François Jérôme

Glycerol as a sustainable solvent for green chemistry

Glycerol, an organic waste generated by the biodiesel industry, has been recently proposed as a valuable green solvent. This review summarizes the advantages, disadvantages and potential uses of glycerol as a green solvent for catalysis, organic synthesis, separations and materials chemistry. In particular, through selected examples we show here that glycerol may combine the advantages of water (low toxicity, low price, large availability, renewability) and ionic liquids (high boiling point, low vapour pressure, low solubility in scCO2). More generally, all these reported works contribute to increase the portfolio of available green solvents and afford innovative solutions to the substitution of the conventionally used volatile organic solvents.

Bio-based solvents: an emerging generation of fluids for the design of eco-efficient processes in catalysis and organic chemistry.

Biomass and waste exhibit great potential for replacing fossil resources in the production of chemicals. The search for alternative reaction media to replace petroleum-based solvents commonly used in chemical processes is an important objective of significant environmental consequence. Recently, bio-based derivatives have been either used entirely as green solvents or utilized as pivotal ingredients for the production of innovative solvents potentially less toxic and more bio-compatible. This review presents the background and classification of these new media and highlights recent advances in their use in various areas including organic synthesis, catalysis, biotransformation and separation. The greenness, advantages and limitations of these solvents are also discussed.

Rational design of solid catalysts for the selective use of glycerol as a natural organic building block.

Glycerol is the main co-product of the vegetable oils industry (especially biodiesel). With the rapid development of oleochemistry, the production of glycerol is rapidly increasing and chemists are trying to find new applications of glycerol to encourage a better industrial development of vegetable oils. In this Review, attention is focused on the selective use of glycerol as a safe organic building block for organic chemistry. An overview is given of the different heterogeneous catalytic routes developed by chemists for the successful and environmentally friendly use of glycerol in sustainable organic chemistry. In particular, the effects of different catalyst structural parameters are discussed to clearly highlight how catalysis can help organic chemists to overcome the drawbacks stemming from the use of glycerol as a safe organic building block. It is shown that heterogeneous catalysis offers efficient routes for bypassing the traditional use of highly toxic and expensive epichlorohydrin, 3-chloro-1,2-propanediol, or glycidol, which are usually used as a glyceryl donor in organic chemistry.

Heterogeneously catalyzed etherification of glycerol: new pathways for transformation of glycerol to more valuable chemicals

Direct etherification of glycerol with alkyl alcohols, olefins and dibenzyl ethers was successfully catalyzed by acid functionalized silica, allowing the first catalytic access to valuable monoalkyl glyceryl ethers.

Conversion of fructose and inulin to 5-hydroxymethylfurfural in sustainable betaine hydrochloride-based media

We show here that betaine hydrochloride (BHC), a co-product of the carbohydrate industry, can be used for the design of cheap and safe media capable of promoting the dehydration of fructose and inulin to HMF. In particular, in these BHC-based media, HMF was obtained with up to 84% yield, thus offering a competitive route to the traditional imidazolium-based ionic liquids.

Catalyst-free aqueous multicomponent domino reactions from formaldehyde and 1,3-dicarbonyl derivatives

Here we report a catalyst-free aqueous multicomponent domino reaction (MCR) capable of affording a wide range of valuable dihydropyran derivatives from simple, cheap and readily available reactants such as formaldehyde, 1,3-dicarbonyl derivatives, styrene, indole and aniline derivatives. Within the framework of green chemistry, these MCRs gather many advantages such as (i) utilization of water as a solvent, (ii) creation of up to six bonds in one sequence, (iii) 100% of carbon economy and (iv) water as a sole waste. These MCRs exhibit a broad substrate scope and open access to valuable chemicals traditionally produced through multistep processes involving catalysts or organic solvents. More generally, this work opens a new way for creating molecular complexity with maximum simplicity.

Acid-catalyzed dehydration of fructose and inulin with glycerol or glycerol carbonate as renewably sourced co-solvent.

Ionic liquids (ILs) can be partially substituted by glycerol or glycerol carbonate as cheap, safe, and renewably sourced co-solvents in the acid-catalyzed dehydration of fructose and inulin to 5-hydroxymethylfurfural (HMF). In the particular case of glycerol, we found that HMF can be conveniently extracted from the IL/glycerol (65:35) mixture with methylisobutylketone, limiting the reactivity of glycerol with HMF and allowing the recovery of HMF with a high purity (95 %). Influences of the fructose content, temperature, and the nature of the ionic liquid are also discussed. The possible use of industrial-grade glycerin is also investigated. We demonstrate that by using glycerol carbonate, up to 90 wt % of the IL can be successfully substituted, decreasing the environmental costs of traditional IL-based processes.

Dehydration of Highly Concentrated Solutions of Fructose to 5‐Hydroxymethylfurfural in a Cheap and Sustainable Choline Chloride/Carbon Dioxide System

Fête DES sciences: The dehydration of fructose and inulin to HMF is conveniently performed in a cheap and sustainable choline chloride/CO(2) deep eutectic solvent (DES) system. The medium is capable of converting high contents of fructose (>100 wt %) without affecting the yield of HMF (up to 72 %). The purity of the recovered HMF is >98%, and the reaction medium can be recycled.

Mechanocatalytic Deconstruction of Cellulose: An Emerging Entry into Biorefinery

Deconstructing cellulose: This highlight presents an emerging concept dealing with the mechanocatalytic deconstruction of biopolymers including cellulose, lignin, and lignocellulosic biomass. This dry treatment of biomass is expected to open new horizons in the field of biomass processing. In particular, mechanocatalysis is now considered as a promising entry into biorefinery.

Rational design of sugar-based-surfactant combined catalysts for promoting glycerol as a solvent.

Thumbnail image of graphical abstract A sugary treat: Here we report the great efficiency of sugar-based-surfactant combined catalysts for conducting selective base-catalyzed organic reactions in glycerol. Close control of the reaction selectivity was successfully obtained owing to the formation of catalytic hydrophobic pockets in glycerol (see figure). The advantages of our catalytic processes and its similarities with catalysis in water are also highlighted.