Hydrothermal Growth of Centimeter-Scale CuO Plates: Planar Chromium(III) Oligomer as a Facet-Directing Agent

In this work, a simple hydrothermal method was developed to synthesize CuO plates in centimeter scale for the first time. Plates of up to 20 μm thickness and several square millimeters in area have been prepared. The unusual size was obtained under ultrahigh-concentration NaOH and a planar chromium­(III) oligomer, which served as a new kind of inorganic facet-directing agent. The obtained CuO plates were glossy black, free-standing, and crack-free. The chromium­(III) oligomer offered ideal chemically active sites for adsorbing and confining Cu²⁺ ions. They could be adsorbed on the surface of Cu­(OH)₄^2– clusters via hydrogen-bonding interaction, which thus modified the growth orientation. The as-synthesized centimeter-scale CuO plates could possibly serve as substrates and electronic materials with potential applications

Iron-Catalyzed Asymmetric Haloazidation of α,β-Unsaturated Ketones: Construction of Organic Azides with Two Vicinal Stereocenters

Organic azides play important roles in synthetic chemistry, chemical biology, drug discovery, and material science. Azido-functionalization of alkenes is one of the most efficient procedures for rapid introduction of azide group into organic compounds. But only a few examples have been documented in the catalytic asymmetric version of the azidation of alkenes. Herein, we report an unprecedented highly diastereo- and enantioselective bromoazidation of α,β-unsaturated ketones catalyzed by chiral <i>N,N</i>′-dioxide/Fe­(OTf)₂ complexes. An array of aryl, heteroaryl, and alkyl substituted α,β-unsaturated ketones were transformed to the corresponding α-bromo-β-azido ketones in high yields with excellent diastereo- and enantioselectivities. The catalytic system was also applicable for chloroazidation and iodoazidation of chalcone. Kinetic studies and some control experiments suggested that the reaction might proceed via a 1,4-addition/halogenation pathway

Catalytic Asymmetric Intra- and Intermolecular Haloetherification of Enones: An Efficient Approach to (−)-Centrolobine

A catalytic asymmetric intra- and intermolecular haloetherification of electron-deficient alkenes (halogen = Cl, Br, I) has been realized by the use of chiral metal complexes of <i>N,N</i>′-dioxides. In the presence of a chiral Fe­(III) complex, a series of tetrahydropyran derivatives were obtained in good yields (up to 99% yield) with a high level of enantioselectivities (up to 97% ee). Promoted by a chiral Ce­(III) complex, chiral oxepane derivatives could be given in good results. Moreover, the intermolecular haloetherification of chalcones catalyzed by Sc­(III) complex using MeOH as nucleophile is demonstrated. This methodology also can be successfully applied to the synthesis of (−)-Centrolobine. Meanwhile, a reasonable reaction mechanism was proposed

Additional file 1: Figure S1. of Tuning the Synthesis of Manganese Oxides Nanoparticles for Efficient Oxidation of Benzyl Alcohol

XRD pattern of manganese precursor S1 before and after calcination. (TIF 3067 kb

Additional file 4: Figure S4. of Tuning the Synthesis of Manganese Oxides Nanoparticles for Efficient Oxidation of Benzyl Alcohol

SEM images of manganese precursor S2 before calcination and calcined at 400, 600, and 800 °C. (TIF 452 kb

Additional file 5: Figure S5. of Tuning the Synthesis of Manganese Oxides Nanoparticles for Efficient Oxidation of Benzyl Alcohol

HR-TEM images of manganese precursor S1 calcined at 600 °C. (TIF 1762 kb

Additional file 3: Figure S3. of Tuning the Synthesis of Manganese Oxides Nanoparticles for Efficient Oxidation of Benzyl Alcohol

SEM images of manganese precursor S1 before calcination and calcined at 400, 600, and 800 °C. (TIF 397 kb

Additional file 2: Figure S2. of Tuning the Synthesis of Manganese Oxides Nanoparticles for Efficient Oxidation of Benzyl Alcohol

XRD pattern of manganese precursor S2 before and after calcination. (TIF 3066 kb

A new diarylheptanoid from <i>Alpinia officinarum</i> promotes the differentiation of 3T3-L1 preadipocytes

<p>A new diarylheptanoid, namely <i>trans</i>-(4<i>R</i>,5<i>S</i>)-epoxy-1,7-diphenyl-3-heptanone (<b>1</b>), and a new natural product, 7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl-hepta-4<i>E</i>,6<i>E</i>-dien-3-one (<b>2</b>), were obtained from the aqueous extract of <i>Alpinia officinarum</i> Hance, together with three other diarylheptanoids, 5-hydroxy-1,7-diphenyl-3-heptanone (3), 1,7-diphenyl-4E-en-3-heptanone (4) and 5-methoxy-1,7-diphenyl-3-heptanone (5). The structures were characterised mainly by analysing their physical data including IR, NMR and HRMS. This study highlights that the 4,5-epoxy moiety in <b>1</b> is rarely seen in diarylheptanoids. In addition, the five isolates were tested for their differentiation activity of 3T3-L1 preadipocytes. The results showed that these compounds could dose-dependently promote adipocyte differentiation without cytotoxicity (IC₅₀ > 100 μM).</p

Synthesis and Characterization of Poly(vinylphosphonic acid-<i>co</i>-acrylic acid) Copolymers for Application in Bone Tissue Scaffolds

Poly­(vinylphosphonic acid-<i>co</i>-acrylic acid) (PVPA-<i>co</i>-AA) has recently been identified as a possible candidate for use in bone tissue engineering. It is hypothesized that the strong binding of PVPA-<i>co</i>-AA to calcium in natural bone inhibits osteoclast activity. The free radical polymerization of acrylic acid (AA) with vinylphosphonic acid (VPA) has been investigated with varying experimental conditions. A range of copolymers were successfully produced and their compositions were determined quantitatively using ³¹P NMR spectroscopy. Monomer conversions were calculated using ¹H NMR spectroscopy and a general decrease was found with increasing VPA content. Titration studies demonstrated an increase in the degree of dissociation as a function of VPA in the copolymer. However, a VPA content <i>ca</i>. 30 mol % was found to be the optimum for calcium chelation, suggesting that this composition is the most promising for biomaterials applications. Assessment of cell metabolic activity showed that PVPA-<i>co</i>-AA has no detrimental effect on cells, regardless of copolymer composition