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International audience; Levoglucosan (LGA) is an anhydrous pyrolytic sugar that has gained increasing attention in recent years. The highest focus on the conversion of LGA and other anhydro carbohydrates obtained from cellulose aims at the valorization of these molecules and their application in multiple fields such as chemical and pharmaceutical industries. LGA presents a rigid structure with three hydroxyl groups on a pyranose ring, making it a promising building block for the synthesis of bio-based thermoplastic polymers with pending OH groups as soon as a regioselective polymerization is reached. In this work, a lipase-catalyzed series of LGA-containing terpolymers were synthesized for the first time via regioselective transesterification in two-stage polymerization. LGA was reacted with diethyl adipate/sebacate and α,ω-diols to give terpolymers with up to 35% of LGA content (related to the α,ω-diol content), number-average molecular weights (Mn) of up to 7900 g·mol–1, and up to 94% yield. It was observed that the amount of LGA in the polymer structure affects the crystallinity, hydrophilicity, and melting point of the polymers. We also evaluated the effect of LGA loading and the comonomer’s size on yields, molecular weight, and the incorporation of LGA in the polymer structure. High loads of LGA lead to a decrease in the yield, but a higher molecular weight and higher extent of LGA incorporation in the polymer can be obtained.

International audience; Oxidative deamination is part of the metabolic pathways of amino acid oxidase and glutamate dehydrogenase enzymes, and enables obtaining α-keto acid from amino compound with ammonia as a by-product. This work presents the utilization of Pt-based catalyst composed of small platinum nanoparticles supported on industrial silica support (Pt/SiO2). This nanozyme was tested in the oxidative deamination reaction of two amino compounds: 5-hydroxymethylfurfurylamine (HMFA) to 5-hydroxymethylfurfural (HMF) and glutamic acid (GA) to α-ketoglutaric acid (KGA). This paper outlines the use of Pt nanozymes with deaminase-like activity. We showed the ability of this nanozymes to be selective and active in liquid phase oxidative deamination of HMFA and glutamic acid in a 6 to 9 pH range at 60°C under atmospheric pressure. Pt/SiO2 nanozyme actually plays as a deaminase mimic with high HMFA conversion (60%) and cumulative yield to the corresponding desaminated keto compounds (67%).

International audience; This work investigates batch and continuous-flow heterogeneous catalytic hydrogenation of a mixture of cafestol and kahweol (C&K) to obtain pure cafestol. These diterpenes were extracted from green coffee beans, and hydrogenation was performed using well-established palladium catalysts (Pd/C, Pd/CaCO3, Pd/BaSO4, and Pd/Al2O3) and a carbon black-supported Pd catalyst coated by a covalently tethered SiO2 shell with mesoporous texture (Pd/CB@SiO2), all partially deactivated with quinoline. Pd/C 10% poisoned with 1 wt % quinoline gave the best result for batch reaction, producing cafestol from kahweol with high selectivity (>99%) after 10 min. Excellent selectivity was also obtained with the catalyst Pd/CB@SiO2 with only 1% Pd. In addition, Pd/C-quinoline adapted for continuous-flow experiments exhibited the best catalytic activity, also providing cafestol with excellent selectivity (>99%) after 9.8 s.

International audience; Studies involving the transformation of lignocellulosic biomass into high value-added chemical products have been intensively conducted in recent years. Its matrix is mainly composed of cellulose, hemicellulose and lignin, being, therefore, an abundant and renewable source for obtaining several platform molecules, with levoglucosan (LG) standing out. This anhydrous carbohydrate can be acylated to obtain carbohydrate fatty acid esters (CFAEs). Here, these compounds were obtained via enzymatic acylation of LG, commercially obtained (Start BioScience®), with different acyl donors in continuous flow. Through the experimental design using a model reaction, it was possible to optimize the reaction conditions, temperature and residence time, obtaining a maximum conversion at 61 C and 77 min. In addition, there was a productivity gain of up to 100 times in all comparisons made with the batch system. Finally, CFAEs were applied in tests of interfacial tension and biological activity. For a mixture of 4-and 2-O-lauryl-1,6-anhydroglucopyranose (MONLAU), the minimum interfacial tension (IFT min) obtained was 96 mN m À1 and the critical micelle concentration (CMC) was 50 mM. Similar values were obtained for a mixture of 4-and 2-O-palmitoyl-1,6-anhydroglucopyranose (MONPAL), not yet reported in the literature, of 88 mN m À1 in 50 mM. For a mixture of 4-and 2-O-estearyl-1,6anhydroglucopyranose (MONEST) and 4-and 2-O-oleoyl-1,6-anhydroglucopyranose (MONOLE), CMC was higher than 60 mM and IFT min of 141 mN m À1 and 102 mN m À1 , respectively. Promising data were obtained for minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of MONLAU against Staphylococcus aureus strains at 0.25 mM.

International audience; Biocatalytic transesterification is commonly carried out employing lipases in anhydrous organic solvents since hydrolases usually prefer hydrolysis over acyl transfer in bulk water. However, some promiscuous acyltransferases can catalyze acylation in an aqueous solution. In this study, a rational design was performed to enhance the acyltransferase selectivity and substrate scope of the Pyrobaculum calidifontis VA1 esterase (PestE). PestE wild type and variants were applied for the acylation of monoterpene alcohols. The mutant PestE_I208A is selective for (–)-menthyl acetate (E-Value = 55). Highly active acyltransferases were designed, allowing for complete conversion of (–)-citronellol to citronellyl acetate. Additionally, carvacrol was acetylated but with lower conversions. To the best of our knowledge, this is the first example of the biocatalytic acylation of a phenolic alcohol in bulk water. In addition, a high citronellol conversion of 92% was achieved with the more environmentally friendly and inexpensive acyl donor ethyl acetate using PestE_N288F as a catalyst. PestE_N288F exhibits good acyl transfer activity in an aqueous medium and low hydrolysis activity at the same time. Thus, our study demonstrates an alternative synthetic strategy for acylation of compounds without organic solvents.

International audience; The search for the optimal coupling of several types of catalysts has inspired the development of multicatalytic hybrid materials (MCHMs) featuring chemical and biological catalysts co-immobilised on the same support. This complex interdisciplinary strategy, located at the crossroads of chemistry, biology, and materials science, calls for a wide range of skills and offers access to MCHMs with diverse catalytic properties and applications. In particular, numerous organic and inorganic supports, both rigid or flexible, have been used to develop remarkable hybrid catalysts that exhibit synergetic effects and achieve yields and enantiomeric excesses unattainable through the separate use of catalyst constituents even in onepot/one step processes. As the spearhead of hybrid catalysis, MCHMs concentrate the very essence of this field, requiring seamless communication and collaboration between chemists, biologists, materials scientists, and modelling specialists. Future developments in this area are expected to revolutionise catalysis and make it an inter-or even transdisciplinary research area. † This article is dedicated to P. H. Dixneuf for his outstanding contribution to organometallic chemistry and catalysis.

On estime aujourd’hui que 90 % des procédés chimiques font appel à au moins un catalyseur, et que 30 à 40 % de l’économie mondiale dépendent directement ou indirectement de l’utilisation de catalyseurs. Ces espèces chimiques ou biologiques sont extrêmement répandues au niveau industriel ; elles permettent de mieux maitriser la sélectivité et la spécificité d’une grande diversité de réactions chimiques pour la formation à façon de composés cibles très variés, en jouant sur les chemins réactionnels et donc les énergies d’activations, tout en favorisant le plus souvent la cinétique. De manière générale, les catalyseurs sont le lieu d’environnements physicochimiques aux propriétés différentes de celles des milieux réactionnels conventionnels. Ils favorisent ou permettent des évènements réactionnels spécifiques (acte catalytique) mettant en œuvre leurs propriétés, et permettent même la création de nouveaux intermédiaires réactionnels facilitant et/ou orientant les réactions. La diversité des catalyseurs permet d’accéder à un panel extrêmement large de mécanismes moléculaires plus ou moins complexes dont la compréhension permet en retour un meilleur contrôle des réactions et l’optimisation de procédés catalytiques, ainsi que leur couplage raisonné selon des réactions dites « multi-catalytiques » qui tirent bénéfice des propriétés supplémentaires inédites de ces systèmes catalytiques ainsi assemblés. It is estimated today that 90% of chemical processes use less than one catalyst, and that 30-40% of the world economy depends directly or indirectly on the use of catalysts. These chemical or biological species are extremely widespread at the industrial level; they make it possible to better control the selectivity and specificity of a wide variety of chemical reactions for the customised formation of very varied target compounds, by playing on the reaction pathways and thus the activation energies, while most often favouring kinetics. In general, catalysts are the site of physicochemical environments with properties different from those of conventional reaction media. They promote or allow specific reaction events (catalytic act) implementing their properties, and even allow the creation of new reaction intermediates facilitating and/or directing reactions. The diversity of catalysts provides access to an extremely wide range of more or less complex molecular mechanisms, the understanding of which allowing for a better control of reactions and optimisation of catalytic processes, as well as their reasoned coupling according to so-called "multi-catalytic" reactions that benefit from the additional novel properties of these catalytic systems assembled in this way. 454

International audience; In this work we present a perspective study on the synthesis of 2,5-furandicarboxylic acid (FDCA), a highly promising building block for resins and polymers. FDCA is presumed as a green replacement for (fossil-based) terephthalate – a predominant compound in polymer and resin manufacture nowadays, with a potential market size of several 100 M€. However, the use of FDCA is still limited because due to its high price and the several issues linked to its industrial scale production. Herein we discuss the synthesis of FDCA from glucose using heterogeneous catalysts and base-free conditions emphasizing also the possibilities and the perspectives in an efficient FDCA production process directly from glucaric acid (glucose derivative) applying new-engineered nanocatalysts (hybrid catalysts). These processes are able to avoid the non-selective and highly expensive step of glucose isomerization to fructose.

International audience; 2,5‐furandicarboxylic acid (FDCA) is one of the most important bio‐sourced building blocks and several routes have been reported for its synthesis. FDCA is presumed to be an ideal green alternative to terephthalate, which is one of the predominant monomers in polymer industry. This Minireview concerns the synthesis of FDCA by using various carboxylation reactions and discusses the synthesis of FDCA starting from furoic acid and CO2 and using different catalytic and stoichiometric processes. This process is of high interest, as it avoids the glucose isomerization step and selectivity issues observed during the 5‐hydroxymethylfurfural oxidation step of the current alternative route to FDCA. Discussion focuses on the main parameters that govern selectivity and activity in the carboxylation processes. Moreover, various previously described processes, such as the Henkel reaction and enzymatic, homogeneous catalytic, and photoelectrocatalytic processes, are also discussed.

Furfural (FF) is a strategic product for the development of highly valued chemicals from biomass. The oxidation product of FF, furoic acid (FA), is an important precursor for the synthesis of green esters, such as methyl furoate. Taking into account issues with the direct furfural oxidation, furfural derivatives, such as alkyl furoates, can be easily prepared via oxidative esterification. Here, Au nanoparticles that were immobilized on alkaline-earth metal oxide supports were studied for the oxidative esterification of furfural while using alcohol as both reactant and solvent. The formation of esters is favored by the presence of basic sites on catalyst surface, resulting in high selectivity, preventing the formation of the acetal as a by-product. The Au/MgO sample provided up to 95% methyl furoate (MF) yield, a fast reaction rate, and high performance for furfural:Au molar ratios between 50 and 300. Furthermore, this catalyst was stable during reuse, since both the selectivity and the activity were maintained after four cycles. Oxidative esterification products were achieved in the presence of other alcohols, leading to the formation of esters of up to C5 (isopentyl furoate) with high selectivity (&gt, 99%). Linear and branched esters were formed, but the long-chain linear alcohols resulted in higher yields, such as n-butyl furoate in 94% yield.

The high life expectancy of the world population provokes increase in demand for food and energy. As a result, the intense industrialization and the application of fossil sources is responsible for high levels of CO2 emission and waste generation. To mitigate the CO2 emission a practical solution at the very short term is urgently needed. The capture of CO2 and its application in chemical processes for the valorization of residual biomass are of great importance nowadays. The application of CO2 in the selective carboxylation of furoic acid for the production of 2,5-furandicarboxylic acid (FDCA), a bio-based monomer, has been an important step towards obtaining biopolymers to replace petroleum-based plastics such as polyethylene terephthalate (PET). In this project report, we discuss on the current challenges for obtaining the 2,5-FDCA precursor from the furfural in two main routes involving oxidation and carboxylation via heterogeneous catalysis. We present the main objectives and discuss the importance of this research for the development of more sustainable processes.

Dans la recherche de couplages optimaux de catalyseurs, les chercheurs pionniers en catalyse hybride se sont tout naturellement tournés vers l’élaboration de matériaux multi-catalytiques hybrides (MMCH) constitués à partir de co-immobilisation sur un même support de catalyseurs chimiques et biologiques. Cette exécution disciplinaire innovante, située au carrefour de la chimie, la biologie et la science des matériaux, fait appel à de très nombreuses compétences, et sa complexité n’a d’égale que la diversité des propriétés catalytiques que peuvent offrir ces MMCH. En particulier, l’utilisation d’une large variété de supports organiques et inorganiques, rigides et flexibles, a d’ores et déjà permis l’élaboration de quelques déclinaisons remarquables de catalyseurs hybrides démontrant de véritables effets de synergie, avec des rendements et des excès énantiomériques finaux inatteignables en utilisant des catalyseurs de manière isolée, et ce même dans des procédés en 1P1S. Véritable fer de lance de la catalyse hybride, les MMCH concentrent l’essence même de ce domaine, nécessitant communication et collaboration extrêmement étroites entre chimistes, biologistes, chercheurs en science des matériaux, ou encore en modélisation. Son développement sera sans aucun doute dans un futur proche le témoin d’une véritable (r)évolution de la recherche en catalyse vers des thématiques inter-, voire transdisciplinaires. In the search for optimal coupling of catalysts, it is quite naturally that pioneering researchers in hybrid catalysis have turned toward the development of hybrid multi-catalytic materials (HMCMs) constituted from the co-immobilization on the same carrier of chemical and biological catalysts. Such an innovative disciplinary variant, located at the crossroads of chemistry, biology and materials sciences, calls for a wide range of skills ; its complexity is only equaled by the diversity of catalytic properties that HMCMs can offer. In particular, the use of a wide variety of organic and inorganic supports, either rigid or flexible, has already led to the development of some remarkable examples of hybrid catalysts exhibiting real synergy effects, with yields and final enantiomeric excesses that are unreachable when using each catalyst separately, even in 1P1S processes. As the spearhead of hybrid catalysis, HMCMs concentrate the very essence of this field, requiring seamless communication and collaboration between chemists, biologists, materials science researchers and modeling specialists. Its development will in the near future undoubtedly witness a real (r)evolution of research in catalysis towards inter-, or even trans-disciplinary themes. 454

Hybrid catalysis emerged about twenty years ago. This discipline aims at combining a chemical catalyst with a biological catalyst to produce a multi-catalytic system, with additional properties compared to those of single catalysts, has long remained little studied because it calls on a wide range of skills that are rarely brought together in joint work.In recent years, however, the growing interest in inter- or even transdisciplinary research has greatly benefited its development, and the number of examples of hybrid catalysis applications is now growing exponentially. Historically developed for kinetic resolution and deracemisation processes, hybrid catalysis is now illustrated in many fields, with very different purposes, from the regeneration of costly enzyme co-substrates to the implementation of integrated catalytic tandems allowing the synthesis of previously inaccessible compounds.In this respect, it benefits from numerous advances in chemistry and biology/molecular biology, whether in terms of new modelling or analytical techniques, the possibility of designing new, more efficient and tolerant catalysts, or the development of more efficient reaction devices thanks to reactor and process engineering. This important diversity of catalysts and techniques now represents a promising hope for the renewal of catalysis that is often struggling to meet tomorrow’s environmental challenges.; La catalyse hybride a émergé il y a une vingtaine d’années. Cette discipline, qui vise à combiner un catalyseur chimique avec un catalyseur biologique afin de produire un système multi-catalytique possédant des propriétés supplémentaires par rapport à celles des catalyseurs unitaires, est longtemps restée peu étudiée car faisant appel à des compétences très diversifiées rarement rassemblées au sein de travaux communs.Ces dernières années, l’accroissement de l’intérêt pour les recherches inter- voire transdisciplinaires a largement bénéficié à son développement et le nombre d’exemples d’applications de la catalyse hybride croît aujourd’hui de manière exponentielle. Historiquement mise au point pour les procédés de résolution cinétique et de déracémisation, elle s’illustre désormais dans de très nombreux domaines, avec des finalités très différentes, depuis la régénération de cosubstrats enzymatiques coûteux, jusqu’à la mise en place de tandems catalytiques intégrés permettant la synthèse de composés jusque-là inaccessibles.Elle bénéficie à ce titre de nombreuses avancées en chimie et biologie/biologie moléculaire, qu’il s’agisse des nouvelles techniques de modélisation ou analytiques, de la possibilité de concevoir de nouveaux catalyseurs plus efficaces et tolérants, ou encore de l’élaboration de dispositifs réactionnels plus performants grâce aux génies des réacteurs et des procédés. Cette importante diversité de catalyseurs et de techniques représente un espoir prometteur pour le renouveau d’une catalyse qui peine souvent à répondre aux défis environnementaux de demain.

The effectiveness of chemical as well as biological catalysts for carrying out chemical reactions on an industrial level is no longer to be demonstrated. Their specificity and selectivity make them essential tools for many processes, and as such, they represent a major key in the establishment of tomorrow's industry. Historically, catalysts have mostly been used in a unitary manner, with processes involving several catalysts most often forming part of multi-stage strategies. However, the last two decades have seen a significant increase in research into multi-catalytic reactions that combine two or more catalysts in order to benefit from collaborative effects. While catalysts of different natures are very rarely used together, the combination of a chemical catalyst and a biocatalyst, known as "hybrid catalysis", is most likely the most promising type of multi-catalytic reaction because of the unprecedented diversity and efficiency allowed. Nevertheless, it remains the most complex to implement, calling on skills from different fields (chemistry, biology, materials, etc.). The prospects it offers are giving riseto pioneering work that is pushing researchers to develop new strategies for overcoming the limitations and inhibitions that inevitably arise when these two types of catalyst are forced to work together.; L’efficacité des catalyseurs chimiques et biologiques pour la réalisation de réactions chimiques au niveau industriel n’est plus à démontrer. Leur spécificité et sélectivité en font des outils essentiels à de nombreux procédés, et ils représentent à ce titre un outil majeur dans l’établissement de l’industrie de demain.Historiquement, les catalyseurs ont été très majoritairement utilisés de manière unitaire, les procédés en faisant intervenir plusieurs s’inscrivant le plus souvent dans des stratégies multi-étapes. Cependant, les deux dernières décennies ont vu un essor de la recherche autour des réactions multi-catalytiques qui combinent deux catalyseurs ou plus afin de bénéficier d’effets collaSi des catalyseurs de natures différentes ne sont que très rarement mis en jeu ensemble, la combinaison d’un catalyseur chimique et d’un biocatalyseur, appelée « catalyse hybride », représente très probablement le type de réaction multi-catalytique le plus prometteur de par la diversité et l’efficacité inédites permises. Elle n’en demeure pas moins la plus complexe à mettre en œuvre, faisant appel à des compétences de domaines différents (chimie, biologie, matériaux, etc.). Les perspectives offertes donnent lieu à des travaux pionniers qui poussent les chercheurs à mettre au point de nouvelles stratégies permettant de contourner les limitations et inhibitions qui ne manquent pas d’apparaitre lorsque l’on force ces deux types de catalyseurs à travailler de concert.

Every year, a large amount of residual agroindustrial waste has been generated and only around 10% is in fact reused. The development of new strategies for biomass valorization is important to add value to these commodities, since biomass is an excellent alternative feedstock to obtain chemicals of interest from renewable resources. The major compound of pyrolytic treatment of lignocellulosic biomass is levoglucosan (1,6-anhydroglucopyranose), an anhydro-sugar that can be transformed into glucose and is greatly valued in the most diverse industrial sectors as a surfactant, emulsifier, or even a lubricant. In this work, levoglucosan was acylated by lipase-catalyzed transesterification in acetonitrile with great conversions and selectivities with different acyl donors such as ethyl esters of lauric, palmitic, stearic, and oleic acids prepared in situ in an integrated strategy mediated by commercial lipases Novozym435 (N435), PSIM, and the home-made biocatalyst CaLB_epoxy. As a result, all biocatalyst generated mostly monoesters, with N435 being more selective to produce lauric esters (99% at 50&deg, C) and PSIM to produce oleic esters (97% at 55 &deg, C) while CaLB_epoxy was more selective to produce oleic esters of levoglucosan (83% at 55&deg, C). This is the first report in the literature on the production of high selectivity levoglucosan esters.

Recent papers estimates that about 40 % of drugs present chiral amines in their structure and their synthesis in a sustainable and cost-competitive way is still a challenge for the industry. Kinetic resolution is one of the most applied method to produce these desired compounds where the association with lipase as a catalyst is a good alternative. However, the use of separate racemization catalyst and enzymes in the reaction medium still limits recovery, recycling and can occasionally be responsible for decreasing in selectivity for the desired product. In this work we proposed the synthesis and characterization of a hybrid magnetic catalyst composed containing lipase CaL B and Pd immobilized on the same recovered nanometric magnetic support for the application on Dynamic Kinetic Resolution of (rac)-1-phenylethylamine both in batch and continuous flow conditions. As results it was possible to achieve 99 % of conversion, with 95 % of selectivity and 93 % of enantiomeric excess after 12 h in batch. For a continuous flow system, it was possible to achieve 95 % of conversion with 71 % of selectivity and ee > 99 % after 60 min of reaction. The hybrid catalyst had around 50−100 nm with nanoparticulated Pd (5−10 nm) on its surface, presented a superparamagnetic behavior without remaining magnetization and 22 emu/g of saturation magnetization.