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The total amount of cellulose from paper, wood, food, and other human activity waste produced in the EU is in the order of 900 million tons per year. This resource represents a sizable opportunity to produce renewable chemicals and energy. This paper reports, unprecedently in the literature, the usage of four different urban wastes such as cigarette butts, sanitary pant diapers, newspapers, and soybean peels as cellulose fonts to produce valuable industrial intermediates such as levulinic acid (LA), 5-acetoxymethyl-2-furaldehyde (AMF), 5-(hydroxymethyl)furfural (HMF), and furfural. The process is accomplished by the hydrothermal treatment of cellulosic waste using both Brønsted and Lewis acid catalysts such as CH3COOH (2.5–5.7 M), H3PO4 (15%), and Sc(OTf)3 (20% w:w), thus obtaining HMF (22%), AMF (38%), LA (25–46%), and furfural (22%) with good selectivity and under relatively mild conditions (T = 200 °C, time = 2 h). These final products can be employed in several chemical sectors, for example, as solvents, fuels, and for new materials as a monomer precursor. The characterization of matrices was accomplished by FTIR and LCSM analyses, demonstrating the influence of morphology on reactivity. The low e-factor values and the easy scale up render this protocol suitable for industrial applications.

The reaction of trans-1,2-bis(4-methoxyphenyl)cyclohexane-1,2-diol with excess amounts (4 eq.) of tris(2,4-dibromophenyl)aminium hexachloro-antimonate affords only 1,6-bis(4-methoxyphenyl) hexane-1,6-dione through an oxidative cleavage. An analogous reaction of the corresponding cis-diol, gives mainly 2,2-bis(4-methoxyphenyl)cyclohexanone, whose formation might proceed through an oxidative rearrangement alternative, at least in part, to the classic acid catalysed pinacol rearrangement.

Unprecedented in the literature, levulinic acid (LA), one of the top value-added intermediates of chemical industry, is obtained from cigarette butts as cellulose feedstock by means of a one-pot hydrothermal process carried out at 200 °C for 2 h and catalysed by phosphoric acid. The protocol avoids the use of more aggressive and toxic H2SO4 and HCl, that are generally employed on several cellulose sources (e.g. sludge paper), thus minimizing corrosion phenomena of plants. Neither chemical pre-treatment of butts nor specific purification procedure of LA are required. Notably, by simply modifying acid catalyst (e.g. using CH3COOH), another top value-added fine chemical such as 5-hydroxymethylfuraldehyde (HMF) is obtained, thus widening the scope of the method. Being cigarette filters a waste available in quantities of megatonnes per year, they represent an unlimited at no cost source of cellulose, thus enabling the up-scale to an industrial level of LA production.

Photoreduction of CO2 with sunlight to produce solar fuels, also named artificial photosynthesis, is considered one of the most attractive strategies to face the challenge of reducing greenhouse gases and achieving climate neutrality. Following an approach in line with the principles of the circular economy, the low-cost catalytic system (1) based on an industrial by product such as steel slag was assessed, which was properly modified with nanostructured palladium on its surface in order to make it capable of promoting the conversion of CO2 into methanol and hydrogen through a two-stage process of photoreduction and thermal conversion having formic acid as the intermediate. Notably, for the first time in the literature steel slag is used as photoreduction catalyst.

The adhesive manufacturing industry needs more eco-sustainable processes. In this regard, the main road is to replace raw fossil materials with renewable resources or waste biomass, and simultaneously improve synthetic steps by using clean and greener reagents under mild conditions. In this paper, a synthetic pathway for producing biobased succinyl peroxide (SP) from waste biomass is reported, and then the application range of this polymerization agent to methacrylates and styrene-free resins is extended. At the same time, new formulations of pastes based on benzoyl or succinyl peroxide, displaying an almost complete biobased carbon content, are investigated and tested as cross-linking agents for mastic marble and unsaturated polyester resins. Physicochemical characterization of the final products and polymers is carried out with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR), Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance (NMR) and peak exothermic curve analyses.

Levulinic acid (LA), one of the top value-added intermediates of chemical industry, can be obtained by thermal hydrolysis (at 200 °C) from cigarette butts (as cellulose feedstock) catalysed by phosphoric acidic. The protocol avoids the use of more aggressive H2SO4 and HCl, that are generally employed on several cellulose sources (e.g. sludge paper), thus minimizing corrosion phenomena of plants. Neither chemical pre-treatment of butts nor specific purification procedure of LA are required. Notably, by simply modifying acid catalyst (e.g. using CH3COOH), another top value-added fine chemical such as 5-hydroxymethylfuraldehyde (HMF) is obtained, thus widening the scope of the method.Being cigarette filters a waste available in quantities of megatonnes per year, they represent an unlimited at no cost source of cellulose, thus enabling the up-scale to an industrial level of LA production.

For the first time, secondary steel slag, the material directly coming from ladle treatments, is used as a catalyst for the biodiesel production without undergoing any preliminary chemical or thermal modifications. Catalytic material 1, which has been pre-ground to sizes below 230 mesh, has been characterized for the surface textural properties and used as a catalyst in the transesterification of triglycerides of soybean oil to produce biodiesel. Reaction conditions were optimized by DOE method, revealing no interdependence between reaction parameters and results, and showed a catalytic activity comparable with that of an analogous slag-deriving catalyst reported in the literature.

Curcumin (CM) is a natural polyphenol well-known for its antioxidant and pharmaceutical properties, that can represent a renewable alternative to bisphenol A (BPA) for the synthesis of bio-based polycarbonates (PC). In the presented strategy, preparation of the CM-based PC was coupled with chemical recycling of the fossil-based BPA polycarbonate (BPA-PC) conducting a two-steps trans-polymerization that replaces BPA monomer with CM or its tetrahydrogenated colorless product (THCM). In the first step of synthetic strategy, depolymerization of commercial BPA-PC was carried out with phenol as nucleophile, according to our previous procedure based on zinc derivatives and ionic liquids as catalysts, thus producing quantitatively diphenyl carbonate (DPC) e BPA. In the second step, DPC underwent a melt transesterification with CM or THCM monomers affording the corresponding bio-based polycarbonates, CM-PC and THCM-PC, respectively. THCM was prepared by reducing natural bis-phenol with cyclohexene as a hydrogen donor and characterized by 1H-NMR and MS techniques. Polymerization reactions were monitored by infrared spectroscopy and average molecular weights and dispersity of the two biobased polymers THCM-PC and CM-PC were determined by means of gel permeation chromatography (GPC). Optical properties of the prepared polymers were also measured.

The valorization of glycerol (1), a waste of biodiesel production of Fatty Acid Methyl Esters (FAMEs), adopting a &ldquo, green&rdquo, approach, represents an important goal of sustainable chemistry. While the polymerization of 1 to hyperbranched oligomers is a well-established process, the linear analogues are difficult to obtain. In this context, we explore the reaction without the solvent of heterogeneous hybrid La(III)O-KIT-6 catalyst (2), which is based on lanthanum oxide on mesoporous silica gel, showing a superior linear selectivity compared to most of the analogous catalysts recently reported.

This study presents the synthesis of biowax esters (flow conditions) that can be used as a convenient procedure for future industrial applications. The biowax esters longer than C are prepared by the Fisher-type esterification of long-chain acids with fatty alcohols.

Unprecedented in literature, the conversion of aryl alkenes into ?-nitrostyrenes (2) or benzonitriles (3) with sodium nitrite can be governed by an appropriate choice of ionic liquid (IL) medium. A general trend was found for the selectivity of these processes, which depends on the nature of IL, with imidazolium-based ILs, such as [Bmim]Cl, that favor the C-H nitration leading to ?-nitrostyrenes, while tetraalkylammonium-based ILs, such as TBAA, privilege the C=C bond cleavage affording benzonitriles. Besides a substrate scope, mechanistic hypotheses were provided on the origin of the different selectivity in the two kinds of ILs, based on their own tunable properties such as polarity, viscosity, and solvent cage effects.

A new expeditious synthesis of tetramethyl salvianolic acid F is presented. Starting from the naturally occurring veratrole, the target molecule is easily obtained in a one-pot mode via a sequential double Heck coupling catalyzed by palladium nanoparticles dispersed in ionic liquids. The present method involves the chemoselective displacement of two different halogen atoms present on the veratrole ring and limits the need for tedious experimental procedures. A 66% of overall yield can be achieved, that represents, as far as we know, one of the best results present in the literature, until now. This protocol can also open the way for the synthesis of unnatural salvianolic-like compounds with potential bioactivity. (c) 2021 Elsevier B.V. All rights reserved.

A versatile catalyst based on halloysite and zinc oxide (HNT@ZnO) was prepared, for the first time, starting from ZnO commercial bulk form as Zn precursor source, in a one-pot procedure. This strategy gives the possibility to obtain small ZnO nanoparticles loaded on the HNT surface without the use of inorganic salts which envisage the removal of undesired anions and therefore a calcination process at high temperature. It was found that the presence of halloysite improved the UV–vis spectral absorption ability of ZnO. The hybrid was successful used as photocatalyst for the methylorange and rhodamine B degradation. In addition, after eight consecutive cycles for the methylorange photodegradation, the hybrid did not exhibit significant reduction in its photocatalytic performances confirming its stability. Based on trapping experiments and calculated energy bands we also proposed a photocatalytic mechanism. Furthermore, to evaluate the versatility of the synthetized HNT@ZnO hybrid, we used it as catalyst for biodiesel production from soybean oil, too. Also, in this case, the hybrid showed good catalytic performance and recyclability.

Biowaxes synthesized from vegetable fatty acids are an alternative to petrochemical paraffins. A simple way of access to these compounds involves Fisher-type esterification of long-chain acids and alcohols under acidic conditions, but long reaction times and harsh conditions are commonly required. In this study, for the first time in the literature, biowax esters are prepared under flow conditions cutting dramatically both reaction times (from 12 h to 30 min) and temperature conditions, with respect to batch procedures (from 90-120 °C to 55 °C). This approach brings substantial improvements to the biowax synthesis process from an economic and environmental point of view, thus making the method up-scalable to the industrial level.

A new protocol for biodiesel production is proposed, based on a binary ZnO/TBAI (TBAI = tetrabutylammonium iodide) catalytic system. Zinc oxide acts as a heterogeneous, bifunctional Lewis acid/base catalyst, while TBAI plays the role of phase transfer agent. Being composed by the bulk form powders, the whole catalyst system proved to be easy to use, without requiring nano-structuration or tedious and costly preparation or pre-activation procedures. In addition, due to the amphoteric properties of ZnO, the catalyst can simultaneously promote transesterification and esterification processes, thus becoming applicable to common vegetable oils (e.g., soybean, jatropha, linseed, etc.) and animal fats (lard and fish oil), but also to waste lipids such as cooking oils (WCOs), highly acidic lipids from oil industry processing, and lipid fractions of municipal sewage sludge. Reusability of the catalyst system together with kinetic (Ea) and thermodynamic parameters of activation (&Delta, G&Dagger, and &Delta, H&Dagger, ) are also studied for transesterification reaction.

Silicon nanowires (SiNWs) decorated by pulsed laser ablation with gold or copper nanoparticles (labeled as AuNPs@SiNWs and CuNPs@SiNWs) were investigated for their catalytic properties. Results demonstrated high catalytic performances in the Caryl–N couplings and subsequent carbonylations for gold and copper catalysts, respectively, that have no precedents in the literature. The excellent activity, attested by the very high turn over number (TON) values, was due both to the uniform coverage along the NW length and to the absence of the chemical shell surrounding the metal nanoparticles (MeNPs). A high recyclability was also observed and can be ascribed to the strong covalent interaction at the Me–Si interface by virtue of metal “silicides” formation.

Anatase (TiO2) and multiwalled carbon nanotubes bearing polyethylenimine (PEI) anchored on their surface were hybridized in different proportions according to a sol-gel method. The resulting nanocomposites (TiO2@PEI-MWCNTs), characterized by BET, XRD, XPS, SEM, and UV techniques, were found efficient catalysts for CO2 photoreduction into formic and acetic acids in water suspension and under visible light irradiation. PEI-grafted nanotubes co-catalysts are believed to act as CO2 activators by forming a carbamate intermediate allowing to accomplish the first example in the literature of polyamines/nanotubes/TiO2 mediated CO2 photoreduction to carboxylic acids.

An aromatic epoxy monomer, formed by glycidylation of gallic acid, was crosslinked by adopting different curing agents to obtain bio-based, crosslinked resins with suitable engineering properties. Specifically, tri- and tetra-glycidyl ether of gallic acid (GEGA) were obtained using a two-step synthesis. These bio-based monomers were cured in the following three epoxy formulations: a stiff cycloaliphatic primary amine, isophorone diamine, and a flexible polypropylene oxide amine (Jeffamine D-230). Next, the homopolymerization of GEGA was studied using an ionic initiator, N,N-dimethylbenzylamine, and a complex curing mechanism highlighted by calorimetric and mass spectra analysis. Calorimetric and rheological measurements were used to compare the curing behavior of the studied GEGA-based formulations. Mechanical properties of the gallic acid-based epoxy resins were comparable with those of standard epoxy resin formulations, based on di-glycidyl ether of bisphenol A. Thermogravimetric analysis of cured samples showed a relevant char content at high temperatures.

Copper(II) chloride catalyses the oxidative carbonylation of aminols, amine and alcohols to give 2-oxazolidinones, ureas and carbamates. Reaction proceeds smoothly in water under homogeneous conditions (P-tot=4 MPa; P-O2 = 0.6 MPat P-co), at 100 degrees C in relatively short reaction times (4 h) and without using bases or any other additives. This methodology represents an economic and environmentally benign non-phosgene alternative for the preparation of these three important N-containing carbonyl compounds. (C) 2015 Elsevier B.V. All rights reserved.

A useful protocol for waste bis-phenol A-polycarbonates (BPA-PC) chemical recycling is proposed based on a bifunctional acid/basic catalyst composed by nanostructured zinc oxide and tetrabutylammonium chloride (ZnO-NPs/NBu4Cl) in quality of Lewis acid and base, respectively. Retro-polymerization reaction proved to be of general application for several nucleophiles, including water, alcohols, amines, polyols, aminols and polyamines, leading to the complete recovery of BPA monomer and enabling the PC polymer to function as a green carbonylating agent (green phosgene alternative) for preparing carbonates, urethanes and ureas. A complete depolymerization can be obtained in seven hours at 100 °C and ZnO nanocatalyst can be recycled several times without sensible loss of activity. Remarkably, when polycarbonate is reacted with glycerol, it is possible to realize in a single process the conversion of two industrial wastes (BPA-PC and glycerol) into two valuable chemicals like BPA monomer and glycerol carbonate (the latter being a useful industrial solvent and fuel additive).

Palladium nanoparticles supported on chitosan (Pd-NPs@Chitosan) have been used for the first time in Suzuki cross coupling of bromo and iodoarenes carried out in ionic liquids. The reaction proceeded smoothly in molten tetrabutylammonium bromide (TBAB) affording unsymmetrical biaryls in good to excellent yields. A low catalyst loading (0.1%) is used and the catalyst can be recycled without deactivation. (C) 2013 Elsevier B. V. All rights reserved.

Palladium nanoparticles supported on chitosan are used in the Suzuki cross coupling of bromo and iodoarenes carried out in ionic liquids.

A systematic study on copper(II) as catalyst for the synthesis of glycerol carbonate via oxidative carbonylation is here reported for the first time. Copper(II) chloride has been found to efficiently promote the process under homogeneous conditions treating glycerol with CO:O 2 ( P tot = 4 MPa; P (O2) = 0.7 MPa), in DMA at 130 °C and in the presence of pyridine as co-catalyst. Excellent conversions (>92%) and selectivities (>93%) are obtained in relatively short reaction times (3–4 h) also with copper(II) complexes. The catalyst overall TON is evaluated and new experimental evidences are provided allowing significant advancements in the mechanism comprehension.

Copper halides, CuX2 (X =Cl, Br), promote the oxidative carbonylation of vicinal diols [1,2-ethandiol (1,2-ED), 1,2-propanediol (1,2-PD), 1,2-butanediol (1,2-BD)] into the corresponding 5-membered cyclic carbonates, under CO/O-2 (Ptot = 3 MPa; P-(02) = 0.5 MPa), at 373 K, in CH3CN and in the presence of a base as co-catalyst. Under these conditions, however, copper salts catalysts proved to be unstable (max turnover, 21.1 mol/mol), evolving into a pale green, insoluble and inactive material, by reaction with water, byproduct of the carbonylation process. Contrarily, by carrying out reactions directly in diol, and using DMF as the base, catalytic systems showed to be stable and efficient. Under these conditions, when approximately 40% of the diol has been converted into carbonate, CO2 begins to be formed, deriving from the CO oxidation promoted by H2O that accumulates in the system. The extent of this side reaction, which lowers the yield of CO into cyclic carbonate, increases with the progress of carbonylation. After a diol conversion of 70%, the oxidation of CO to CO2 becomes the main reaction and prevents the complete carbonylation of the diol. The most probable reaction mechanism is also reported and discussed. (C) 2012 Elsevier B.V. All rights reserved.