Synthesis of 1H-isoindoliums by electrophile-mediated cascade cyclization/iodination of propargylamine-based 1,6-diynes.

A highly regio- and chemoselective synthesis of 1H-isoindoliums through a facile and novel cascade cyclization reaction of propargylamine-based 1,6-diynes under mild conditions has been developed. Different functional groups were compatible under the optimized reaction conditions, giving the corresponding products in up to 94% yields. Upon treatment with a base, the alkyne moiety of 1H-isoindoliums could be further transformed to allenes in excellent yields.

Tm3+: Bi4Si3O12 crystal as a promising laser material near 2 µm: growth, spectroscopic properties and laser performance.

We report on the crystal growth, spectroscopic properties and laser performance of Tm3+-doped Bi4Si3O12 (BSO) crystal. The crystal was grown by the vertical Bridgeman method. The spectroscopic properties are investigated based on absorption and luminescence spectroscopy. Judd - Ofelt (JO) analysis is performed to calculate the spontaneous emission probabilities, branching ratio and the radiative lifetimes. The absorption spectrum, emission spectrum and gain cross-section spectra of Tm3+: BSO crystal are determined for the 2 µm transition. Luminescence decay kinetic of 3F4 upper level was analysed in detail. The continuous-wave 2 µm laser with a maximum output power of 650 mW and a slope efficiency of 29.7% is demonstrated for the first time. The beam quality factor (M2) of Tm3+: BSO laser was about 1.03 at the maximum output level.

Effect of Qizhitongluo capsule on lower limb rehabilitation after stroke: A randomized clinical trial.

BACKGROUND: An individual's level of lower limb motor function is associated with his or her disability level after stroke, and motor improvement may lead to a better prognosis and quality of life. Data from animal models show that Qizhitongluo (QZTL) capsule facilitates recovery after focal brain injury. We aimed to validate the efficacy and safety of the QZTL capsule for promoting lower limb motor recovery in poststroke patients. METHODS: In this randomized, multicenter, double-blind, placebo- and active-controlled trial from 13 sites in China, participants with ischemic stroke and Fugl-Meyer motor scale (FMMS) scores of <95 were eligible for inclusion. Patients were randomly assigned in a 2:1:1 ratio to the QZTL group, Naoxintong (NXT) group or placebo group for 12 weeks at 15-28 days after the onset of stroke. The primary outcome was the change in the Lower Limb FMMS (FMMS-LL) score from baseline over the 12-week intervention period. RESULTS: 622 participants were randomly assigned to the QZTL group (309), NXT group (159), or placebo group (154). The FMMS-LL score increased by 4.81 points (95 % CI, 4.27-5.35) in the QZTL group, by 3.77 points (95 % CI, 3.03-4.51) in the NXT group and by 3.00 points (95 % CI, 3.03-4.51) in the placebo group at week 12. The QZTL group showed significantly larger improvements compared with the placebo group at each interview from weeks 4-12 (difference, 0.89 [0.30,1.49] at week 4, P = 0.0032; difference, 1.83[1.01,2.66] at 90 days poststroke, P < 0.0001; difference, 1.81[0.88,2.74] at week 12, P = 0.0001). CONCLUSION: The QZTL capsule is an effective treatment for lower limb motor impairment. The finding indicates that the QZTL capsule may be used as a potential new strategy for stroke rehabilitation.

Highly Graphitized Porous Carbon-FeNi3 Fabricated from Oleic Acid for Advanced Lithium-Sulfur Batteries.

Improving the electrical conductivity of sulfur, suppressing shuttle/dissolution of polysulfide, and enhancing reaction kinetics in Li-S batteries are essential for practical applications. Here, for the first time, we have used inexpensive oleic acid as a single carbon source, and have added commercial SiO2 as a template to form a porous structure, whereas introducing Fe(NO3 )3 and Ni(NO3 )2 as catalysts to increase the degree of graphitization. Moreover, the dual metal salts Fe(NO3 )3 and Ni(NO3 )2 can also form FeNi3 alloy, and our results show that FeNi3 nanoparticles accelerate the kinetic conversion reactions of polysulfide. By virtue of the well-developed porous structure and high degree of graphitization, the highly graphitized porous carbon-FeNi3 (GPC-FeNi3 ) has high conductivity to ensure fast charge transfer, and the hierarchically porous structure facilitates ion diffusion and traps polysulfide. Thus, a GPC-FeNi3 /S cathode displays excellent electrochemical performance. At current rates of 0.2 and 1 C, a cathode of the GPC-FeNi3 /S composite with a sulfur content of 70 % delivers high initial discharge capacities of 1108 and 880 mA h g-1 , respectively, and retains reversible specific capacities of 850 mA h g-1 after 200 cycles at 0.2 C and 625 mA h g-1 after 400 cycles at 1 C.

Copper-Catalyzed Regioselective sp3 C-H Azidation of Alkyl Substituents of Indoles and Tetrahydrocarbazoles.

An efficient regioselective sp3 C-H azidation is developed using CuBr as the catalyst and Zhdankin azidoiodinane as the "N3" source. Under simple and mild reaction conditions, the azido group could be successfully incorporated into the sp3 C-H alkyl substituents of indoles and tetrahydrocarbazoles.

Regio- and stereospecific Friedel-Crafts alkylation of indoles with spiro-epoxyoxindoles.

A highly efficient strategy for the regio- and stereospecific Friedel-Crafts alkylation of indoles with spiro-epoxyoxindoles has been developed in the mixed solvents of HFIP/H2O (1 : 9) without the use of catalysts. This protocol provides an atomically economical, catalyst-free and simple route for the construction of synthetically useful 3-(3-indolyl)-oxindole-3-methanols in high yields. Starting from optically active spiro-epoxyoxindoles a variety of enantiospecific 3-(3-indolyl)-oxindole-3-methanols could be obtained in high yields with complete retention of enantioselectivity.

Ni3Sn2/nitrogen-doped graphene composite with chemisorption and electrocatalysis as advanced separator modifying material for lithium sulfur batteries.

Lithium-sulfur batteries have been widely studied because of their advantages of abundant reserves, environmental friendliness, low cost andhighspecific capacity. However, the volume expansionand the low electrical conductivity of sulfur, and the shuttle effect of polysulfides limit their application. Herein,wesynthesizea two-dimensional layered Ni3Sn2/nitrogen-doped graphene (NG) composite asseparator modifying material for lithium-sulfur batteries. The Ni3Sn2formed by dual metal salts Ni(NO3)2·6H2O and SnCl2·2H2O can adsorb polysulfide and catalyze its transformation to improve the electrochemical reaction kinetics. Moreover, the layered NG can not only disperse the Ni3Sn2particles, but alsoensure rapid electron transfer. Therefore, the lithium-sulfur battery with the Ni3Sn2/NG modified separator shows excellent electrochemical performance. At a current rate of 1 C, the lithium-sulfur battery with the Ni3Sn2/NG modified separator can provide a high initial discharge capacity of 1022.1 mAh g-1and maintain a reversible specific capacity of 758.3 mAh g-1after 400 cycles.

Hollow Boron-Doped Si/SiOx Nanospheres Embedded in the Vanadium Nitride/Nanopore-Assisted Carbon Conductive Network for Superior Lithium Storage.

SiOx-based anode materials with high capacity and outstanding cycling performance have gained numerous attentions. Nevertheless, the poor electrical conductivity and non-negligible volume change hinder their further application in Li-ion batteries. Herein, we propose a new strategy to construct a hollow nanosphere with boron-doped Si/SiOx decorated with vanadium nitride (VN) nanoparticles and embedded in a nitrogen-doped, porous, and partial graphitization carbon layer (B-Si/SiOx@VN/PC). Benefiting from such structural and compositional features, the B-Si/SiOx@VN/PC electrode exhibits a stable cycling capacity of 1237.1 mA h g-1 at a current density of 0.5 A g-1 with an appealing capacity retention of 87.0% after 300 cycles. Additionally, it delivers high-rate capabilities of 1139.4, 940.7, and 653.4 mA h g-1 at current densities of 2, 5, and 10 A g-1, respectively, and ranks among the best SiOx-based anode materials. The outstanding electrochemical performance can be ascribed to the following reasons: (1) its hollow structure makes the Li+ transportation length decreased. (2) The existing nanopores facilitate the Li+ insertion/desertion and accommodate the volume variation. (3) The nitrogen-doped partial graphitization carbon enhances the electrical conductivity and promotes the formation of stable solid electrolyte interface layers during the repetitive Li+ intercalation/extraction process.

Switchable Skeletal Rearrangement of Dihydroisobenzofuran Acetals with Indoles.

The switchable skeletal rearrangement for the construction of amino indanones and tetrahydroisoquinolones frameworks had been developed. In the presence of a chiral phosphoric acid catalyst, the reaction gave the amino indanones in high yields and good to excellent ee (85-98%), while the methoxyl substituent at the 5-position of dihydroisobenzofuran acetal selectively gave isoquinolinones products in good to excellent ee (46-98%). Furthermore, DFT calculations were performed to explain the regioselectivity of the switchable transformation pathways.