Enantioselective Radical-Type 1,2-Alkoxy-Phosphinoylation to Styrenes Catalyzed by Chiral Vanadyl Complexes.

A series of vanadyl complexes bearing 3-t-butyl-5-bromo, 3-aryl-5-bromo, 3,5-dihalo-, and benzo-fused N-salicylidene-tert-leucinates was examined as catalysts for 1,2-alkoxy-phosphinoylation of 4-, 3-, 3,4-, and 3,5-substituted styrene derivatives (including Me/t-Bu, Ph, OR, Cl/Br, OAc, NO2 , C(O)Me, CO2 Me, CN, and benzo-fused) with HP(O)Ph2 in the presence of t-BuOOH (TBHP) in a given alcohol or cosolvent with MeOH. The best scenario involved the use of 5 mol % 3-(2,5-dimethylphenyl)-5-Br (i.e., 3-DMP-5-Br) catalyst at 0 °C in MeOH. The desired catalytic cross coupling reactions proceeded smoothly with enantioselectivities of up to 95 % ee of (R)-configuration as confirmed by X-ray crystallographic analysis of several recrystallized products. The origin of enantiocontrol and homolytic substitution of the benzylic intermediates by vanadyl-bound methoxide and radical type catalytic mechanism were proposed.

Cinchona Alkaloid-Inspired Urea-Containing Autophagy Inhibitor Shows Single-Agent Anticancer Efficacy.

Autophagy is upregulated in response to metabolic stress, a hypoxic tumor microenvironment, and therapeutic stress in various cancers and mediates tumor progression and resistance to cancer therapy. Herein, we identified a cinchona alkaloid derivative containing urea (C1), which exhibited potential cytotoxicity and inhibited autophagy in hepatocellular carcinoma (HCC) cells. We showed that C1 not only induced apoptosis but also blocked autophagy in HCC cells, as indicated by the increased expression of LC3-II and p62, inhibition of autophagosome-lysosome fusion, and suppression of the Akt/mTOR/S6k pathway in the HCC cells. Finally, to improve its solubility and efficacy, we encapsulated C1 into PEGylated lipid-poly(lactic-co-glycolic acid) (PLGA) nanoscale drug carriers. Systemic administration of nanoscale C1 significantly suppressed primary tumor growth and prevented distant metastasis while maintaining a desirable safety profile. Our findings demonstrate that C1 combines autophagy modulation and apoptosis induction in a single molecule, making it a promising therapeutic option for HCC.

TiO2 nanocrystals decorated Z-schemed core-shell CdS-CdO nanorod arrays as high efficiency anodes for photoelectrochemical hydrogen generation.

TiO2 nanocrystals decorated core-shell CdS-CdO nanorod arrays, TiO2@CdO/CdS NR, were fabricated as high efficiency anodes for photoelctrochemical hydrogen generation. The novel sandwich heterostructure was constructed from first growth of CdS nanorod arrays on a fluorine doped tin oxide (FTO) substrate with a hydrothermal process, followed by in situ generation of CdO thin films of single digit nanometers from the CdS nanorod surfaces through thermal oxidation, and final decoration of TiO2 nanocrystals of 10-20 nm via a successive ionic layer absorption and reaction process. The core-shell CdS-CdO heterostructure possesses a Z-scheme band structure to enhance interfacial charge transfer, facilitating effective charge separation to suppress electron-hole recombination within CdS for much improved current density generation. The final decoration of TiO2 nanocrystals passivates surface defects and trap states of CdO, further suppressing surface charge recombination for even higher photovoltaic conversion efficiencies. The photoelectrochemical performances of the plain CdS nanorod array were significantly improved with the formation of the sandwich heterostructure, achieving a photo current density of 3.2 mA/cm2 at 1.23 V (vs. RHE), a 141% improvement over the plain CdS nanorod array and a 32% improvement over the CdO/CdS nanorod array.

Mixed NiO/NiCo2O4 Nanocrystals Grown from the Skeleton of a 3D Porous Nickel Network as Efficient Electrocatalysts for Oxygen Evolution Reactions.

Mixed NiO/NiCo2O4 nanocrystals grown in situ from the skeleton of a 3D porous nickel network (3DPNN) were prepared with a simple hydrothermal method followed by a low temperature calcination, exhibiting outstanding electrocatalytic efficiencies toward oxygen evolution reactions (OER). The 3DPNN was prepared with a novel leaven dough method and served as both the nickel source for growth of the mixed NiO/NiCo2O4 nanocrystals and the charge transport highway to accelerate the sluggish kinetics of the OER. The mixed NiO/NiCo2O4 nanocrystals exhibited pronounced synergistic effects to achieve a high mass activity of 200 A g-1 at the catalyst mass loading of 0.5 mg cm-2, largely outperforming the corresponding single component nanocrystal systems, NiO (5.87) and NiCo2O4 (9.35). The NiO/NiCo2O4@3DPNN composite electrocatalyst achieved a low overpotential of 264 mV at the current density of 10 mA cm-2 and 389 mV at the practically high current density of 250 mA cm-2, which compete favorably among the top tier of previously reported OER electrocatalysts. Moreover, it exhibited good stability even at the high current density of 250 mA cm-2, showing only 9.40% increase in working applied potential after a continuous 12 h operation. The present work demonstrates a new design for highly efficient OER catalysts with in situ growth of mixed oxide nanocrystals of pronounced synergistic effects.