Scalable and Selective Preparation of 3,3′,5,5′-Tetramethyl-2,2′-biphenol

Quell, Thomas; Hecken, Nadine; Dyballa, Katrin M.; Franke, Robert; Waldvogel, Siegfried R.

doi:10.1021/acs.oprd.6b00356

Cited by 4 publications

(5 citation statements)

References 43 publications

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“…The reaction calorimetry was evaluated using a Mettler Toledo EasyMax 102 HF Cal . The initial reaction calorimetry evaluations involved the Suzuki–Miyaura cross-coupling of 1-bromo-3-(trifluoromethyl)benzene with potassium vinyltrifluoroborate.…”

Section: Results and Discussionmentioning

confidence: 99%

Evaluation of Potential Safety Hazards Associated with the Suzuki–Miyaura Cross-Coupling of Aryl Bromides with Vinylboron Species

Canturk¹,

Gray²,

McCusker³

et al. 2018

Org. Process Res. Dev.

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The potential safety hazards associated with the Suzuki–Miyaura cross-coupling of aryl bromides with vinylboron species were evaluated. In the Suzuki–Miyaura cross-coupling of 1-bromo-3-(trifluoromethyl)benzene with potassium vinyltrifluoroborate in the presence of potassium carbonate (K2CO3) in 9:1 dimethyl sulfoxide (DMSO)/water at 80 °C, the thermal profile revealed a significant exotherm upon the addition of catalytic 1,1′-bis(diphenylphosphino)ferrocene palladium(II) dichloride [Pd(dppf)Cl2]. Further investigations indicated that the exotherm was consistently higher and the reactions were faster in the studied aqueous systems compared to anhydrous conditions. Although under anhydrous conditions the exotherms were comparable among the studied cases, the rate of the exotherm was highly dependent on the choice of aryl electrophile, solvent, base, catalyst, as well as vinylboron species. In many of the studied cases the maximum temperature of a synthesis reaction (MTSR) was considerably higher than the boiling point of the solvent and/or the onset temperature of the DMSO decomposition, indicating that in the absence of active cooling the system could quickly exceed the boiling point of the solvent or trigger the decomposition of the reaction mixture to result in a runaway reaction.

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Section: Results and Discussionmentioning

confidence: 99%

Evaluation of Potential Safety Hazards Associated with the Suzuki–Miyaura Cross-Coupling of Aryl Bromides with Vinylboron Species

Canturk¹,

Gray²,

McCusker³

et al. 2018

Org. Process Res. Dev.

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“…Reaction calorimetry was evaluated using a Mettler-Toledo EasyMax 102 reaction system with an HFCal heat flow calorimeter. , All of the reactions were performed at a stirring rate of 400 rpm under a nitrogen blanket using either procedure A or procedure B. The exothermic event was integrated to determine Δ H , which was then used for the calculation of Δ T ad and the MTSR.…”

Section: Experimental Sectionmentioning

confidence: 99%

Safety Evaluation of the Copper-Mediated Cross-Coupling of 2-Bromopyridines with Ethyl Bromodifluoroacetate

Cabrera¹,

Li²,

Sheng

et al. 2018

Org. Process Res. Dev.

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The potential safety hazards associated with the copper-mediated cross-coupling of 2-bromopyridines with ethyl bromodifluoroacetate were evaluated. Thermal stability evaluation of the postreaction mixture of 50.6 mmol of 2-bromopyridine with 1.3 equiv of ethyl bromodifluoroacetate in the presence of 2.1 equiv of copper in 40 mL of dimethyl sulfoxide (DMSO) indicated a significant decomposition event with an onset temperature of 115.5 °C by accelerating rate calorimetry, which was significantly lower than that of neat DMSO. In contrast, the reaction mixture in N,N-dimethylformamide did not show any exothermic decomposition up to 400 °C by differential scanning calorimetry. Reaction calorimetry evaluation of this reaction in DMSO revealed a heat output (ΔH) of −13.5 kJ and an adiabatic temperature rise (ΔT ad ) of 129.5 °C, resulting in a maximum temperature of a synthesis reaction (MTSR) of 189.5 °C. The predicted heat of reaction using density functional theory with the BLYP functional was in good agreement with the experimental data. The scope studies with a variety of substituted 2bromopyridines revealed similar magnitudes of ΔH and ΔT ad compared to 2-bromopyridine when reacted at the same concentration. In all of the studied cases, the MTSR was significantly higher than the onset temperature of reaction mixture decomposition, indicating that in the absence of active cooling the system could quickly trigger the decomposition of the reaction mixture, resulting in a runaway reaction.

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“…The oxidative coupling of phenols is an attractive synthetic route leading to primary components of natural organic products, drugs, and ligands . The homo- and cross-coupling of phenols results in several essential products of significant biological activities.…”

Section: Introductionmentioning

confidence: 99%

“…The electro-oxidation of phenols has gained attention as a greener alternative to stoichiometric oxidative reactions as it eliminates the use of several environmentally toxic stoichiometric reagents. , When elevated temperature and dedicated electrode materials were used, the yield and selectivity of this process have been upgraded with selectivity reaching 70%, although at the expense of the use of expensive and harmful additives or elevated temperatures. Therefore, combining MIPs providing selectivity with electrosynthesis affording controlled oxidation of phenol compounds can be a prospective solution for the above-mentioned challenges.…”

Section: Introductionmentioning

confidence: 99%

“…The oxidative coupling of phenols is an attractive synthetic route leading to primary components of natural organic products, drugs, and ligands. 25 The homo- and cross-coupling of phenols results in several essential products of significant biological activities. 2,2′-Biphenol is a fascinating compound forming the backbone of several ligand systems applied in catalysis involving transition metals.…”

Section: Introductionmentioning

confidence: 99%

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Improving the Selectivity of the C–C Coupled Product Electrosynthesis by Using Molecularly Imprinted Polymer─An Enhanced Route from Phenol to Biphenol

Sudagar,

Shao,

Żołek

et al. 2023

ACS Appl. Mater. Interfaces

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We developed a procedure for selective 2,4dimethylphenol, DMPh, direct electro-oxidation to 3,3′,5,5′tetramethyl-2,2′-biphenol, TMBh, a C−C coupled product. For that, we used an electrode coated with a product-selective molecularly imprinted polymer (MIP). The procedure is reasonably selective toward TMBh without requiring harmful additives or elevated temperatures. The TMBh product itself was used as a template for imprinting. We followed the template interaction with various functional monomers (FMs) using density functional theory (DFT) simulations to select optimal FM. On this basis, we used a prepolymerization complex of TMBh with carboxyl-containing FM at a 1:2 TMBh-to-FM molar ratio for MIP fabrication. The template−FM interaction was also followed by using different spectroscopic techniques. Then, we prepared the MIP on the electrode surface in the form of a thin film by the potentiodynamic electropolymerization of the chosen complex and extracted the template. Afterward, we characterized the fabricated films by using electrochemistry, FTIR spectroscopy, and AFM, elucidating their composition and morphology. Ultimately, the DMPh electro-oxidation was performed on the MIP film-coated electrode to obtain the desired TMBh product. The electrosynthesis selectivity was much higher at the electrode coated with MIP film in comparison with the reference nonimprinted polymer (NIP) film-coated or bare electrodes, reaching 39% under optimized conditions. MIP film thickness and electrosynthesis parameters significantly affected the electrosynthesis yield and selectivity. At thicker films, the yield was higher at the expense of selectivity, while the electrosynthesis potential increase enhanced the TMBh product yield. Computer simulations of the imprinted cavity interaction with the substrate molecule demonstrated that the MIP cavity promoted direct coupling of the substrate to form the desired TMBh product.

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Scalable and Selective Preparation of 3,3′,5,5′-Tetramethyl-2,2′-biphenol

Cited by 4 publications

References 43 publications

Evaluation of Potential Safety Hazards Associated with the Suzuki–Miyaura Cross-Coupling of Aryl Bromides with Vinylboron Species

Evaluation of Potential Safety Hazards Associated with the Suzuki–Miyaura Cross-Coupling of Aryl Bromides with Vinylboron Species

Safety Evaluation of the Copper-Mediated Cross-Coupling of 2-Bromopyridines with Ethyl Bromodifluoroacetate

Improving the Selectivity of the C–C Coupled Product Electrosynthesis by Using Molecularly Imprinted Polymer─An Enhanced Route from Phenol to Biphenol

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