Developing cleaner chemical processes often involves sophisticated flow-chemistry equipment that is not available in many economically developing countries. For reactions where it is the data that are important rather than the physical product, the networking of chemists across the internet to allow remote experimentation offers a viable solution to this problem.

A self‐optimizing approach is used as a tool for targeting known and unknown materials in the continuous reaction of aniline, dimethyl carbonate (DMC) and tetrahydrofuran (THF) in supercritical CO2 on γ‐Al2O3. The study led to the formation of methylated anilines or carbamate derivatives and unusual addition products with THF including pyrrolidines and N‐alkylated anilines. The identification of these products leads to the development of a plausible mechanism for the reactions. The system not only demonstrates a high flexibility that the self‐optimization approach provides, including the ability to optimize for a variety of products by using a single catalyst, but also the ability to discover unexpected and original synthetic reactions.

This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector.

The synthesis of trimethylamine (TMA) through am ulticomponent combination of ammonia with carbon dioxide and molecular hydrogenb yu sing ah omogeneous ruthenium catalyst was explored. The use of [Ru(triphos)(tmm)] [triphos: 1,1,1-tris-(diphenylphosphinomethyl)ethane, tmm:t rimethylenem ethane] together with aluminumt rifluoromethanesulfonatea s ac o-catalyst resulted in high ammonia conversion and excellent selectivity for TMA in organic solvents. Aqueous solutions of ammonium chloride were methylated almost quantitatively to the corresponding hydrochloride salt (i.e.,T MA·HCl) in ab iphasic solvent system by using the same Ru complex without the need for any co-catalyst.Methylamines, the simplest members of the aliphatic amine family,r epresent highly importanta nd versatile intermediates within the chemical supply chain. The industrial significance of methylamines is reflected by aw orldwide annual production larger than 1.3 10 6 tw ith ag rowing rate of 3.5% per annum. [1] These basic chemicals are generally used as valuable buildingb locks for the synthesis of solvents, surfactants, ionexchange resins, and synthetic fibers, as well as agrochemical and pharmaceutical products. [2] Methylamines are prepared on industrials cale by the exothermicr eactiono fa mmonia (NH 3 )a nd methanol( CH 3 OH) with an amorphous silica-alumina catalyst in fixed-bed reactors at 390-430 8C( Scheme 1A). The composite equilibria within the reaction network result in complex product mixtures, and the three possible methylamines (mono-, di-, and trimethylamine:M MA, DMA andT MA) are generally produced with moderate selectivity for the individual product, largely controlled by the NH 3 /CH 3 OH feed ratio. [2, 3] Moreover,M MA, DMA, TMA, and NH 3 form an azeotropic mixture, and the use of zeolite-based catalysts in combinationw ith methanol results in dimethyl ether (DME) as an additional byproduct. [4] Consequently,t he downstream purificationp rocess is laboriousa nd requiresatrain of four to five distillationcolumns, which finally results in integrated production plants at economy of scale. [2a, 5] The synthesis of the ammonium chlorides is typically achieved in as ubsequents tep (Scheme 1B).Herein, we report anovel catalytic approach for the selective synthesis of trimethylaminea nd its hydrochloride by using carbon dioxide (CO 2 )a sarenewable C 1 building block fort he formation of the three methyl groups on ammonia in the presence of molecular hydrogen. [6] In previousw ork from our group, aw ell-defined and highly versatile [Ru(triphos)(tmm)] [triphos:1 ,1,1-tris(diphenylphosphinomethyl)ethane,t mm:t rimethylene methane] catalystw as developed for the hydrogenation of CO 2 to methanola nd the utilizationo fC O 2 and H 2 for the N-methylation of primary ands econdary amines. [7] On the basis of these investigations, the directt riple N-methylation of NH 3 (Scheme 1C)orNH 4 Cl (Scheme 1D)byusing acombination of CO 2 and H 2 was targeted.In the mid-1990s, the group of Baiker worked on this challenging transformation and d...

The use of γ-Al2O3 as a heterogeneous catalyst in scCO2 has been successfully applied to the amination of alcohols for the synthesis of N-alkylated heterocycles. The optimal reaction conditions (temperature and substrate flow rate) were determined using an automated self-optimising reactor, resulting in moderate to high yields of the target products. Carrying out the reaction in scCO2 was shown to be beneficial, as higher yields were obtained in the presence of CO2 than in its absence. A surprising discovery is that, in addition to cyclic amines, cyclic ureas and urethanes could be synthesised by incorporation of CO2 from the supercritical solvent into the product.

Titanium alkoxides can catalyze efficient and selective synthesis of cyclic carbonates through CO2 insertion into epoxides when tetrabutylammonium bromide or iodide is used as a cocatalyst. Of the series of synthesized titanium alkoxides, the most active catalyst was one bearing an aliphatic bidentate alkoxide ligand, and it produced propylene carbonate under benign conditions (100 °C, 15 bar CO2, 3 h) with turnover frequencies of up to 116 h–1. The effect of reaction parameters such as pressure, temperature, and catalyst/cocatalyst molar ratio were also studied in order to optimize the catalytic system.

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