritol are also efficient, generating the terminal (1,2) monocarbonates with high selectivity. It's a gas: A Pd-catalyzed transesterification of diallyl carbonate with polyols has been developed. The CO2 concentration is shown to control the relative rates of etherification and transesterification. Kinetic and isotopic labeling studies suggest that intermediate I·1-allyl Pd alkoxides mediate indirect intermolecular transesterification. The higher polyols erythritol and threitol selectively generate monocarbonates. Copyright
Quaternary ammonium ionic liquids as Bi-functional catalysts for one-step synthesis of dimethyl carbonate from ethylene oxide, carbon dioxide and methanol
Li, Jian,Wang, Liguo,Shi, Feng,Liu, Shimin,He, Yude,Lu, Liujin,Ma, Xiangyuan,Deng, Youquan
experimental part, p. 339 - 346 (2011/12/22)
One kind of novel ionic liquids (ILs) with a tertiary amino moiety and a quaternary ammonium group were synthesized and identified by FT-IR, 1H and 13C NMR. The elemental chemical state and basicity of ILs were determined by XPS and Hammett indicator method, respectively. Then the catalytic performance of these bi-functional catalysts was investigated in one-step synthesis of dimethyl carbonate (DMC) from ethylene oxide (EO), carbon dioxide and methanol. The best catalytic performance with 99% EO conversion and a maximum of 74% DMC selectivity was obtained using [N111,6N11]I as catalyst under optimized reaction conditions. And the catalyst could be reused for several times. Normally, stronger basicity could be obtained by altering the anions with different nucleophilicity in ILs and a better catalytic activity could be achieved correspondingly. A mechanism that both the ring opening of epoxide through nucleophilic attacks and the transesterification play an important role in the reaction was proposed based on experimental results.
CONVENIENT SYNTHESES OF CYCLIC CARBONATES BY NEW REACTION OF OXIRANES WITH β-BUTYROLACTONE
Nishikubo, Tadatomi,Iizawa, Takashi,Iida, Makoto,Isobe, Naoki
, p. 3741 - 3744 (2007/10/02)
Cyclic carbonates were synthesized by reactions of the corresponding oxiranes with β-butyrolactone using quaternary salts such as tetrabutylammonium bromide or 18-crown-6=KBr as catalyst.
