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Over the last several years many publications have focused on sustainable monomers to synthesize polymeric materials such as bio-based polyurethane foams (PUs). PUs is a class of materials with a lot of industrial applications (from insulation panels, structural reinforcement, sandwich construction to medical application)1 and are generally composed by polyol, isocyanate and several additives. PUs mechanical and functional properties are determined by the typology of polyols and isocyanate precursors, the distribution of the soft and hard segments from which PUs are composed and by the morphological structure in terms of open or closed cells. To avoid the problem of the big amount of chemicals produced from petroleum source, such as polyols and isocyanate utilized in the PUs formulation (the goal to produce sustainable PUs where both precursors are obtained from renewable resources is still a challenge), nanoparticles made from green and renewable materials are added replacing partially the polyol. Furthermore by modifying the surface of nanoparticle with isocyanate functional group also the amount of isocyanate can be reduced. An example of suitable nanoparticles that could be used is nanocrystalline cellulose (CNC). The combination of cellulose properties, such as low cost, chemical modification capacity, high Young's modulus, biodegradability, and abundance in nature, with features of the nanosized materials such as very large specific surface area, high aspect ratio, light weight, and outstanding reinforcing potential justifies the big interest of scientists towards this issue. On the other hand the cellulose hydrophilicity leads a bad dispersion in non polar matrices, the consequential nanocrystal aggregation decreases thermo-physical and mechanical properties of the nanocomposite. Herein, we propose the use of modified CNC (m-CNC) as reactive filler in polyurethane foams (PUs, fig. 1). To overcome the cellulose hydrophilicity, the CNC has been modified by linking covalently the bio-polyols on the m-CNC surface. In our strategy the silylation reaction in water to modify the surface of CNC followed by bio-polyol grafting was used. The CNC-grafted-polyols has been tested in the preparation of different composite PUs.

Over the last several years many publications have focused on sustainable monomers to synthesize polymeric materials such as bio-based polyurethane foams (PUs). PUs is a class of materials with a lot of industrial applications (from insulation panels, structural reinforcement, sandwich construction to medical application)1 and are generally composed by polyol, isocyanate and several additives. PUs mechanical and functional properties are determined by the typology of polyols and isocyanate precursors, the distribution of the soft and hard segments from which PUs are composed and by the morphological structure in terms of open or closed cells. To avoid the problem of the big amount of chemicals produced from petroleum source, such as polyols and isocyanate utilized in the PUs formulation (the goal to produce sustainable PUs where both precursors are obtained from renewable resources is still a challenge), nanoparticles made from green and renewable materials are added replacing partially the polyol. Furthermore, by modifying the surface of nanoparticle with isocyanate functional group also the amount of isocyanate can be reduced. An example of suitable nanoparticles that could be used is nanocrystalline cellulose (CNC). The combination of cellulose properties, such as low cost, chemical modification capacity, high Young's modulus, biodegradability, and abundance in nature, with features of the nanosized materials such as very large specific surface area, high aspect ratio, light weight, and outstanding reinforcing potential2 justifies the big interest of scientists towards this issue. On the other hand, the cellulose hydrophilicity leads a bad dispersion in non polar matrices, the consequential nanocrystal aggregation decreases thermo-physical and mechanical properties of the nanocomposite3. Herein, we propose the use of modified CNC (m-CNC) as reactive filler in polyurethane foams (PUs, fig. 1). To overcome the cellulose hydrophilicity, the CNC has been modified by linking covalently the bio-polyols on the m-CNC surface. In our strategy the silylation reaction in water to modify the surface of CNC followed by bio-polyol grafting was used. The CNC-grafted-polyols has been tested in the preparation of different composite PUs.

The combination of metal nanoparticles (Pd or Pt NPs) with NAD-dependent thermostable alcohol dehydrogenase (TADH) resulted in the one-flask catalytic double reduction of 3-methyl-2-cyclohexenone to 3-(1S,3S)-methylcyclohexanol. In this article, some assumptions about the interactions between a chemocatalyst and a biocatalyst have been proposed. It was demonstrated that the size of the NPs was the critical parameter for the mutual inhibition: the bigger the NPs, the more harmful for the enzyme they were, even if the NPs themselves were only moderately inactivated. Conversely, the smaller the NPs, the more minimal the TADH denaturation, although they were dramatically inhibited. Resuming, the chemocatalysts were very sensitive to deactivation, which was not related to the amount of enzyme used, while the inhibition of the biocatalyst can be strongly reduced by minimizing the NPs/TADH ratio used to catalyze the reaction. Among some methods to avoid direct binding of NPs with TADH, we found that using large Pd NPs and protecting their surfaces with a silica shell, the overall yield of 3-(1S,3S)-methylcyclohexanol was maximized (36%).

Continuous flow processes have recently emerged as a powerful technology for performing chemical transformations since they ensure some advantages over traditional batch procedures. In this work, the use of commercially available and affordable PEEK (Polyetheretherketone) and PTFE (Polytetrafluoroethylene) HPLC (High Performance Liquid Chromatography) tubing as microreactors was exploited to perform organic reactions under continuous flow conditions, as an alternative to the commercial traditional glass microreactors. The wide availability of tubing with different sizes allowed quickly running small-scale preliminary screenings, in order to optimize the reaction parameters, and then to realize under the best experimental conditions a reaction scale up for preparative purposes. The gram production of some Active Pharmaceutical Ingredients (APIs) such as (S)-Pregabalin and (S)-Warfarin was accomplished in short reaction time with high enantioselectivity, in an experimentally very simple procedure.

One-pot combinations of sequential catalytic reactions can offer practical and ecological advantages over classical multi-step synthesis schemes. In this context, the integration of enzymatic and chemo-catalytic transformations holds particular potential for efficient and selective reaction sequences that would not be 10 possible using either method alone. Here we report the one-pot combination of alcohol dehydrogenasecatalysed asymmetric reduction of 2-azido ketones and Pd nanoparticle-catalysed hydrogenation of the resulting azido alcohols, which gives access to both enantiomers of aromatic 1,2-amino alcohols in high yields and excellent optical purity (ee >99%). Furthermore, we demonstrate the incorporation of an upstream azidolysis and a downstream acylation step into the one-pot system, thus establishing a highly 15 integrated synthesis of the antiviral natural product (S)-tembamide in 73% yield (ee >99%) over 4 steps. Avoiding the purification and isolation of intermediates in this synthetic sequence leads to an unprecedentedly low ecological footprint, as quantified by E-factor and solvent demand.