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This Personal Account reviews the sequence of scientific discoveries that led to a catalytic plastic conversion technology that resulted in the creation of a spin‐off company called Plastogaz from the Ecole Polytechnique Fédérale de Lausanne (Switzerland). The story begins with research on the catalytic valorization of CO2, carried out by two PhD students and a master student, and the connections and steps subsequently made, ultimately leading to a plastic transformation technology. The Personal Account highlights the value of diverse research topics within a research group, the benefits of connections between chemistry and chemical engineering, that can lead to interesting synergies and atypical breakthroughs. [ABSTRACT FROM AUTHOR]

The direct carboxylation of aromatic alkynes with CO2, a cheap and widely available C1 source, is the most attractive method for the synthesis of carboxylic acids. Here we show that direct carboxylation of terminal alkynes can be simply performed in near‐quantitative yield in four hours with anhydrous Cs2CO3 under mild conditions without need of a metal catalyst. [ABSTRACT FROM AUTHOR]

Combining CO2-chemistry with biomass conversion allows renewable polymeric materials including polycarbonates and polyhydroxyurethanes (PHUs) to be generated. The demand for robust materials with modular properties that can be prepared on an industrial scale is important and, to date, the most important polymeric materials are derived from petrochemicals. These materials inevitably result in CO2 emissions, and therefore making robust materials from renewable sources will contribute to a more sustainable society. An attractive way to address this challenge is to combine biomass transformations with CO2-fixation and material science. An identified target that combines all three aspects involves the preparation of PHUs (or non-isocyanate polyurethanes, NIPUs) via the polymerization of fully renewable cyclic carbonates derived from biomass and CO2 with a diamine compound that can also been derived from biomass sources. In this review, we critically analyze the progress in catalyst development for the efficient transformation of epoxides and CO2 to cyclic carbonates and polycarbonates. We also discuss the synthesis of PHUs from cyclic carbonates and diamines (not restricted to fully renewable compounds), including challenges in regiocontrol and biodegradability, as well as the role catalysts play in the synthesis of these polymers. [ABSTRACT FROM AUTHOR]

We report a ruthenium‐modified zeolite which efficiently transforms propylene carbonate to propylene glycol and methane, under solvent‐free conditions. The catalyst achieved high product selectivity and no significant ageing effect was observed after multiple cycles. The resulting liquid product (water‐containing glycol) can be directly used as anti‐freeze solution and the gas phase can directly be used as an energy carrier in the form of H2‐enriched methane. This process efficiently bridges energy storage and an important chemical synthesis under sustainable (CO2 consuming) conditions. OMEGA is not the end: A nanocrystalline ruthenium catalyst, embedded into a zeolite, catalyses the hydrogenolysis of cyclic carbonates into glycols and methane. The catalyst displays unprecedented selectivity towards methane, and the reaction may be considered as an extension of the OMEGA process, in which both a valuable liquid and gaseous product are formed. [ABSTRACT FROM AUTHOR]

We show that ionic liquids (ILs) interact with electron-rich, porous polyphosphazene (PPZ), to form hybrid PPZ-IL nanoreactors able to simultaneously capture and transform CO2 into carbonates. The PPZ nanospheres swell in organic solvents and effectively absorb IL cations by virtue of the electron-rich sites, while leaving the anions exposed and increasing their nucleophilicity. This leads to considerably higher catalytic activity compared to the IL alone in the cycloaddition reaction of CO2 to epoxides. The cation shielding effect is dependent on the structure of the IL cation and, hence, the catalytic activity can be tuned by varying the structure of the cation in the IL and DFT calculations were used to rationalize the experimentally observed differences in catalytic activity. These studies indicate that PPZ nanospheres could find widespread uses in catalysis, acting as active nanosupports for homogeneous catalysts, not only for the transformations of CO2, but also for other substrates. [ABSTRACT FROM AUTHOR]

Membrane technologies enable the facile separation of complex mixtures of gases, vapours, liquids and/or solids under mild conditions. Simultaneous chemical transformations can also be achieved in membranes by using catalytically active membrane materials or embedded catalysts, in so-called membrane reactors. A particular class of membranes containing or composed of ionic liquids (ILs) or polymeric ionic liquids (pILs) have recently emerged. These membranes often exhibit superior transport and separation properties to those of classical polymeric membranes. ILs and pILs have also been extensively studied as separation solvents, catalysts and co-catalysts in similar applications for which membranes are employed. In this review, after introducing ILs and their applications in catalysis, catalytic membranes and recent advances in membrane separation processes based on ILs are described. Finally, the nascent concept of catalytic IL membranes is highlighted, in which catalytically active ILs/pILs are incorporated into membrane technologies to act as a catalytic separation layer. [ABSTRACT FROM AUTHOR]

A series of dicationic styrene-functionalized imidazolium-based salts, in which the two imidazolium rings are bridged by a functionalized spacer, are prepared. The salts are polymerized to afford cross-linked imidazolium-based ionic polystyrene materials, which, owing to the presence of the functionalized spaces, should be highly active organocatalysts for the cycloaddition of CO2 to epoxides to afford cyclic carbonates (CCE reaction). The catalytic activities of the polymers are evaluated in the CCE reaction. The most active catalyst incorporates a diol functionality and is active at 80 °C and a pressure of 4 bar at a loading of 5 mol %, which is comparable to the most active organocatalysts. Moreover, high yields can be obtained under atmospheric pressure upon increasing the temperature to 120 °C. Under harsher conditions, the catalyst is highly active at a loading one order of magnitude lower, highlighting the importance of benchmark conditions for the CCE reaction. Moreover, the polymer catalysts are advantageous because they can be used at low catalyst loadings, the carbonate product is easily isolated in pure form, and loss of activity of the recovered polymer catalyst is not observed during reuse. [ABSTRACT FROM AUTHOR]

Valorization of CO2, an abundant C(1) synthon, into platform chemicals is of growing interest. In this context, a key reaction is the cycloaddition of CO2 to epoxides to form carbonates (CCE). A series of organocatalysts for this reaction, based on imidazolium salts modified with a styrene functional group and a second variable functional group, were prepared and characterized. Both the ionic salts and ionic polymers derived from the salts were evaluated in this reaction. In general, the monomers perform slightly better than the polymers; however, the latter are considerably more convenient to use. Of the catalysts studied, the ionic polystyrene imidazolium salt with an ammonium functionality shows highest activity, tolerates a range of epoxides, and can be recycled multiple times without loss of activity. [ABSTRACT FROM AUTHOR]

The synthesis of cyclic carbonates from epoxides and CO2 is a well-established reaction, whereas the synthesis of cyclic carbonates from diols and CO2 is considerably more challenging, and few efficient catalysts are available. Here, we describe heterocyclic carbene catalysts, including one derived from a cheap and efficient thiazolium salt, for this latter reaction. The reaction proceeds at atmospheric pressure in the presence of an alkyl halide and Cs2CO3. Reaction mechanisms for the transformations involved are also proposed. [ABSTRACT FROM AUTHOR]

The catalytic N-formylation and N-methylation of amines using CO2 as the carbon source represents a facile and sustainable approach for the synthesis of pharmaceuticals and natural products. Herein, we describe highly effective and inexpensive thiazolium carbene-based catalysts derived from vitamin B1 for the N-formylation and N-methylation of amines, using polymethylhydrosiloxane (PMHS) as a reducing agent, which operate under ambient conditions. [ABSTRACT FROM AUTHOR]

N-Acetyl-d-glucosamine (NAG), the monomer of the world's second most abundant biopolymer chitin, has been for the first time converted to its corresponding amide/amino substituted sugar alcohols, smaller C2–4 polyols and N-acetylmonoethanolamine (NMEA), over noble metal catalysts in the presence of hydrogen in water. Four commercialized catalysts were investigated, and Ru/C exhibited the best performance―achieving 8.7% NMEA, 6.1% C4 polyols, and 71.9% C6 polyols (N-containing) under 180 °C, 40 bar H2, 1 h with 1 mol% loading. Kinetic studies were conducted, which revealed four major reaction pathways that lead to various products. In particular, retro-aldol reaction-hydrogenation was confirmed to be the pathway forming NMEA. The effects of additives (NaOH and WO3) on the reaction were also tested. [ABSTRACT FROM AUTHOR]