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Catalysts for a Green Chemistry: A Themed Issue Honoring Professor Roger Sheldon for His Contribution in the Field of the Green Chemistry with the Introduction of the E Factor

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Green Chemistry".

Deadline for manuscript submissions: closed (15 March 2021) | Viewed by 25053

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CSIC - Instituto de Catálisis y Petroleoquímica (ICP), Madrid, Spain
Interests: biocatalysis; CO2 transformation; redox processes; cofactor regeneration; enzyme immobilization
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Special Issue Information

Dear Colleagues,

Sheldon is distinguished for his pioneering and wide-ranging contributions to catalytic oxidation, biocatalysis, and green chemistry and for bridging the traditional gap between organic synthesis and catalysis. He introduced the concept of the E-factor, which is now used by companies globally for assessing the efficiency and environmental impact of chemical processes. He has consistently emphasized the need for a new paradigm in the evaluation of efficiency in chemical processes from the traditional concept of chemical yield to one that assigns value to waste minimization and is an avid proponent of elegance and precision in organic synthesis.

He received a Ph.D. in organic chemistry from the University of Leicester (UK) in 1967. After that, he migrated to the United States to take up a postdoctoral stay in the group of Jay Kochi at Case Western Reserve University in Cleveland and subsequently moved with Jay to Indiana University. He had more than 20 years industrial experience, as Vice President for Research and Development at DSM/Andeno from 1980 to 1990 and with Shell Research Amsterdam from 1969 to 1980. In 1991, he jointed to Delft University. He is also CEO of CLEA Technologies, a start-up biotech company.

Roger Sheldon is a recognized authority on Green Chemistry and Catalysis and Professor Emeritus of Biocatalysis and Organic Chemistry at Delft University of Technology. He is the author of several books on the subject of catalysis as well as 400 professional papers and >50 granted patents.

Sheldon was elected a Fellow of the Royal Society (FRS) in 2015 and a Fellow of the Royal Society of Chemistry (FRSC) in 1980. He was awarded the Green Chemistry Award by the Royal Society of Chemistry in 2010 and made an Honorary Fellow of the same society in 2018.

Molecules is highly pleased to host a Special Issue entitled “Catalysts for a Green Chemistry: A Themed Issue Honoring Professor Roger Sheldon for His Contribution in the Field of the Green Chemistry with the Introduction of the E Factor” honoring Prof. Roger A. Sheldon for his extensive and productive career and his special contribution introducing the E factor.

Prof. Dr. Cesar Mateo
Guest Editor

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Keywords

  • Green chemistry
  • Biocatalysis
  • Catalysis
  • E factor
  • Environmental processes
  • Organic synthesis
  • Enzymes
  • Redox reactions

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Published Papers (7 papers)

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Research

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15 pages, 2496 KiB  
Article
Chiral Imidazolium Prolinate Salts as Efficient Synzymatic Organocatalysts for the Asymmetric Aldol Reaction
by Raúl Porcar, Eduardo García-Verdugo, Belén Altava, Maria Isabel Burguete and Santiago V. Luis
Molecules 2021, 26(14), 4190; https://doi.org/10.3390/molecules26144190 - 9 Jul 2021
Cited by 3 | Viewed by 2695
Abstract
Chiral imidazolium l-prolinate salts, providing a complex network of supramolecular interaction in a chiral environment, have been studied as synzymatic catalytic systems. They are demonstrated to be green and efficient chiral organocatalysts for direct asymmetric aldol reactions at room temperature. The corresponding [...] Read more.
Chiral imidazolium l-prolinate salts, providing a complex network of supramolecular interaction in a chiral environment, have been studied as synzymatic catalytic systems. They are demonstrated to be green and efficient chiral organocatalysts for direct asymmetric aldol reactions at room temperature. The corresponding aldol products were obtained with moderate to good enantioselectivities. The influence of the presence of chirality in both the imidazolium cation and the prolinate anion on the transfer of chirality from the organocatalyst to the aldol product has been studied. Moreover, interesting match/mismatch situations have been observed regarding configuration of chirality of the two components through the analysis of results for organocatalysts derived from both enantiomers of prolinate (R/S) and the trans/cis isomers for the chiral fragment of the cation. This is associated with differences in the corresponding reaction rates but also to the different tendencies for the formation of aggregates, as evidenced by nonlinear effects studies (NLE). Excellent activities, selectivities, and enantioselectivities could be achieved by an appropriate selection of the structural elements at the cation and anion. Full article
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14 pages, 9540 KiB  
Article
Efficient One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones via a Three-Component Biginelli Reaction
by Giovanna Bosica, Fiona Cachia, Riccardo De Nittis and Nicole Mariotti
Molecules 2021, 26(12), 3753; https://doi.org/10.3390/molecules26123753 - 20 Jun 2021
Cited by 31 | Viewed by 4911
Abstract
Multicomponent reactions are considered to be of increasing importance as time progresses due to the economic and environmental advantages such strategies entail. The three-component Biginelli reaction involves the combination of an aldehyde, a β-ketoester and urea to produce 3,4-dihydropyrimidin-2(1H)-ones, also known [...] Read more.
Multicomponent reactions are considered to be of increasing importance as time progresses due to the economic and environmental advantages such strategies entail. The three-component Biginelli reaction involves the combination of an aldehyde, a β-ketoester and urea to produce 3,4-dihydropyrimidin-2(1H)-ones, also known as DHPMs. The synthesis of these products is highly important due to their myriad of medicinal properties, amongst them acting as calcium channel blockers and antihypertensive and anti-inflammatory agents. In this study, silicotungstic acid supported on Ambelyst-15 was used as a heterogeneous catalyst for the Biginelli reaction under solventless conditions. Electron-poor aromatic aldehydes gave the best results. Sterically hindered β-ketoesters resulted in lower reaction yields. The reaction was carried out under heterogeneous catalysis to allow easy recovery of the product from the reaction mixture and recycling of the catalyst. The heterogeneity of the reaction was confirmed by carrying out a hot filtration test. Full article
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12 pages, 2829 KiB  
Article
Geranyl Functionalized Materials for Site-Specific Co-Immobilization of Proteins
by Jana Brabcova, Alicia Andreu, David Aguilera, Zaida Cabrera, Blanca de las Rivas, Rosario Muñoz and Jose M. Palomo
Molecules 2021, 26(10), 3028; https://doi.org/10.3390/molecules26103028 - 19 May 2021
Viewed by 2531
Abstract
Different materials containing carboxylic groups have been functionalized with geranyl-amine molecules by using an EDC/NHS strategy. Chemical modification of the support was confirmed by XRD, UV-spectrophotometer, and FT-IR. This geranyl-functionalized material was successfully applied for four different strategies of site-selective immobilization of proteins [...] Read more.
Different materials containing carboxylic groups have been functionalized with geranyl-amine molecules by using an EDC/NHS strategy. Chemical modification of the support was confirmed by XRD, UV-spectrophotometer, and FT-IR. This geranyl-functionalized material was successfully applied for four different strategies of site-selective immobilization of proteins at room temperature and aqueous media. A reversible hydrophobic immobilization of proteins (lipases, phosphoglucosidases, or tyrosinase) was performed in neutral pH in yields from 40 to >99%. An increase of the activity in the case of lipases was observed from a range of 2 to 4 times with respect to the initial activity in solution. When chemically or genetically functionalized cysteine enzymes were used, the covalent immobilization, via a selective thiol-alkene reaction, was observed in the presence of geranyl support at pH 8 in lipases in the presence of detergent (to avoid the previous hydrophobic interactions). Covalent attachment was confirmed with no release of protein after immobilization by incubation with hydrophobic molecules. In the case of a selenium-containing enzyme produced by the selenomethionine pathway, the selective immobilization was successfully yielded at acidic pH (pH 5) (89%) much better than at pH 8. In addition, when an azido-enzyme was produced by the azide–homoalanine pathway, the selective immobilization was successful at pH 6 and in the presence of CuI for the click chemistry reaction. Full article
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17 pages, 1501 KiB  
Article
Catalytic Conversion of Xylose to Furfural by p-Toluenesulfonic Acid (pTSA) and Chlorides: Process Optimization and Kinetic Modeling
by Muhammad Sajid, Muhammad Rizwan Dilshad, Muhammad Saif Ur Rehman, Dehua Liu and Xuebing Zhao
Molecules 2021, 26(8), 2208; https://doi.org/10.3390/molecules26082208 - 12 Apr 2021
Cited by 25 | Viewed by 3124
Abstract
Furfural is one of the most promising precursor chemicals with an extended range of downstream derivatives. In this work, conversion of xylose to produce furfural was performed by employing p-toluenesulfonic acid (pTSA) as a catalyst in DMSO medium at moderate [...] Read more.
Furfural is one of the most promising precursor chemicals with an extended range of downstream derivatives. In this work, conversion of xylose to produce furfural was performed by employing p-toluenesulfonic acid (pTSA) as a catalyst in DMSO medium at moderate temperature and atmospheric pressure. The production process was optimized based on kinetic modeling of xylose conversion to furfural alongwith simultaneous formation of humin from xylose and furfural. The synergetic effects of organic acids and Lewis acids were investigated. Results showed that the catalyst pTSA-CrCl3·6H2O was a promising combined catalyst due to the high furfural yield (53.10%) at a moderate temperature of 120 °C. Observed kinetic modeling illustrated that the condensation of furfural in the DMSO solvent medium actually could be neglected. The established model was found to be satisfactory and could be well applied for process simulation and optimization with adequate accuracy. The estimated values of activation energies for xylose dehydration, condensation of xylose, and furfural to humin were 81.80, 66.50, and 93.02 kJ/mol, respectively. Full article
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10 pages, 1012 KiB  
Communication
Environmental Assessment of Enzyme Production and Purification
by Martin Becker, Stephan Lütz and Katrin Rosenthal
Molecules 2021, 26(3), 573; https://doi.org/10.3390/molecules26030573 - 22 Jan 2021
Cited by 16 | Viewed by 4483
Abstract
The importance of bioprocesses has increased in recent decades, as they are considered to be more sustainable than chemical processes in many cases. E factors can be used to assess the sustainability of processes. However, it is noticeable that the contribution of enzyme [...] Read more.
The importance of bioprocesses has increased in recent decades, as they are considered to be more sustainable than chemical processes in many cases. E factors can be used to assess the sustainability of processes. However, it is noticeable that the contribution of enzyme synthesis and purification is mostly neglected. We, therefore, determined the E factors for the production and purification of 10 g enzymes. The calculated complete E factor including required waste and water is 37,835 gwaste·genzyme−1. This result demonstrates that the contribution of enzyme production and purification should not be neglected for sustainability assessment of bioprocesses. Full article
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Review

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8 pages, 1387 KiB  
Review
Nitrile Synthesis with Aldoxime Dehydratases: A Biocatalytic Platform with Applications in Asymmetric Synthesis, Bulk Chemicals, and Biorefineries
by Pablo Domínguez de María
Molecules 2021, 26(15), 4466; https://doi.org/10.3390/molecules26154466 - 24 Jul 2021
Cited by 10 | Viewed by 3112
Abstract
Nitriles comprise a broad group of chemicals that are currently being industrially produced and used in fine chemicals and pharmaceuticals, as well as in bulk applications, polymer chemistry, solvents, etc. Aldoxime dehydratases catalyze the cyanide-free synthesis of nitriles starting from aldoximes under mild [...] Read more.
Nitriles comprise a broad group of chemicals that are currently being industrially produced and used in fine chemicals and pharmaceuticals, as well as in bulk applications, polymer chemistry, solvents, etc. Aldoxime dehydratases catalyze the cyanide-free synthesis of nitriles starting from aldoximes under mild conditions, holding potential to become sustainable alternatives for industrial processes. Different aldoxime dehydratases accept a broad range of aldoximes with impressive high substrate loadings of up to >1 Kg L−1 and can efficiently catalyze the reaction in aqueous media as well as in non-aqueous systems, such as organic solvents and solvent-free (neat substrates). This paper provides an overview of the recent developments in this field with emphasis on strategies that may be of relevance for industry and sustainability. When possible, potential links to biorefineries and to the use of biogenic raw materials are discussed. Full article
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23 pages, 6774 KiB  
Review
Microwaves as “Co-Catalysts” or as Substitute for Catalysts in Organophosphorus Chemistry
by György Keglevich
Molecules 2021, 26(4), 1196; https://doi.org/10.3390/molecules26041196 - 23 Feb 2021
Cited by 6 | Viewed by 2731
Abstract
The purpose of this review is to summarize the importance of microwave (MW) irradiation as a kind of catalyst in organophosphorus chemistry. Slow or reluctant reactions, such as the Diels-Alder cycloaddition or an inverse-Wittig type reaction, may be performed efficiently under MW irradiation. [...] Read more.
The purpose of this review is to summarize the importance of microwave (MW) irradiation as a kind of catalyst in organophosphorus chemistry. Slow or reluctant reactions, such as the Diels-Alder cycloaddition or an inverse-Wittig type reaction, may be performed efficiently under MW irradiation. The direct esterification of phosphinic and phosphonic acids, which is practically impossible on conventional heating, may be realized under MW conditions. Ionic liquid additives may promote further esterifications. The opposite reaction, the hydrolysis of P-esters, has also relevance among the MW-assisted transformations. A typical case is when the catalysts are substituted by MWs, which is exemplified by the reduction of phosphine oxides, and by the Kabachnik–Fields condensation affording α-aminophosphonic derivatives. Finally, the Hirao P–C coupling reaction may serve as an example, when the catalyst may be simplified under MW conditions. All of the examples discussed fulfill the expectations of green chemistry. Full article
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