Cu-Catalyzed alkylation-cyanation type difunctionalization of styrenes with aliphatic aldehydes and TMSCN via decarbonylation.

A copper-catalyzed decarbonylative alkylation-cyanation of styrene derivatives with aliphatic aldehydes and trimethylsilyl cyanide to provide chain elongated nitriles is reported. Using TBHP as an oxidant and free radical initiator, the reaction can smoothly convert abundant α-di-substituted, α-mono-substituted and linear aliphatic aldehydes into the corresponding 3°, 2° and 1° alkyl radicals to initiate the subsequent radical-type difunctionalization of various styrenes.

Conjugated Microporous Polymer as Heterogeneous Ligand for Highly Selective Oxidative Heck Reaction.

A series of pyridine-type ligands containing C≡C bonds were designed and synthesized for selective oxidative Heck reaction. These ligands were utilized as functional units and integrated into the skeleton of conjugated microporous polymers. 6,6'-diiodo-2,2'-bipyridine and 1,3,5-triethynylbenzene were polycondensed via Sonogashira cross-coupling strategy to afford CMP-1 material. The resultant CMP-1 was used as a heterogeneous catalytic ligand for the PdII-catalyzed oxidative Heck reaction with high linear selectivity. The linear selectivity of CMP-1 is about 30 times higher than that of bipyridine-based monomer ligand. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts in controlling the regioselectivity in organic reactions.

Anti-hyperglycaemic effect of labdane diterpenes isolated from the rhizome of Amomum maximum Roxb., an edible plant in Southwest China.

Amomum maximum Roxb. rhizome is a fork medicine mainly used in South and Southeast Asia. In present study, the hypoglycaemic effects of the ethanolic extract of A. maximum rhizome were demonstrated both on α-glucosidase assay in vitro and streptozotocin (STZ)-induced postprandial hyperglycaemia in mice. Furthermore, six labdane diterpenes, amoxanthin A (1), ottensinin (2), coronarin D (3), coronarin D methyl ether (4), isocoronarin D (5), and zerumin (6), were isolated from its ethyl acetate sub-fraction with the guidance of α-glucosidase inhibitory activity. Among these compounds, 2 and 6 exhibited significant inhibitory effect on α-glucosidase, as well as on STZ-induced high postprandial blood glucose levels in mice. Additionally, molecular docking analysis revealed that 2 and 6 could firmly bind to the active sites of α-glucosidase. These results suggest that compounds 2 and 6 are the main anti-hyperglycaemic agents present in A. maximum, which may demonstrate potential beneficial effects in diabetes management.

A review for natural polysaccharides with anti-pulmonary fibrosis properties, which may benefit to patients infected by 2019-nCoV.

Pulmonary fibrosis (PF) is a lung disease with highly heterogeneous and mortality rate, but its therapeutic options are now still limited. Corona virus disease 2019 (COVID-19) has been characterized by WHO as a pandemic, and the global number of confirmed COVID-19 cases has been more than 8.0 million. It is strongly supported for that PF should be one of the major complications in COVID-19 patients by the evidences of epidemiology, viral immunology and current clinical researches. The anti-PF properties of naturally occurring polysaccharides have attracted increasing attention in last two decades, but is still lack of a comprehensively understanding. In present review, the resources, structural features, anti-PF activities, and underlying mechanisms of these polysaccharides are summarized and analyzed, which was expected to provide a scientific evidence supporting the application of polysaccharides for preventing or treating PF in COVID-19 patients.

Engineering cobalt oxide by interfaces and pore architectures for enhanced electrocatalytic performance for overall water splitting.

The development of efficient electrocatalysts for overall water splitting is important for future renewable energy systems. Herein, macroporous CoO covered by Co/N-doped graphitic carbon nanosheet arrays (mac-CoO@Co/NGC NSAs) were constructed by engineering a mesoporous CoO nanowire (mes-CoO NWAs) core with highly conductive Co nanoparticles coated by a N-doped graphitic carbon (Co/NGC) shell. The in situ derived Co/NGC shell not only introduces electrocatalytic active sites for the hydrogen evolution reaction (HER) but also promotes the oxygen evolution reaction (OER) through the strong interaction between the CoO core and the Co/NGC shell. Moreover, the highly conductive Co/NGC shell crosslinks the isolated mesoporous CoO nanowires into a nanosheet rich in macropores, ensuring effective electron and mass transfer. Furthermore, the chemically stable N-doped graphitic carbon layer and physically stable hierarchical nanosheet arrays ensure the stability of the catalyst. Owing to the desirable interfaces and pore architecture, the as-prepared mac-CoO@Co/NGC NSAs can serve as highly effective, binder-free electrocatalysts for overall water splitting with a stable cell voltage of 1.62 V at 10 mA cm-2 for 35 h.

A conjugated microporous polymer as a recyclable heterogeneous ligand for highly efficient regioselective hydrosilylation of allenes.

Pyridines containing adjacent C[triple bond, length as m-dash]C bonds were utilized as ligand units and integrated into the skeleton of conjugated microporous polymers. The resultant Pd-CMP-1 was first applied as a highly efficient heterogeneous catalytic system for Pd-catalyzed allene hydrosilylation towards a wide range of allenes to produce branched allylsilanes with high regioselectivity. The ligand units of the polymer, along with the confinement effect of the porous structure, jointly regulated the regioselectivity. The parts-per-million (ppm) levels of Pd, coordinated with the recyclable heterogeneous ligand, show promise for industrial applications. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts to control the regioselectivities in allene hydrosilylation.

Hierarchical Porous Prism Arrays Composed of Hybrid Ni-NiO-Carbon as Highly Efficient Electrocatalysts for Overall Water Splitting.

Searching for an economical and efficient water splitting electrocatalyst is still a huge challenge for hydrogen production. This work reports one-step synthesis of hierarchical porous prism arrays (HPPAs) composed of Ni-NiO nanoparticles embedding uniformly in graphite carbon (Ni-NiO/C HPPAs), which is derived from metal-organic framework (CPO-27-Ni) prism arrays grown on nickel foam (NF). Remarkable features of the prism arrays, synergistic effect of Ni-NiO/C, porous graphite carbon, high conductive NF, and good contact between catalyst and current collector result in excellent electrocatalytic performance of Ni-NiO/C HPPAs@NF. Ni-NiO/C HPPAs@NF shows a small overpotential of ∼49.48 mV at the current density of 10 mA cm-2, low Tafel slope of 74 mV dec-1 and robust stability for hydrogen evolution reaction (HER) in alkaline media. Especially, the overpotential for HER of Ni-NiO/C HPPAs@NF is only ∼132 mV at the current density of 185 mA cm-2, almost the same as the value from the Pt/C. Furthermore, for oxygen evolution reaction in basic media, Ni-NiO/C HPPAs@NF shows better catalytic activity, lower Tafel slope and higher durability than precious IrO2. The above finding offers an effective strategy to design the bifunctional electrocatalysts for overall water splitting.

Thiophene-Alkyne-Based CMPs as Highly Selective Regulators for Oxidative Heck Reaction.

Thiophenes containing an adjacent C≡C group as ligands for PdII-promoted organic reactions are reported for the first time. These ligands were utilized as catalytic sites and integrated into the skeleton of conjugated microporous polymers. By employing these CMP materials as selective regulators, oxidative Heck reactions between arylboronic esters and electronically unbiased alkenes provide highly selective linear products.