ceverelst

The Cover Feature shows that two types of zeolites (BEA* and MFI) were used as catalysts (saws) to respectively break the C−O and C−C bonds of lignin-first monomers obtained from soft wood. The developed catalytic strategy provides a new approach to produce catechol from renewable feedstocks. More information can be found in the Research Article by X. Wu et al.

AA, my my: The production of adipic acid (AA) by a two-step pathway is studied. Ru/Al₂O₃ catalyst is used to obtain THFDCA and HAA (see graphic) by hydrogenation of furandicarboxylic acid. The ionic liquid [MIM(CH₂)₄SO₃H]I serves as both a reaction medium for conveying hydrogen and a highly catalytic system for furan ring-opening toward AA with 99 % yield.

Abstract

Efficient catalytic ring-opening coupled with hydrogenation is a promising but challenging reaction for producing adipic acid (AA) from 2,5-furan dicarboxylic acid (FDCA). In this study, AA synthesis is carried out in two steps from FDCA via tetrahydrofuran-2,5-dicarboxylic acid (THFDCA) over a recyclable Ru/Al₂O₃ and an ionic liquid, [MIM(CH₂)₄SO₃H]I (MIM=methylimidazolium) to deliver 99 % overall yield of AA. Ru/Al₂O₃ is found to be an efficient catalyst for hydrogenation and hydrogenolysis of FDCA to deliver THFDCA and 2-hydroxyadipic acid (HAA), respectively, where ruthenium is more economically viable than well-known palladium or rhodium hydrogenation catalysts. H₂ chemisorption shows that the alumina phase strongly affects the interaction between Ru nanoparticles (NPs) and supports, resulting in materials with high dispersion and small size of Ru NPs, which in turn are responsible for the high conversion of FDCA. An ionic liquid system, [MIM(CH₂)₄SO₃H]I is applied to the hydrogenolysis of THFDCA for AA production. The [MIM(CH₂)₄SO₃H]I exhibits superior activity, enables simple product isolation with high purity, and reduces the severe corrosion problems caused by the conventional hydroiodic acid catalytic system.

Color is central to scientific communication, but its use comes with the responsibility to ensure universally accessible and accurate data presentation. This short Viewpoint Article aims to sensitize the chemical community to the importance of mindful color choices in scientific illustrations.

Abstract

Color is a central element to scientific communication, but its use comes with the responsibility to ensure universally accessible and accurate data presentation. This short Viewpoint Article aims to sensitize the chemical community to the importance of mindful color choices in scientific illustrations.

Publication date: 13 April 2022

Source: Tetrahedron Letters, Volume 95

Author(s): Tingting Li, Bo Xu

Nature, Published online: 28 February 2022; doi:10.1038/d41586-022-00507-7

The Front Cover shows two people hitting substances (C−H/C−X) in a wooden barrel with wooden hammers which metaphors the mechanical grinding of the reactants for C−H/C−X functionalization. Five representative active pharmaceutical ingredients (APIs) together with grinding agents are splattering out, with “medicinal mechanochemistry” highlighted in golden font. The design of the Front Cover is inspired by the process of making Chinese New Year Cake at the Spring Festival, a traditional food made from glutinous rice flour by beating with wooden hammers. More information can be found in the Review by J. Yu et al.

Synthesis
DOI: 10.1055/a-1736-6703

Design of Experiments (DoE) is extensively and routinely used in industry; however, in recent decades, it has gained increasing interest from academia in organic synthesis. The use of chemometrics is an attractive strategy to find the real optimum in chemical reactions, especially when affected by several variables. DoE has been applied in a growing number of synthetic transformations over the years, where it undoubtedly helps in the process of optimisation, saving costs and time. This review concisely discusses the chemometric basis of Design of Experiments and highlights several examples in which DoE is applied in organic synthesis.1 Introduction2 Chemometric Basis of DoE3 DoE Applied in Catalysis: Selected Examples3.1 DoE in Metal Catalysis3.2 DoE in Biocatalysis3.3 DoE in Organocatalysis4 Conclusions
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Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Article in Thieme eJournals:
Table of contents  |  Abstract  |  Full text

Metal-promoted carbonylation of alkenes is established for d-block metals, whilst prior work with aluminium has been limited by reversible C=C coordination and decomposition of CO insertion products. This work shows how the aluminyl anion allows the non-reversible carbonylation of ethene using carbon monoxide under mild conditions. A bimetallic pathway involving an intramolecular 1,2-hydrogen shift was identified and supported by DFT calculations.

Abstract

The potassium aluminyl [K{Al(NON^Dipp)}]₂ ([NON^Dipp]²⁻=[O{SiMe₂NDipp}₂]²⁻, Dipp=2,6-iPr₂C₆H₃) activates ethene towards carbonylation with CO under mild conditions. An isolated bis-aluminacyclopropane compound reacted with CO via carbonylation of an Al−C bond, followed by an intramolecular hydrogen shift to form K₂[Al(NON^Dipp)(μ-CH₂CH=CO-1κ² C ^1,3-2κO)Al(NON^Dipp)Et]. Restricting the chemistry to a mono-aluminium system allowed isolation of [Al(NON^Dipp)(CH₂CH₂CO-κ² C ^1,3)]⁻, which undergoes thermal isomerisation to form the [Al(NON^Dipp)(CH₂CH=CHO-κ² C,O)]⁻ anion. DFT calculations highlight the stabilising influence of incorporated benzene at multiple steps in the reaction pathways.