Cycloaddition Of Carbon Dioxide Research Articles

A Metal‐Free Synthesis of N‐Aryl Oxazolidin‐2‐Ones by the One‐Pot Reaction of Carbon Dioxide with N‐Aryl Aziridines

AbstractThe cost‐effective TPPH2/TBACl‐catalyzed (TPPH2=dianion of tetraphenyl porphyrin; TBACl=tetrabutyl ammonium chloride) carbon dioxide cycloaddition to N‐aryl aziridines was successful in synthesizing N‐aryl oxazolidin‐2‐ones. A catalytic tandem reaction was also developed, in which N‐aryl aziridines were initially synthesized and then reacted with carbon dioxide without being purified. The procedure occurred with a very high atom economy, molecular nitrogen being the only by‐product of the entire tandem process. In addition, the mechanism of catalytic cycle was investigated by DFT calculations.magnified image

SBA-15-Supported Imidazolium Ionic Liquid through Different Linkers as a Sustainable Catalyst for the Synthesis of Cyclic Carbonates: A Kinetic Study and Theoretical DFT Calculations

Various cyclic carbonates were prepared by cycloaddition of carbon dioxide with different epoxides using imidazolium-based catalysts grafted on a mesoporous silica support through 3-aminopropyltrim...

Visible-light-driven photocatalytic formation of propylene carbonate using FeNbO4/reduced graphene oxide composites

Photocatalytic cycloaddition of carbon dioxide to propylene oxide was achieved using a series of novel FeNbO4/reduced graphene oxide composites. Three different mass ratios of reduced graphene oxide incorporated FeNbO4 were used, namely, FeNbO4–3% rGO, FeNbO4–5% rGO, and FeNbO4–10% rGO. Prepared photocatalysts were characterized using UV–Visible (UV–Vis) diffuse reflectance spectroscopy (DRS), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Brunauer-Emmett-Teller (BET) for determination of the specific surface area and porosity. The successful incorporation of reduced graphene oxide into FeNbO4 was further supported with the enhanced photocatalytic performance of these composites, furthermore, FeNbO4–5% rGO exhibited the highest photocatalytic cyclic carbonate formation reaching up to 57% yield. Detailed investigation shows that the prepared composites are promising heterogeneous photocatalysts for the cycloaddition of carbon dioxide under simulated visible light irradiation, their enhanced photocatalytic activities ascribed to the enhanced separation efficiency of photo-generated charge carriers. To the best of our knowledge, this study is the first to report the preparation of FeNbO4/ reduced graphene oxide composites photocatalysts.

MIL-101(Cr) for CO2 Conversion into Cyclic Carbonates, Under Solvent and Co-Catalyst Free Mild Reaction Conditions

Mild reaction conditions (nearly room temperature and atmospheric CO2 pressure) for the cycloaddition of CO2 with epoxides to produce cyclic carbonates were investigated applying MIL-101(Cr) as a catalyst. The MIL-101 catalyst contains strong acid sites, which promote the ring-opening of the epoxide substrate. Moreover, the high surface area, enabling the adsorption of more CO2 (substrate), combined with a large pore size of the catalyst is essential for the catalytic performance. Additionally, epoxide substrates bearing electron-withdrawing substituents or having a low boiling point demonstrated an excellent conversion towards the cyclic carbonates. MIL-101(Cr) for the cycloaddition of carbon dioxide with epoxides is demonstrated to be a robust and stable catalyst able to be re-used at least five times without loss in activity.

Adenine-assisted synthesis of functionalized F-Mn-MOF-74 as an efficient catalyst with enhanced catalytic activity for the cycloaddition of carbon dioxide

The development of a highly efficient renewable heterogeneous catalysts for the synthesis of cyclic carbonates by the cyclic esterification of epoxides and carbon dioxide under relatively mild reaction conditions is of great significance in the territory of chemical fixation of carbon dioxide (CO2). This work comprises on a functional catalytic material F-Mn-MOF-74 using an effective competitive coordination strategy, adenine (Ad) as alkali source and competitive ligand, introduced onto the synthetic Mn-MOF-74. An F-Mn-MOF-74 crystal having a spherical structure and being functionalized is obtained, and lone pair of electrons on the nitrogen atom in the adenine can compete with 2,5-hydroxyterephthalic acid for coordination. The alkalinity exhibited by adenine is beneficial to enhance the catalytic properties of the crystal in the cycloaddition reaction of epoxide with carbon dioxide. Further catalytic experiments showed that the functionalized F-Mn-MOF-74 crystal combined with tetrabutylammonium bromide in the lacking of solvent showed excellent catalytic activity in the cycloaddition reaction of styrene oxide and carbon dioxide. Under the optimal reaction conditions after screening (100 °C and 10 bar CO2 pressure), the yield of cyclic carbonate was as high as 99 %. The excellent catalytic performance for other epoxides also confirmed that F-Mn-MOF-74 catalytic material is universal in its application. The catalytic performance of the catalyst was not significantly decreased after being recycled seven times, attributed to its excellent stability. The possible mechanism for the synergistic effect of Lewis acid-base properties of functionalized F-Mn-MOF-74 catalytic material with cocatalyst is also proposed.

Amine-oxide hybrid materials in combination with cobalt for the catalyzed cycloaddition of carbon dioxide and propylene oxide

Amine-oxide materials synthesized starting from small silica particles and porous silica in combination with polyethyleneimine have been prepared by co-condensation. The materials showing different surface areas and porosity were attained for M2 and M3 with low and high surface areas, respectively. In the new porous materials prepared CO2 adsorption capacity is enhanced at higher temperatures. The morphology of the resulting hybrid material influences the catalytic performance of salphenic cobalt catalysts in the CO2/propylene oxide coupling reactions. Depending on the catalytic reaction conditions (catalyst, cocatalyst, CO2 pressure and reaction temperature), high yields of the CO2/propylene oxide-cycloaddition reaction is favored over the copolymerization reaction.

Efficient Solvent-Free Synthesis of Cyclic Carbonates from the Cycloaddition of Carbon Dioxide and Epoxides Catalyzed by New Imidazolinium Functionalized Metal Complexes Under 0.1 MPa

A series of imidazolinium functionalized metal complexes were prepared as efficient and recyclable homogeneous catalysts for the synthesis of cyclic carbonates via the coupling reaction of carbon dioxide and epoxides in the absence of co-catalysts and solvent. Due to the synergistic effect between the metal center as Lewis acid and the imidazolinium groups with halide anions as Lewis base, these catalysts exhibited excellent catalytic capability. Particularly, high turnover frequency (TOF) values of (1174, 1240 and 1262 h−1) for bifunctional catalysts (2c, 2i and 2j, respectively) were achieved via adjusting reaction parameters. These catalysts also showed excellent catalytic performances under atmospheric pressure. Recyclability test showed that this kind of bifunctional catalyst can be easily recovered and reused for at least five times without dramatic loss of activity and selectivity. The optimum reaction conditions were also screened as (120 °C, 1.0 MPa CO2 and 2 h). The catalyst could also be applied to a variety of substrates and be used for a long time with high catalytic activities. We also performed the Kinetic studies, which suggested that the activity of catalysts following the order I− > Br− > Cl−. Moreover, a plausible reaction mechanism by imidazolinium functionalized metal complexes was proposed.

Mechanistic Insights into Cycloaddition of CO2 with Epoxide Catalyzed by a Bimetallic (Salen)Fe(II)Cl2 Complex with/without a Cocatalyst

AbstractThe cycloaddition of carbon dioxide (CO2) with propylene oxide (PO), with bimetallic (salen)Fe(II)Cl2 complex as the catalyst, was studied by using BP86/TZVP method. The calculated results revealed that the catalytic process exhibited a bimetallic cooperative mechanism, and a synergetic effect was observed between one Fe center and the axial ligand of chloride anion in the PO ring‐opening. The axial ligand of chloride anion acted as a cocatalyst. Moreover, a cocatalyst, i. e., NBu4Cl, has been introduced to the catalytic process. The catalytic process proceeded according to a monometallic mechanism, and chloride anion from NBu4Cl acted as a nucleophile in the PO ring‐opening. In addition, the energetic span model was applied to evaluate the catalytic efficiency of both catalytic systems. This current study provided novel insights into the molecular behavior of transition metal catalysts for the cycloaddition of CO2 with epoxides.

Supported Ruthenium and Tetrapropylammonium Bromide Catalysts for Oxidative Carboxylation of 1-Decene

Cyclic carbonate compounds are valuable for a range of applications and can be synthesized by a one-pot reaction involving epoxidation of olefin followed by reaction of the epoxide with CO2. This study used supported ruthenium catalysts for the epoxidation step (first step), where a combination of tetrapropylammonium bromide and zinc bromide was used for the cycloaddition of carbon dioxide. The supported ruthenium catalyst, prepared by a sol-immobilization method, allowed the effective epoxidation of 1-decene in air (using oxygen as the main oxidant) at 90 ºC in the presence of a catalytic quantity of radical initiator. This approach was applied to the one-pot multi-step oxidative carboxylation of 1-decene in the presence of 1 % Ru/support-Pr4NBr/ZnBr2 catalyst

Cycloaddition of Carbon Dioxide to Epoxides on a Hollow Zn–Co Based Zeolitic Imidazole Framework

Key words bimetallic catalysis - carbon dioxide - epoxides - cycloaddition - cyclic carbonates

CAU-11-COOH with a V-Shaped Linker as a Catalyst for the Solvent-Free Synthesis of Cyclic Carbonates from CO₂ and Epoxides.

An Al3+-based metal-organic framework (MOF), CAU-11-COOH, with a V-shaped ligand, DPSDA (3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride), was prepared using the solvothermal method, and was characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, elemental analysis, thermogravimetric analysis, Brunauer-Emmett-Teller analysis, and CO₂ adsorption. The catalytic efficiency of CAU-11-COOH was investigated in the solvent-free cycloaddition of carbon dioxide with epoxides, which yielded five-membered cyclic carbonates under mild reaction conditions. CAU-11-COOH with a co-catalyst, tetrabutylammonium bromide (TBAB), gave higher than 98% yield of epichlorohydrin carbonate at 80 °C without a solvent. A plausible reaction mechanism in which the Lewis acidic metal center, an uncoordinated carboxyl group, and a nucleophilic bromide anion operate synergistically is proposed. The CAU-11-COOH catalysts were found to exhibit high thermal stability and could be reused more than four times without any significant reduction in activity.

Solvent-Free cycloaddition of carbon dioxide and epichlorohydrin catalyzed by surface-attached imidazolium-type poly(ionic liquid) monolayers

Design and synthesis of effective catalysts for the conversion of epoxy compounds to cyclic carbonate under the presence of carbon dioxide molecules is essential for the utilization of carbon dioxide. Herein, we report that the surface-attached imidazolium-type poly(ionic liquid) bearing amine moieties is an efficient catalyst for the conversion of epoxy compound and carbon dioxide to cyclic carbonate. The effect of chemical structure of the synthesized catalyst and the reaction conditions on the catalytic efficiency is systematically studied. The results show that the catalyst with bromide anion can effectively catalyze the reaction under 1.5 MPa carbon dioxide pressure at 120 °C with the catalyst content of 10 mg mL−1, reaching the conversion rate up to 90 %. Moreover, the synthesized catalyst can be separated from the cyclic carbonate products by centrifugation. The recyclability and reversibility measurements reveal that the decay of the catalytic activity is mainly resulted from the adsorption of the cyclic carbonate products on the catalysts. The catalytic activity of the synthesized catalyst towards conversion of epichlorohydrin and carbon dioxide to cyclic carbonate can be recovered after extraction of the adsorbed cyclic carbonate products.

Ultrasound-assisted synthesis of a benzimidazole-containing Zn(II) coordination polymer as highly effective Lewis acid catalyst for cycloaddition of epoxides with CO2

A micron sized Zn (II) coordination polymer (CP), namely {[Zn(L)(5-mip)]·EtOH}(1) (L = 1,3-bis(benzimidazol-1-yl)-2-propanol and 5-H2mip = 5-methyisophthalic acid), was synthesized by ultrasonic irradiation at room temperature. The effects of ultrasonic power and time on the morphology and size of 1 were investigated in detail. Interestingly, micron sized 1 with considerable stability is can be used as an excellent and reused heterogeneous catalyst for carbon dioxide cycloaddition to epoxides under mild conditions.

Cobalt complexes containing salen-type pyridoxal ligand and DMSO for cycloaddition of carbon dioxide to propylene oxide

Cobalt complexes containing a salen-type pyridoxal ligand with pyridine were synthesized as a new Co(III) catalytic system for the cycloaddition of carbon dioxide. Two cobalt(III) complexes possessing a salen-type pyridoxyl ligand were synthesized by the reaction of pyridoxal ligands (pyr2en = (N,N′-bis(pyridoxylideneiminato)ethylene) and pyr2cy = (N,N′-bis(pyridoxylideneiminato)cyclohexane)) and Co(OAc)2 and characterized by various analytical methods, including infrared spectroscopy and high-resolution mass analysis. Single-crystal X-ray crystallography analysis confirmed that the cobalt pyr2en complex had a distorted octahedral structure: the tetradentate Schiff base ligand binds the cobalt metal in one plane, and the metal center adopts an octahedral geometry by the additional coordination of acetate and dimethyl sulfoxide. The synthesized complexes were used as catalysts in the cycloaddition of carbon dioxide (CO2) to propylene oxide. The catalysts showed high activity for cycloaddition between CO2 and epoxides, even at a low loading (0.5 mol%), in the presence of various cocatalysts.

Recent advances in the use of catalysts based on natural products for the conversion of CO2into cyclic carbonates

In this review we present a structured overview of the chemical catalytic systems containing any component derived from a natural product for the cycloaddition of carbon dioxide to epoxides to form cyclic carbonates.

A Stable Zn-Based Metal–Organic Framework as an Efficient Catalyst for Carbon Dioxide Cycloaddition and Alcoholysis at Mild Conditions

Developing highly efficient heterogeneous catalysts for cycloaddition of CO2 and epoxides to produce cyclic carbonates is promising but challenging. In this work, a novel three-dimensional metal organic framework (MOF) with cylinder pore systems and unsaturated Zn sites has been demonstrated as potent candidate in CO2 fixation at mild and solvent-free conditions. The Zn(atz)(bdc)0.5, where atz = aminotriazole and H2bdc = terephthalic, exhibits microporous nature that can regulate the catalytic interaction of active centers and substrates. The structure stability has been systematically investigated and proven to be sufficient for practical application. Furthermore, the cooperative effects of porosity, CO2 binding affinity, activation centers, and synergism with co-catalyst have been deeply investigated. Moreover, high propylene epoxide conversion (97%) and selectivity (> 99%) have been achieved at mild conditions (60 °C and 1 MPa) with excellent cycle stability. Owing to the well-defined pore system, an obvious substrates selectivity has been clearly observed. A possible catalytic mechanism has been proposed and verified by DFT calculations. Furthermore, the prepared Zn-MOF can also be used as an efficient heterogeneous catalyst for the reaction of epoxides with alcohols to produce β-alkoxy alcohol.

Benzothiophene-based complexes mediated formation of cyclic carbonates by cycloaddition of carbon dioxide to epoxides under mild solvent-free conditions

Transition metal complexes of the general formula [(S∩N∩N∩S)MCl2] (M: Cr(II), 2; Fe(II), 3, Co(II); 4; (S∩N∩N∩S): cis-1,2-N1,N2-bis{(benzo[b]thiophen-2-yl)methylene-diaminocyclohexane, S-DACH, 1) were prepared and characterized. The new complexes have been utilized as catalysts for the coupling reaction of carbon dioxide and the epoxides, styrene oxide (SO), and (±)-propylene oxide (PO), in the presence of bis(triphenylphosphoranylidene)imminium bromide (PPNBr) as a co-catalyst. The reactions were carried out under relatively low pressure and solvent-free conditions. The catalyst systems showed to be selective for the formation of cyclic carbonates. In general, the Cr(II)-based catalyst exhibited the highest activity for the coupling reaction of CO2 with both SO and (±)-PO compared with the corresponding iron(II) and cobalt(II) complexes under similar reaction conditions with turnover numbers values of 2445 and 1164 for the production of propylene carbonate and styrene carbonate, respectively.

Hydroxyl-functionalized pyrazolium ionic liquids to catalyze chemical fixation of CO2: Further benign reaction condition for the single-component catalyst

Lots of ionic liquids have been utilized as catalyst for the coupling reaction of carbon dioxide with epoxides, however, catalyzed conditions could not be regarded as benign, especially when no co-catalyst and/or organic solvent is involved. A series of hydroxyl-functionalized pyrazolium ionic liquids are firstly synthesized. They would efficiently catalyze the cycloaddition of carbon dioxide and propylene oxide under 110°C and 1.0MPa carbon dioxide initial pressure with 1mol% catalyst during 4h resulting in the product yield of 91.2%. The catalytic condition is greatly refined as compared with other single-component ionic liquids with simple anion. Simultaneously, the effect of reaction temperature, amount of catalyst, carbon dioxide initial pressure, and reaction time is explored along with the reusability of catalyst. For most of epoxides with terminal substituted group, HEEPzBr presents acceptable catalytic activity. The difference of HEMPzBr, HEEPzBr, and HPEPzBr is also explored by the density functional theory calculations.

Self‐Assembled Metalloporphyrins–Magnesium Phosphate Hybrid Spheres as Efficient Catalysts for Cycloaddition of Carbon Dioxide

AbstractDue to the unique microstructure and superior catalytic properties, organic‐inorganic hybrid materials attract extensive attention. Herein, we report a facile coprecipitation method for the fabrication of metalloporphyrin–metal phosphate salt hybrid spheres, and the cycloaddition of carbon dioxide with epoxides is employed as probe reaction to evaluate the catalytic performance of our as‐synthesized catalysts. The hybrid spheres composed of meso‐tetra‐(4‐N‐pyridyl) zinc porphyrin (ZnTPyP)–magnesium phosphate exhibited superior catalytic performance, and the conversion was much higher than that of individual ZnTPyP and magnesium phosphate, probably because of the acid‐base synergistic effect. Meanwhile, the spheres showed excellent stability during the circulation experiments as well as compatibility with a wide scope of substrates. This work provides a valuable approach for the preparation of novel and efficient heterogeneous catalytic composites.

2-Methylimidazole Modified Co-BTC MOF as an Efficient Catalyst for Chemical Fixation of Carbon Dioxide

[(CH3)2NH2][Co3(BTC)(HCOO)4(H2O)]·H2O (Co-BTC) was synthesized under solvothermal conditions, further used as the precursor for the synthesis of 2-methylimidazole modified Co-BTC (2MeIm@Co-BTC-x). The characteristics of 2MeIm@Co-BTC-x were systematically characterized by various technologies including XRD, FESEM, FT-IR, XPS, N2-adsorption, TG-DTG and CO2/NH3-TPD. It was found that except for the crystal faces (0 1 1) and (− 1 0 2) corresponding to ZIF-67 and Co-BTC, a new crystal phase appeared at 12.22o for the modified Co-BTC, which may be attributed to the coordination between 2MeIm and unsaturated Co ions of Co-BTC. Interestingly, a new structure of hexagonal prisms together with hierarchical porous were also formed for the modified Co-BTC. Besides, when this composite was explored as a heterogeneous catalyst for catalytic conversion of carbon dioxide with epichlorohydrin (ECH) as probe, an obvious enhancement in catalytic activity was obtained compared with the fresh Co-BTC, suggesting that 2MeIm ligands within the modified Co-BTC played a great role on the coupling process. Furthermore, 97.21% of ECH conversion and 98.79% of chloropropene carbonate selectivity were gained over 2MeIm@Co-BTC-1.0 under optimal conditions (3.0 MPa, 90 °C, 5 h, 0.75 wt% catalyst of ECH). Additionally, only a slight decrease in catalytic activity was found after the optimal sample was reused three times. Finally, a mechanism for interpreting the coupling process of carbon dioxide cycloaddition with epoxide was proposed. One-pot catalytic conversion of CO2 into cyclic carbonate over 2-methylimidazole modified Co-BTC