19424-30-7Relevant academic research and scientific papers
Highly efficient conversion of CO2 to cyclic carbonates with a binary catalyst system in a microreactor: Intensification of "electrophile-nucleophile" synergistic effect
Li, Ming-Ran,Zhang, Ming-Chao,Yue, Tian-Jun,Lu, Xiao-Bing,Ren, Wei-Min
, p. 39182 - 39186 (2018)
An intensification of the "electrophile-nucleophile" synergistic effect was achieved in a microreactor for the coupling reaction of CO2 and epoxides mediated by the binary Al complex/ternary ammonium salt catalyst system. The microreactor techn
Amidinate Aluminium Complexes as Catalysts for Carbon Dioxide Fixation into Cyclic Carbonates
Meléndez, Danay Osorio,Lara-Sánchez, Agustín,Martínez, Javier,Wu, Xiao,Otero, Antonio,Castro-Osma, José A.,North, Michael,Rojas, René S.
, p. 2271 - 2277 (2018)
A series of inexpensive and sustainable amidinate aluminium complexes has been developed as catalysts for the chemical fixation of carbon dioxide into cyclic carbonates. The reactions using terminal epoxides as substrates were carried out at room temperat
A rapid and effective synthesis of propylene carbonate using a supercritical CO2-ionic liquid system
Kawanami, Hajime,Sasaki, Akiyoshi,Matsui, Keitaro,Ikushima, Yutaka
, p. 896 - 897 (2003)
The synthesis of propylene carbonate from propylene oxide and carbon dioxide under supercritical conditions in the presence of 1-octyl-3-methylimidazolium tetrafluoroborate was achieved in nearly 100% yield and 100% selectivity within 5 minutes, whose TOF value is 77 times larger than those so far reported.
Cr(salophen) Complex Catalyzed Cyclic Carbonate Synthesis at Ambient Temperature and Pressure
Castro-Osma, José A.,Lamb, Katie J.,North, Michael
, p. 5012 - 5025 (2016)
The combination of a chromium(III) salophen bromide complex and tetrabutylammonium bromide is shown to catalyze the reaction between terminal epoxides and carbon dioxide at ambient temperature and 1 bar carbon dioxide pressure and between internal epoxide
Synthesis of helical aluminium catalysts for cyclic carbonate formation
Gaona, Miguel A.,De La Cruz-Martínez, Felipe,Fernández-Baeza, Juan,Sánchez-Barba, Luis F.,Alonso-Moreno, Carlos,Rodríguez, Ana M.,Rodríguez-Diéguez, Antonio,Castro-Osma, José A.,Otero, Antonio,Lara-Sánchez, Agustín
, p. 4218 - 4227 (2019)
Helical aluminium complexes [Al2X4(μ-nbptam)] (X = Me 1, Et 2), [Al2X4(μ-fbpam)] (R = Me 3, Et 4), [Al3X7(μ-nbptam)] (X = Me 5, Et 6) and [Al3X7(μ-fbpam)] (X = Me 7, E
Synthesis of Cyclic Carbonates Catalysed by Aluminium Heteroscorpionate Complexes
Martínez, Javier,Castro-Osma, José A.,Earlam, Amy,Alonso-Moreno, Carlos,Otero, Antonio,Lara-Sánchez, Agustín,North, Michael,Rodríguez-Diéguez, Antonio
, p. 9850 - 9862 (2015)
New aluminium scorpionate based complexes have been prepared and used for the synthesis of cyclic carbonates from epoxides and carbon dioxide. Bimetallic aluminium(heteroscorpionate) complexes 9-14 were synthesised in very high yields. The single-crystal X-ray structures of 12 and 13 confirm an asymmetric κ2-NO-μ-O arrangement in a dinuclear molecular disposition. These bimetallic aluminium complexes were investigated as catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide in the presence of ammonium salts. Under the optimal reaction conditions, complex 9 in combination with tetrabutylammonium bromide acts as a very efficient catalyst system for the conversion of both monosubstituted and internal epoxides into the corresponding cyclic carbonates showing broad substrate scope. Complex 9 and tetrabutylammonium bromide is the second most efficient aluminium-based catalyst system for the reaction of internal epoxides with carbon dioxide. A kinetic study has been carried out and showed that the reactions were first order in complex 9 and tetrabutylammonium bromide concentrations. Based on the kinetic study, a catalytic cycle is proposed.
Influence of the Counterion on the Synthesis of Cyclic Carbonates Catalyzed by Bifunctional Aluminum Complexes
Martínez, Javier,De La Cruz-Martínez, Felipe,Gaona, Miguel A.,Pinilla-Pealver, Esther,Fernández-Baeza, Juan,Rodríguez, Ana M.,Castro-Osma, José A.,Otero, Antonio,Lara-Sánchez, Agustín
, p. 3396 - 3408 (2019)
New bifunctional aluminum complexes have been prepared with the aim of studying the effect of a counterion on the synthesis of cyclic carbonates from epoxides and carbon dioxide (CO2). Neutral ligand 1 was used as a precursor to obtain four nov
Bifunctional Metal-Organic Layers for Tandem Catalytic Transformations Using Molecular Oxygen and Carbon Dioxide
Jiang, Xiaomin,Lan, Guangxu,Lin, Wenbin,Ni, Kaiyuan,Quan, Yangjian,Shi, Wenjie,Song, Yang,Wang, Cheng
supporting information, p. 16718 - 16724 (2021/10/21)
Tandem catalytic reactions improve atom- and step-economy over traditional synthesis but are limited by the incompatibility of the required catalysts. Herein, we report the design of bifunctional metal-organic layers (MOLs), HfOTf-Fe and HfOTf-Mn, consisting of triflate (OTf)-capped Hf6 secondary building units (SBUs) as strong Lewis acidic centers and metalated TPY ligands as metal active sites for tandem catalytic transformations using O2 and CO2 as coreactants. HfOTf-Fe effectively transforms hydrocarbons into cyanohydrins via tandem oxidation with O2 and silylcyanation whereas HfOTf-Mn converts styrenes into styrene carbonates via tandem epoxidation and CO2 insertion. Density functional theory calculations revealed the involvement of a high-spin FeIV (S = 2) center in the challenging oxidation of the sp3 C-H bond. This work highlights the potential of MOLs as a tunable platform to incorporate multiple catalysts for tandem transformations.
Intramolecular C(sp3)–H Bond Oxygenation by Transition-Metal Acylnitrenoids
Chen, Shuming,Hong, Yubiao,Houk, K. N.,Ivlev, Sergei,Meggers, Eric,Tan, Yuqi,Zhou, Zijun
, p. 21706 - 21710 (2020/10/02)
This study demonstrates for the first time that easily accessible transition-metal acylnitrenoids can be used for controlled direct C(sp3)-H oxygenations. Specifically, a ruthenium catalyst activates N-benzoyloxycarbamates as nitrene precursors towards regioselective intramolecular C?H oxygenations to provide cyclic carbonates, hydroxylated carbamates, or 1,2-diols. The method can be applied to the chemoselective C?H oxygenation of benzylic, allylic, and propargylic C(sp3)?H bonds. The reaction can be performed in an enantioselective fashion and switched in a catalyst-controlled fashion between C?H oxygenation and C?H amination. This work provides a new reaction mode for the regiocontrolled and stereocontrolled conversion of C(sp3)-H into C(sp3)?O bonds.
An in situ formed Ca2+-crown ether complex and its use in CO2-fixation reactions with terminal and internal epoxides
Steinbauer,Spannenberg,Werner
supporting information, p. 3769 - 3779 (2017/08/26)
Herein we report an efficient catalytic system based on readily available calcium iodide and 18-crown-6 ether for the atom economical addition of CO2 to epoxides. 1H NMR experiments revealed the selective in situ formation of a crown ether complex. This catalyst allows the conversion of various terminal epoxides under 1 atm CO2 pressure even at room temperature. Remarkably, a broad range of internal epoxides with various substitution patterns and substituents were smoothly converted which confirms the high efficiency and capability of the protocol. Notably, most of the internal carbonates were synthesized in high yields and diastereoselectivities of up to ≥99%. Furthermore, this system operates under solvent-free conditions without any co-catalysts e.g. onium salts.
