James Sherwood | University of York (original) (raw)

Papers by James Sherwood

Journal of Chemical Education

A laboratory experiment was developed to introduce systems thinking and green chemistry concepts ... more A laboratory experiment was developed to introduce systems thinking and green chemistry concepts through the synthesis of the antidepressant and smoking cessation aid, bupropion hydrochloride. The traditional synthesis has several issues from a green chemistry perspective: it uses the toxic solvents N-methylpyrrolidinone (NMP) and dichloromethane (DCM) and other hazardous chemicals including bromine and 12 M hydrochloric acid resulting in 138 kg of waste per kg of product. A greener synthesis has been developed with suitable improvements to the traditional procedure. The reprotoxic NMP and potentially carcinogenic DCM solvents have been substituted with the green biobased solvent Cyrene and ethyl acetate, respectively, and bromine has been substituted with N-bromosuccinimide. An alternate extraction method has also been developed using 1 M hydrochloric acid and ethyl acetate rather than 12 M hydrochloric acid and diethyl ether. These changes have also reduced waste by 92 kg kg −1 , and the resultant experiment is much safer to perform. As part of this laboratory experiment, students synthesize bupropion hydrochloride, and the adaptations to the traditional process are discussed and evaluated. Students are also introduced to the green metrics of atom economy, process mass intensity, and E-factor, which they use to quantify the greenness of the original and adapted procedures.

European Journal of Organic Chemistry

In this work, a new metric called 'Service-weighted Product Level Absolute Sustainability' is pro... more In this work, a new metric called 'Service-weighted Product Level Absolute Sustainability' is proposed as a numerical indicator to determine if a product is sustainable. The service offered by a product was found to be crucial to normalize its environmental impact and permit comparisons between products. Service-weighted Product Level Absolute Sustainability is demonstrated here with examples of water use for laundry and food production. The maximum justifiable environmental impact of these products has been calculated based on their performance, i.e., the quantity of clothes washed or nutritional content. Now the environmental impact of products can be rationalized as either sustainable or unsustainable, informing sustainable choices by manufacturers as well as consumers.

Abstract: The global bio-based chemical market is growing in size and importance. Bio-based solve... more Abstract: The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids) will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents.

Molecules, 2020

It is a pleasure to write this editorial highlighting some of the recent papers discussing solven... more It is a pleasure to write this editorial highlighting some of the recent papers discussing solvents in the Green Chemistry section of Molecules [...].

This paper defi nes, introduces and applies a new term, the “Biomass Utilization Effi ciency (BUE... more This paper defi nes, introduces and applies a new term, the “Biomass Utilization Effi ciency (BUE)”. This is a new and relatively simple approach to evaluate and compare different bio-based chemicals, materials and fuels based on the input-biomass, the used conversion process and the end product. A BUE analysis can answer the following questions: How effi ciently is biomass utilized? What share of the biomass is ending up in the fi nal product? To summarise the role of the Biomass utilization effi ciency (BUE) in the context of existing methods, it is obvious that this new metric has an emphasis on the best combination of biomass feedstock, process and bio-based product that is absent from existing calculations routinely used by research and process chemists and engineers. At present, waste minimisation during a manufacturing process is addressed through the choice of methods and optimisation of conditions. However, it is now clear that inherent waste, produced by aerobic fermentati...

Reaction Chemistry & Engineering, 2020

Direct comparison of safer dipolar aprotic solvents for use in carbon–carbon bond formation is of... more Direct comparison of safer dipolar aprotic solvents for use in carbon–carbon bond formation is of vital importance for industrial applications. Cyrene exhibited high initial reaction rates, yields and solvent recovery in the Baylis–Hillman reaction.

Beilstein Journal of Organic Chemistry, 2020

The development and study of new solvents has become important due to a proliferation of regulati... more The development and study of new solvents has become important due to a proliferation of regulations preventing or limiting the use of many conventional solvents. In this work, the suitability of the Suzuki–Miyaura reaction to demonstrate the usefulness of new solvents was evaluated, including Cyrene™, dimethyl isosorbide, ethyl lactate, 2-methyltetrahydrofuran (2-MeTHF), propylene carbonate, and γ-valerolactone (GVL). It was found that the cross coupling is often unaffected by the choice of solvent, and therefore the Suzuki–Miyaura reaction provides limited information regarding the usefulness of any particular solvent for organic synthesis.

Bioresource Technology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Johnson Matthey Technology Review, 2019

Recycling of plastic is an established technology contributing to a circular economy. A sustainab... more Recycling of plastic is an established technology contributing to a circular economy. A sustainable society requires recycling to produce high quality feedstocks from all types of reusable waste. New recycling technologies will help to improve waste management practices, for instance dissolving plastic waste in a solvent to purify and maintain its material properties. In solution it is also possible to depolymerise polymers into monomers that can be used to remake virgin-grade material. In this review the advantages and disadvantages of three solvent-based recycling processes will be considered: separation of cotton and polyester (polyethylene terephthalate (PET)) textiles, chemical recycling of polylactic acid (PLA) and dissolution-precipitation of polyvinylchloride (PVC). The current state of the art and future prospects are discussed, including a brief overview of how solvents are being used to process other types of plastic waste.

Molecules, 2019

There is demand for safer and bio-based solvents, brought on by legislation and sustainability ob... more There is demand for safer and bio-based solvents, brought on by legislation and sustainability objectives. The prediction of physical properties is highly desirable to help design new molecules. Here we present an in silico approach to obtain calculated Kamlet–Abboud–Taft solvatochromic parameters using virtual experiments. The tautomerisation equilibrium of methyl acetoacetate and dimedone was calculated in different solvents with COSMO-RS theory and converted into estimates of solvent dipolarity and hydrogen bond accepting ability, respectively. Hydrogen bond donating ability was calculated as a function of the electron deficient surface area on protic solvents. These polarity descriptors correlate with rate constants and equilibria, and so ability of calculated Kamlet–Abboud–Taft solvatochromic parameters to recreate experimental free energy relationships was tested with sixteen case studies taken from the literature. The accuracy of the calculated parameters was also satisfactor...

Green Chemistry, 2019

A review of the solvent effects that control the productivity of cross-coupling reactions, and su... more A review of the solvent effects that control the productivity of cross-coupling reactions, and suggested safer alternative solvents.

ACS Sustainable Chemistry & Engineering, 2018

Angewandte Chemie International Edition, 2018

Green Chemistry, 2018

Propylene carbonate and γ-valerolactone prevent transformation of Sn4+(aq) into inactive SnO2(s),... more Propylene carbonate and γ-valerolactone prevent transformation of Sn4+(aq) into inactive SnO2(s), maintaining active Lewis acidity for glucose-to-fructose isomerisation.

Bioresource Technology, 2017

Valorisation of bread waste for hydroxymethylfurfural (HMF) synthesis was examined in dimethyl su... more Valorisation of bread waste for hydroxymethylfurfural (HMF) synthesis was examined in dimethyl sulfoxide (DMSO)-, tetrahydrofuran (THF)-, acetonitrile (ACN)-, and acetonewater (1:1 v/v), under heating at 140 o C with SnCl 4 as the catalyst. The overall rate of the process was the fastest in ACN/H 2 O and acetone/H 2 O, followed by DMSO/H 2 O and THF/H 2 O due to the rate-limiting glucose isomerisation. However, the formation of levulinic acid (via rehydration) and humins (via polymerisation) was more significant in ACN/H 2 O and acetone/H 2 O. The constant HMF maxima (26-27 mol%) in ACN/H 2 O, acetone/H 2 O, and DMSO/H 2 O indicated that the rates of desirable reactions (starch hydrolysis, glucose isomerisation, and fructose dehydration) relative to undesirable pathways (HMF rehydration and polymerisation) were comparable among these mediums. They also demonstrated higher selectivity towards HMF production over the side reactions than THF/H 2 O. This study differentiated the effects of polar aprotic solvent-water mediums on simultaneous pathways during biomass conversion.

Journal of Chemical Education

A laboratory experiment was developed to introduce systems thinking and green chemistry concepts ... more A laboratory experiment was developed to introduce systems thinking and green chemistry concepts through the synthesis of the antidepressant and smoking cessation aid, bupropion hydrochloride. The traditional synthesis has several issues from a green chemistry perspective: it uses the toxic solvents N-methylpyrrolidinone (NMP) and dichloromethane (DCM) and other hazardous chemicals including bromine and 12 M hydrochloric acid resulting in 138 kg of waste per kg of product. A greener synthesis has been developed with suitable improvements to the traditional procedure. The reprotoxic NMP and potentially carcinogenic DCM solvents have been substituted with the green biobased solvent Cyrene and ethyl acetate, respectively, and bromine has been substituted with N-bromosuccinimide. An alternate extraction method has also been developed using 1 M hydrochloric acid and ethyl acetate rather than 12 M hydrochloric acid and diethyl ether. These changes have also reduced waste by 92 kg kg −1 , and the resultant experiment is much safer to perform. As part of this laboratory experiment, students synthesize bupropion hydrochloride, and the adaptations to the traditional process are discussed and evaluated. Students are also introduced to the green metrics of atom economy, process mass intensity, and E-factor, which they use to quantify the greenness of the original and adapted procedures.

European Journal of Organic Chemistry

In this work, a new metric called 'Service-weighted Product Level Absolute Sustainability' is pro... more In this work, a new metric called 'Service-weighted Product Level Absolute Sustainability' is proposed as a numerical indicator to determine if a product is sustainable. The service offered by a product was found to be crucial to normalize its environmental impact and permit comparisons between products. Service-weighted Product Level Absolute Sustainability is demonstrated here with examples of water use for laundry and food production. The maximum justifiable environmental impact of these products has been calculated based on their performance, i.e., the quantity of clothes washed or nutritional content. Now the environmental impact of products can be rationalized as either sustainable or unsustainable, informing sustainable choices by manufacturers as well as consumers.

Abstract: The global bio-based chemical market is growing in size and importance. Bio-based solve... more Abstract: The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids) will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents.

Molecules, 2020

It is a pleasure to write this editorial highlighting some of the recent papers discussing solven... more It is a pleasure to write this editorial highlighting some of the recent papers discussing solvents in the Green Chemistry section of Molecules [...].

This paper defi nes, introduces and applies a new term, the “Biomass Utilization Effi ciency (BUE... more This paper defi nes, introduces and applies a new term, the “Biomass Utilization Effi ciency (BUE)”. This is a new and relatively simple approach to evaluate and compare different bio-based chemicals, materials and fuels based on the input-biomass, the used conversion process and the end product. A BUE analysis can answer the following questions: How effi ciently is biomass utilized? What share of the biomass is ending up in the fi nal product? To summarise the role of the Biomass utilization effi ciency (BUE) in the context of existing methods, it is obvious that this new metric has an emphasis on the best combination of biomass feedstock, process and bio-based product that is absent from existing calculations routinely used by research and process chemists and engineers. At present, waste minimisation during a manufacturing process is addressed through the choice of methods and optimisation of conditions. However, it is now clear that inherent waste, produced by aerobic fermentati...

Reaction Chemistry & Engineering, 2020

Direct comparison of safer dipolar aprotic solvents for use in carbon–carbon bond formation is of... more Direct comparison of safer dipolar aprotic solvents for use in carbon–carbon bond formation is of vital importance for industrial applications. Cyrene exhibited high initial reaction rates, yields and solvent recovery in the Baylis–Hillman reaction.

Beilstein Journal of Organic Chemistry, 2020

The development and study of new solvents has become important due to a proliferation of regulati... more The development and study of new solvents has become important due to a proliferation of regulations preventing or limiting the use of many conventional solvents. In this work, the suitability of the Suzuki–Miyaura reaction to demonstrate the usefulness of new solvents was evaluated, including Cyrene™, dimethyl isosorbide, ethyl lactate, 2-methyltetrahydrofuran (2-MeTHF), propylene carbonate, and γ-valerolactone (GVL). It was found that the cross coupling is often unaffected by the choice of solvent, and therefore the Suzuki–Miyaura reaction provides limited information regarding the usefulness of any particular solvent for organic synthesis.

Bioresource Technology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Johnson Matthey Technology Review, 2019

Recycling of plastic is an established technology contributing to a circular economy. A sustainab... more Recycling of plastic is an established technology contributing to a circular economy. A sustainable society requires recycling to produce high quality feedstocks from all types of reusable waste. New recycling technologies will help to improve waste management practices, for instance dissolving plastic waste in a solvent to purify and maintain its material properties. In solution it is also possible to depolymerise polymers into monomers that can be used to remake virgin-grade material. In this review the advantages and disadvantages of three solvent-based recycling processes will be considered: separation of cotton and polyester (polyethylene terephthalate (PET)) textiles, chemical recycling of polylactic acid (PLA) and dissolution-precipitation of polyvinylchloride (PVC). The current state of the art and future prospects are discussed, including a brief overview of how solvents are being used to process other types of plastic waste.

Molecules, 2019

There is demand for safer and bio-based solvents, brought on by legislation and sustainability ob... more There is demand for safer and bio-based solvents, brought on by legislation and sustainability objectives. The prediction of physical properties is highly desirable to help design new molecules. Here we present an in silico approach to obtain calculated Kamlet–Abboud–Taft solvatochromic parameters using virtual experiments. The tautomerisation equilibrium of methyl acetoacetate and dimedone was calculated in different solvents with COSMO-RS theory and converted into estimates of solvent dipolarity and hydrogen bond accepting ability, respectively. Hydrogen bond donating ability was calculated as a function of the electron deficient surface area on protic solvents. These polarity descriptors correlate with rate constants and equilibria, and so ability of calculated Kamlet–Abboud–Taft solvatochromic parameters to recreate experimental free energy relationships was tested with sixteen case studies taken from the literature. The accuracy of the calculated parameters was also satisfactor...

Green Chemistry, 2019

A review of the solvent effects that control the productivity of cross-coupling reactions, and su... more A review of the solvent effects that control the productivity of cross-coupling reactions, and suggested safer alternative solvents.

ACS Sustainable Chemistry & Engineering, 2018

Angewandte Chemie International Edition, 2018

Green Chemistry, 2018

Propylene carbonate and γ-valerolactone prevent transformation of Sn4+(aq) into inactive SnO2(s),... more Propylene carbonate and γ-valerolactone prevent transformation of Sn4+(aq) into inactive SnO2(s), maintaining active Lewis acidity for glucose-to-fructose isomerisation.

Bioresource Technology, 2017

Valorisation of bread waste for hydroxymethylfurfural (HMF) synthesis was examined in dimethyl su... more Valorisation of bread waste for hydroxymethylfurfural (HMF) synthesis was examined in dimethyl sulfoxide (DMSO)-, tetrahydrofuran (THF)-, acetonitrile (ACN)-, and acetonewater (1:1 v/v), under heating at 140 o C with SnCl 4 as the catalyst. The overall rate of the process was the fastest in ACN/H 2 O and acetone/H 2 O, followed by DMSO/H 2 O and THF/H 2 O due to the rate-limiting glucose isomerisation. However, the formation of levulinic acid (via rehydration) and humins (via polymerisation) was more significant in ACN/H 2 O and acetone/H 2 O. The constant HMF maxima (26-27 mol%) in ACN/H 2 O, acetone/H 2 O, and DMSO/H 2 O indicated that the rates of desirable reactions (starch hydrolysis, glucose isomerisation, and fructose dehydration) relative to undesirable pathways (HMF rehydration and polymerisation) were comparable among these mediums. They also demonstrated higher selectivity towards HMF production over the side reactions than THF/H 2 O. This study differentiated the effects of polar aprotic solvent-water mediums on simultaneous pathways during biomass conversion.