Kinetics and mechanistic investigation of epoxide/CO2 cycloaddition by a synergistic catalytic effect of pyrrolidinopyridinium iodide and zinc halides

Rehman, Abdul; Eze, Valentine C.; Resul, M.F.M. Gunam; Harvey, Adam

doi:10.1016/j.jechem.2018.11.017

Cited by 39 publications

(29 citation statements)

References 75 publications

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“…This may be rationalized by a progressive dilution of the reaction mixture becoming increasingly CO 2 -rich while expanding the volume of the liquid phase. [60,67] From these combined observations we infer that the reaction between glycidol and CO 2 mediated by sodium citrate is most likely independent of the CO 2 concentration confirming the observations in Table 3. To determine the reaction order with respect to glycidol 1 a, propylene carbonate was selected as a polar solvent and the amount of glycidol was varied between 9 and 25 mmol while keeping the volume of the reaction constant under the standard reaction conditions mentioned above providing a nearly first order dependence on 1 a (Scheme 2b).…”

Section: Chemsuschemsupporting

confidence: 80%

“…The double logarithmic plot shown in Figure S28 {i. e., ln(k obs ) vs. ln[Na-citrate]} revealed a fractional reaction order of around 0.26 with respect to sodium citrate. [60,61] The apparent reaction rate in the same concentration range was also determined by in-situ infrared (IR) spectroscopy monitoring the increase of the carbonate stretching band of 1 b as described in previous contributions. [62][63][64] From these IR studies a fractional order of about 0.4 was obtained from the double logarithmic plot (Scheme 2b).…”

Section: Chemsuschemmentioning

confidence: 99%

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Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO₂ Pressure

et al. 2022

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Glycerol carbonate (GC) has emerged as an attractive synthetic target due to various promising technological applications. Among several viable strategies to produce GC from CO2 and glycerol and its derivatives, the cycloaddition of CO2 to glycidol represents an atom‐economic an efficient strategy that can proceed via a halide‐free manifold through a proton‐shuttling mechanism. Here, it was shown that the synthesis of GC can be promoted by bio‐based and readily available organic salts leading to quantitative GC formation under atmospheric CO2 pressure and moderate temperatures. Comparative and mechanistic experiments using sodium citrate as the most efficient catalyst highlighted the role of both hydrogen bond donor and weakly basic sites in the organic salt towards GC formation. The citrate salt was also used as a catalyst for the conversion of other epoxy alcohols. Importantly, the discovery that homogeneous organic salts catalyze the target reaction inspired us to use metal alginates as heterogeneous and recoverable bio‐based catalysts for the same process.

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Section: Chemsuschemsupporting

confidence: 80%

Section: Chemsuschemmentioning

confidence: 99%

Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO₂ Pressure

et al. 2022

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“…The kinetics of the cycloaddition reaction catalyzed by PP-Br-Zn-0.09 was investigated at 100 °C with propylene carbonate as a solvent. , The reaction orders of the CO 2 cycloaddition reaction with respect to ECH and CO 2 were 0.69 and 0.27 (Figure S8). This result indicated that the reaction rate of the cycloaddition reaction was more affected by the concentration of ECH than by the pressure of CO 2 .…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Bifunctional Porphyrin Polymers for Catalytic Conversion of Dilute CO₂ to Cyclic Carbonates

Liu

Jayakumar

Chen

et al. 2021

ACS Appl. Mater. Interfaces

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Development of efficient solid catalysts for catalytic conversion of dilute CO 2 is of extreme importance for carbon capture and utilization. We report the synthesis of bifunctional polymers co-incorporated with porphyrin-Zn as Lewis acid sites and Br − as nucleophiles for the cycloaddition of dilute CO 2 with epoxides in this work. It was found that the Br − /Zn ratio has a volcano relation with the activity of bifunctional polymers in a cycloaddition reaction, indicating the synergy effect between Lewis acid sites and nucleophiles. The turnover frequency (TOF) of the bifunctional polymer is more than four-fold that of the physical mixture of tetrabutylammonium bromide and porphyrin-Zn-incorporated polymer, implying the enhanced cooperation between Br − and porphyrin-Zn in the polymer network. The bifunctional polymer with optimized Br − /Zn afforded 99% conversion, 99% selectivity, and a TOF as high as 12,000 h −1 for the cycloaddition of CO 2 and propylene oxide, which is among the most active solid catalysts ever reported. Furthermore, the bifunctional polymer could efficiently catalyze the cycloaddition of epichlorohydrin with dilute CO 2 (7.5% CO 2 balanced by N 2 ) even under ambient conditions, demonstrating its potential application in industrial-scale production.

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“…At an optimal ratio of 1 /TBAB, the carbonate formation occurs preferentially via a well-known route showed in cycle 1 (Scheme ). The real contribution of this cycle to COC production gradually decreases when the TBAB concentration is raised, with cycle 2 being predominant in a large excess of bromides. , This results in a negative impact in the system because activation barriers are higher in cycle 2 than in cycle 1, since most catalyst molecules are inactive …”

Section: Resultsmentioning

confidence: 99%

Metal–Cocatalyst Interaction Governs the Catalytic Activity of M^II-Porphyrazines for Chemical Fixation of CO₂

et al. 2021

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Chemical fixation of CO 2 to produce cyclic carbonates can be a green and atomic efficient process. In this work, a series of porphyrazines (Pzs) containing electronwithdrawing groups and central M II ions (where M = Mg, Zn, Cu, and Co) were synthesized and investigated as catalysts for the cycloaddition of CO 2 to epoxides. Then, the efficiency of the Pzs was tested by varying cocatalyst type and concentration, epoxide, temperature, and pressure. Mg II Pz bearing trifluoromethyl groups (1) showed the best conversion, producing, selectively, 78% of propylene cyclic carbonate (PCC), indicating that a harder and stronger Lewis acid is more effective for epoxide activation. Moreover, cocatalyst variation showed a notable effect on the reaction yields. Spectrophotometric titrations, MALDI-TOF mass spectra, and theoretical calculations suggest poisoning of the catalyst when tetrabutylammonium chloride (TBAC) and large amounts of tetrabutylammonium bromide (TBAB) were used in the system. The same was not observed for tetrabutylammonium iodide (TBAI), indicating that the metal−cocatalyst interaction may govern the reaction rate. In addition, two rare examples of crystalline structures were obtained, proving the distorted square pyramidal geometry with water molecule as axial ligand. This is one of the first studies reporting Pzs as catalysts for the chemical fixation of CO 2 , and we believe that the intricate balance between cocatalyst concentration and conversion efficiency shown here may aid future studies in the area.

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Kinetics and mechanistic investigation of epoxide/CO2 cycloaddition by a synergistic catalytic effect of pyrrolidinopyridinium iodide and zinc halides

Cited by 39 publications

References 75 publications

Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO₂ Pressure

Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO₂ Pressure

Synthesis of Bifunctional Porphyrin Polymers for Catalytic Conversion of Dilute CO₂ to Cyclic Carbonates

Metal–Cocatalyst Interaction Governs the Catalytic Activity of M^II-Porphyrazines for Chemical Fixation of CO₂

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Kinetics and mechanistic investigation of epoxide/CO2 cycloaddition by a synergistic catalytic effect of pyrrolidinopyridinium iodide and zinc halides

Cited by 39 publications

References 75 publications

Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO2 Pressure

Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO2 Pressure

Synthesis of Bifunctional Porphyrin Polymers for Catalytic Conversion of Dilute CO2 to Cyclic Carbonates

Metal–Cocatalyst Interaction Governs the Catalytic Activity of MII-Porphyrazines for Chemical Fixation of CO2

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Product

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Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO₂ Pressure

Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO₂ Pressure

Synthesis of Bifunctional Porphyrin Polymers for Catalytic Conversion of Dilute CO₂ to Cyclic Carbonates

Metal–Cocatalyst Interaction Governs the Catalytic Activity of M^II-Porphyrazines for Chemical Fixation of CO₂