Initiator‐Loaded Gold Nanocages as a Light‐Induced Free‐Radical Generator for Cancer Therapy

Tumor hypoxia greatly suppresses the therapeutic efficacy of photodynamic therapy (PDT), mainly because the generation of toxic reactive oxygen species (ROS) in PDT is highly oxygen‐dependent. In contrast to ROS, the generation of oxygen‐irrelevant free radicals is oxygen‐independent. A new therapeutic strategy based on the light‐induced generation of free radicals for cancer therapy is reported. Initiator‐loaded gold nanocages (AuNCs) as the free‐radical generator were synthesized. Under near‐infrared light (NIR) irradiation, the plasmonic heating effect of AuNCs can induce the decomposition of the initiator to generate alkyl radicals (R^.), which can elevate oxidative‐stress (OS) and cause DNA damages in cancer cells, and finally lead to apoptotic cell death under different oxygen tensions. As a proof of concept, this research opens up a new field to use various free radicals for cancer therapy.     

Die Reaktivdestillation: Moderne Trenn‐ und Reaktionstechniken

In a reactive distillation column, both the chemical conversion and the distillative separation of the product mixture are carried out simultaneously. Through this integrative strategy, chemical equilibrium limitations can be overcome, higher selectivities can be achieved and heat of reaction can be directly used for distillation. Moreover, azeotropic mixtures and mixtures of closely boiling components can be separated by reactive distillation. Increased process efficiency and reduction of investments and operational costs are the direct results of this approach.     

In‐Operando Mapping of pH Distribution in Electrochemical Processes

In aqueous electrochemical processes, the pH evolves spatially and temporally, and often dictates the process performance. Herein, a new method for the in‐operando monitoring of pH distribution in an electrochemical cell is demonstrated. A combination of pH‐sensitive fluorescent dyes, encompassing a wide pH range from ≈1.5 to 8.5, and rapid electrochemically coupled laser scanning confocal microscopy is used to observe pH changes in the cell. Using electrocoagulation as an example process, we show that the method provides new insights into the reaction mechanisms. The pH close to the aluminium electrode surface is influenced by the applied current density, hydrolysis of aluminium cations, and gas evolution. Through quantification of the pH at the anode, along with gas analysis, we find that hydrogen is evolved at the anode due to a non‐Faradaic chemical reaction. This leads to increased production of coagulant, which may open new routes to enhance the process performance. This method for in‐operando dynamic visualization of pH paves the way for studies of electrochemical processes, including other water treatment, electrosynthesis, and batteries.     

Enantioselective Aluminum‐Free Alkene Hydroarylations through C−H Activation by a Chiral Nickel/JoSPOphos Manifold

Highly enantioselective nickel‐catalyzed alkene endo‐hydroarylations were accomplished with full selectivity by organometallic C?H activation. The asymmetric assembly of chiral six‐membered scaffolds proved viable in the absence of pyrophoric organoaluminum reagents within an unprecedented nickel/JoSPOphos manifold.     

Borazine‐CF3− Adducts for Rapid,Room Temperature,and Broad Scope Trifluoromethylation

A fluoroform‐derived borazine CF₃⁻ transfer reagent is used to effect rapid nucleophilic reactions in the absence of additives, within minutes at 25 °C. Inorganic electrophiles spanning seven groups of the periodic table can be trifluoromethylated in high yield, including transition metals used for catalytic trifluoromethylation. Organic electrophiles included (hetero)arenes, enabling C−H and C−X trifluoromethylation reactions. Mechanistic analysis supports a dissociative mechanism for CF₃⁻ transfer, and cation modification afforded a reagent with enhanced stability.