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The Inside Cover picture shows that a renewable p-xylene (PX) can be directly synthesized from biomass-derived 2,5-dimethylfuran and acrylic acid over scandium(III) triflate (Sc(OTf)₃) and H₃PO₄ under mild conditions. A subsequent one-pot decarboxylation step results in an overall 63 % selectivity towards PC at 90 % conversion of 2,5-dimethylfuran. The production of PX is of great importance in the synthesis of bulk chemicals like terephthalic acid, which is widely used in several industrial applications. More details can be found in the Full Paper by Ni et al. on page 2394 in Issue 11, 2017 (DOI: 10.1002/cssc.201700020).

The Back Cover picture shows the selective oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid as a bioplastics precursor. The reaction is performed using a simple non-precious metal catalyst system based on cost-effective and ubiquitously available manganese oxide, sodium bicarbonate, and molecular oxygen. More details can be found in the Communication by Hayashi et al. on page 654 in Issue 4, 2017 (DOI: 10.1002/cssc.201601443).

The production of aromatic platform chemicals from biomass-derived feedstocks is of considerable importance in biomass conversion. However, the development of effective routes with simple steps and under mild conditions is still challenging. In this work, we report an original route for the direct synthesis of p-xylene from 2,5-dimethylfuran and acrylic acid catalyzed by scandium(III) triflate (Sc(OTf)₃) in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim]NTf₂) under mild conditions. An overall 63 % selectivity towards p-xylene and 78 % selectivity towards aromatics were obtained at 90 % conversion of 2,5-dimethylfuran by enhancing the dehydration and introducing an extra one-pot decarboxylation step. Furthermore, various dienes and dienophiles were employed as reactants to extend the substrate scope. The aromatic compounds were obtained in moderate yields, which proved the potential of the method to be a generic approach for the conversion of bio-based furanics into renewable aromatics.

A triflate synthesis of xylene: Renewable p-xylene is directly synthesized from biomass-derived 2,5-dimethylfuran and acrylic acid over scandium(III) triflate (Sc(OTf)₃) and H₃PO₄ in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim]NTf₂) under mild conditions. A subsequent one-pot decarboxylation step results in an overall 63 % selectivity towards p-xylene at 90 % conversion of 2,5-dimethylfuran.

Clusters with diverse structures and functions have been used to create novel cluster-assembled materials (CAMs). Understanding their self-assembly process is a prerequisite to optimize their structure and function. Herein, two kinds of unlike organo-functionalized inorganic clusters are covalently linked by a short organic tether to form a dumbbell-shaped Janus co-cluster. In a mixed solvent of acetonitrile and water, it self-assembles into a crystal with a honeycomb superstructure constructed by hexagonal close-packed cylinders of the smaller cluster and an orderly arranged framework of the larger cluster. Reconstruction of these structural features via coarse-grained molecular simulations demonstrates that the cluster crystallization and the nanoscale phase separation between the two incompatible clusters synergistically result in the unique nano-architecture. Overall, this work opens up new opportunities for generating novel CAMs for advanced future applications.

How to pack dumbbells: The size asymmetry and Janus characteristics of a dumbbell-shaped co-cluster synergistically define its self-assembly in solution into crystals with a filled-honeycomb superstructure. The Janus co-cluster consists of a POM (purple sphere) and a POSS (green sphere) linked by an organic tether.

The solvent-free selective oxidation of alcohols by O₂ without any additives has been studied using palladium nanoparticles supported on a titanate nanobelt. The catalysts were prepared by polyol reduction and impregnation with different kinds of supports. They were evaluated in oxidation reactions of benzyl alcohol. The calcined titanate nanobelt was found to be the best support for the solvent-free Pd-catalyzed oxidation of alcohols and excellent catalytic activity as well as high selectivity to the corresponding benzaldehyde could be obtained. Moreover, palladium nanoparticles immobilized on the calcined titanate nanobelt could completely suppress the formation of toluene and benzoic acid, an effect that might be caused by the enhanced basic nature and morphology of the support. The catalyst was not only active and selective towards carbonyl compounds, but also recyclable under the oxidation conditions. This catalyst was also applicable for the oxidation of other alcohols.

Nanobelt-supported nanocatalyst: A titanate nanobelt has been found to be an excellent support for solvent-free Pd-catalyzed alcohol oxidation, which could completely suppress the formation of toluene and benzoic acid. The basic nature and morphology of the support played a crucial role for the reaction performance.

The Back Cover picture shows the crystal structure of a sulfonic acid-functionalized 2D covalent organic framework (COF) and its application as a highly effective solid acid catalyst with excellent catalytic activity and chemoselectivity for the conversion of fructose into 5-hydroxymethylfurfural (HMF) and 2,5-diformylfuran (DFF). A sulfonated 2D crystalline COF, termed TFP–DABA, is synthesized directly using 1,3,5-triformylphloroglucinol (TFP) and 2,5-diaminobenzenesulfonic acid (DABA) via a Schiff base condensation reaction followed by irreversible enol-to-keto tautomerization. This COF is highly efficient for fructose conversion with remarkable yields (97% for HMF and 65% for DFF). This study provides encouragement for further exploration of COFs as heterogeneous catalysts for bio-based chemical conversion and related applications. More details can be found in the Communication by D. Zhao et al. on page 3208 in Issue 19, 2015 (DOI: 10.1002/cssc.201500755).

A new low-energy pathway is reported for the electrochemical reduction of CO₂ to formate and syngas at low overpotentials, utilizing a reactive ionic liquid as the solvent. The superbasic tetraalkyl phosphonium ionic liquid [P₆₆₆₁₄][124Triz] is able to chemisorb CO₂ through equimolar binding of CO₂ with the 1,2,4-triazole anion. This chemisorbed CO₂ can be reduced at silver electrodes at overpotentials as low as 0.17 V, forming formate. In contrast, physically absorbed CO₂ within the same ionic liquid or in ionic liquids where chemisorption is impossible (such as [P₆₆₆₁₄][NTf₂]) undergoes reduction at significantly increased overpotentials, producing only CO as the product.

The superbasic RTIL (room-temperature ionic liquid) [P₆₆₆₁₄][124Triz] provides an alternative low-energy pathway for conversion of CO₂ into formate. This is the first time chemical binding of the CO₂ molecule to the anion of a RTIL has been shown to decrease the activation energy for electrochemical reduction, by distortion of the CO₂ geometry from linear to bent.

The Cover shows the promising utilization of functionalized carbon nanotubes (CNTs) for the transformation of biomass into building-block chemicals. In their Full Paper, W. Deng, Y. Yang, Y. Wang, and co-workers demonstrate that a functionalized CNT-supported Pt catalyst is highly efficient and stable for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA), in water without any base additives. It has been clarified that the oxygen-containing functional groups, in particular carbonyl/quinone and/or phenol groups, on CNT surfaces play crucial roles in FDCA formation. More details can be found in the Full Paper by Zhou et al. on page 2853 in Issue 18, 2015 (DOI: 10.1002/cctc.201500352).

We report the preparation and hydrogenation performance of a single-site palladium catalyst that was obtained by the anchoring of Pd atoms into the cavities of mesoporous polymeric graphitic carbon nitride. The characterization of the material confirmed the atomic dispersion of the palladium phase throughout the sample. The catalyst was applied for three-phase hydrogenations of alkynes and nitroarenes in a continuous-flow reactor, showing its high activity and product selectivity in comparison with benchmark catalysts based on nanoparticles. Density functional theory calculations provided fundamental insights into the material structure and attributed the high catalyst activity and selectivity to the facile hydrogen activation and hydrocarbon adsorption on atomically dispersed Pd sites.

One (sheltered) atom is enough: The unique porous structure of carbon nitride enables the incorporation of isolated palladium atoms in a stable manner. This heterogeneous single-site catalyst outperforms state-of-the-art catalysts that are based on modified palladium nanoparticles in selective hydrogenation reactions.