Ruthenium‐Catalyzed Synthesis of Dialkoxymethane Ethers Utilizing Carbon Dioxide and Molecular Hydrogen

Abstract

The synthesis of dimethoxymethane (DMM) by a multistep reaction of methanol with carbon dioxide and molecular hydrogen is reported. Using the molecular catalyst [Ru(triphos)(tmm)] in combination with the Lewis acid Al(OTf)3 resulted in a versatile catalytic system for the synthesis of various dialkoxymethane ethers. This new catalytic reaction provides the first synthetic example for the selective conversion of carbon dioxide and hydrogen into a formaldehyde oxidation level, thus opening access to new molecular structures using this important C1 source.

Future perspectives for formaldehyde: pathways for reductive synthesis and energy storage

“…8 The reaction has been validated for a wide range of linear and branched aliphatic alcohols (C1-C10) and benzyl alcohol. The achieved turnovers reached about 200 TONs for methanol and varied for the higher aliphatic alcohols between 50 and 120, showing a dependency of the chain-length, with an activity increase for long-chain alcohols.…”

“…For example, oxymethylene ethers (OME), synthesised from formaldehyde and alcohols, are investigated as potential candidates for combustion fuels and fuel additives. [8][9][10] It could be envisioned to extend this approach using long-chain bioderived alcohols, thus resulting in long-chain OMEs suitable to complement biofuels such as biodiesel (Scheme 1). 8 Worth mentioning is also the long established use of solid formaldehyde derivatives as solid fuel tablets for direct combustion commonly used for small camping stoves especially in military equipment since the 1930s.…”

“…[8][9][10] It could be envisioned to extend this approach using long-chain bioderived alcohols, thus resulting in long-chain OMEs suitable to complement biofuels such as biodiesel (Scheme 1). 8 Worth mentioning is also the long established use of solid formaldehyde derivatives as solid fuel tablets for direct combustion commonly used for small camping stoves especially in military equipment since the 1930s. These ashless burning fuel tablets consist of 1,3,5,-trioxane, or more commonly of hexamethylenetetramine (also known as urotropin), and the latter ones are commonly sold and known under the commercial name Esbit®.…”

“…Scheme 1. C1-interconversion network of aqueous formaldehyde in relation to: (I) a reductive low-temperature formaldehyde synthesis, 2,5,7 (II) the decomposition of formaldehyde to syngas, 4 (III) OME as potential combustion fuel (additives) 8,10 and (IV) the application as LOHC for hydrogen fuel cells.…”

Tailor‐made Molecular Cobalt Catalyst System for the Selective Transformation of Carbon Dioxide to Dialkoxymethane Ethers

“…[3] and methanol. [5] These compounds are becoming increasingly important as fuel or fuel additives, owing to their ability to lower soot and NO x formation in existing combustion engines. [5] These compounds are becoming increasingly important as fuel or fuel additives, owing to their ability to lower soot and NO x formation in existing combustion engines.…”