Chiral Frustrated Lewis Pairs Catalyzed Highly Enantioselective Hydrosilylations of 1,2-Dicarbonyl Compounds

A highly enantioselective hydrosilylation of 1,2-dicarbonyl compounds was successfully realized for the first time utilizing the combination of tricyclohexylphosphine and chiral alkenylborane derived <i>in situ</i> from diyne as a frustrated Lewis pair catalyst. A variety of optically active α-hydroxy ketones and esters were obtained in 52–98% yields with 86–99% ee’s

Facile Development of Chiral Alkenylboranes from Chiral Diynes for Asymmetric Hydrogenation of Silyl Enol Ethers

A facile development of chiral alkenylboranes by the hydroboration of chiral diynes with Piers’ borane was successfully achieved for the first time. With the combination of the in situ generated chiral alkenylboranes and tri-<i>tert</i>-butylphosphine as frustrated Lewis pair catalysts, the metal-free asymmetric hydrogenation of silyl enol ethers was realized to furnish a wide range of optically active secondary alcohols in high yields and up to 99% ee

Organic–Inorganic Hybrids Composed of Keggin-Type [PMo₁₀V₂O₄₀]^5– Anions and Porphyrins: The Synthesis, Characterization, and Influence of Porphyrin Substituents on Optical Nonlinearities

In order to understand the influence of porphyrin substituents on the nonlinear optical properties of organic–inorganic hybrids composed of an anionic metal–oxygen cluster and a porphyrin cation, porphyrins bearing different functional groups (4-pyridyl, 4-hydroxyphenyl, and 3,4-dimethoxyphenyl) were chosen as prototypes to react with the well-known Keggin-type polyanion α-[PMo10V2O40]5–, which acted as an electron acceptor; this led to formation of three electrostatically bonded disalts with formal formulas of [C40H28N8]­[H4PMo10V2O40]2 (1), [C44H32N4O4]­[H4PMo10V2O40]2 (2), and [C52H48N4O8]­[H4PMo10V2O40]2 (3), respectively. These hybrids were systematically characterized by a variety of means. The nonlinear optical properties of these compounds were studied using the Z-scan technique, conducted with irradiation at λ = 532 nm with a 6 ns duration and a repetition rate of 10 Hz at focus E0 = 4.2 μJ. While all the hybrids showed an enhanced NLO response compared to their corresponding mother porphyrins, they also exhibited reverse saturation absorption, self-defocusing performance, and an enhancement of the second hyperpolarizability value γ in the order of γ­(1) 2) 3), which is parallel to the electron- or charge-donor ability of the functional groups on the porphyrin. Namely, the greater the electron-donor ability of functional groups on the porphyrin, the greater the NLO response

Enantioselective γ‑Addition-Driven Cascade of β,γ-Unsaturated Ketones by Ion-Pair Catalysis: Access to Chiral 1,3-Dioxolochroman Scaffolds

A highly enantioselective γ-addition-driven cascade of β,γ-unsaturated carbonyl compounds by bifunctional ion-pair catalysis has been developed. With this protocol, a range of functionalized chiral 1,3-dioxolochroman derivatives were prepared in high yields with superior stereoselectivities (>99% ee and >20:1 dr). The utility of this method was demonstrated by one-pot synthesis, scaled-up preparation, and facile transformation. Moreover, mechanistic investigations provided insights into the reaction pathway and the origin of chiral induction

Nitrogen-/Boron-Doped Carbon from Poplar Powder and Carbon Nanotube Composite as Electrode Material for Supercapacitors

This study presents a relatively easy method to use bioderived carbon material from poplar and carbon nanotubes as electrode materials in supercapacitors. After delignification, poplar powder was intercalated with acidized multiwalled carbon nanotubes, boric acid, and melamine. Subsequently, after carbonization and activation treatment, electrode materials in a supercapacitor exhibiting high electrochemical characteristics were prepared. The obtained multistage porous carbon material achieved a pore volume reaching 0.86 cm3 g–1 as well as a specific surface area reaching 1500.5 m2 g–1. The specific capacitance reached >432.31 F g–1, and the capacitance retention rate was still 95.7% after 3000 cycles of charge and discharge under a current density of 0.5 A g–1. A good power density was achieved by the symmetrical supercapacitor in 6 M KOH electrolyte (11.67 W h kg–1 at 300 W kg–1, 7.74 W h kg–1 at 1485 W kg–1) as well as a remarkable cycle stability (88.3% capacitance retention after 5000 cycles)

Rhodium-Catalyzed C(sp²)–O Cross Couplings of Diazo Quinones with Phenols to Construct Diaryl Ethers

The diaryl ether represents a prevalent structural motif found in numerous biologically active molecules. Herein, we describe a dirhodium-catalyzed C(sp2)–O cross coupling reaction between diazo quinones and phenols for the construction of diaryl ethers in moderate to high yields. The reaction proceeds under mild and neutral conditions and is tolerant of various functional groups. The synthetic method has been successfully applied to the concise synthesis of a Navl.7 inhibitor

Additional file 3 of Prevalence of sarcopenia in Chinese community-dwelling elderly: a systematic review

Additional file 3: Figure S2. The prevalence of sarcopenia in males by age group

Additional file 1 of Prevalence of sarcopenia in Chinese community-dwelling elderly: a systematic review

Additional file 1: Table S1. Characteristics of the included studies

Additional file 2 of Prevalence of sarcopenia in Chinese community-dwelling elderly: a systematic review

Additional file 2: Figure S1. Subgroup analysis of the prevalence of Sarcopenia by study year