Design of Highly Stable Iminophosphoranes as Recyclable Organocatalysts: Application to Asymmetric Chlorinations of Oxindoles

A new family of tartaric acid derived chiral iminophosphoranes has been developed as highly effective organocatalysts in the asymmetric chlorinations of 3-substituted oxindoles with a high level of enantioselectivity. Importantly, these catalysts are air- and moisture-stable. Recovery of the catalyst after simple chromatographic separation for reuse in the model reaction was achieved; the catalyst can be recycled six times without loss of any enantioselectivity. Several advantages of this catalytic process are high conversion after a very short reaction time at ambient temperature, low catalytic loading, and scale-up to multigram quantities with an excellent enantiomeric excess value of >99%, which meets the enantiomeric purity required for pharmaceutical purposes

Palladium Catalyzed C–I and Vicinal C–H Dual Activation of Diaryliodonium Salts for Diarylations: Synthesis of Triphenylenes

Using the synthetic strategy of palladium-catalyzed dual activation of both C–I and vicinal C–H bonds of diaryliodonium salts, we report an approach for direct diarylations of 2-bromobiphenyls or bromobenzenes. As a result, a wide range of triphenylenes with various substituents have been synthesized in good yields. These triphenylenes are expected to be employed in the “bottom-up” synthesis of functional aromatic molecules in material science

Palladium-Catalyzed Double-Suzuki–Miyaura Reactions Using Cyclic Dibenziodoniums: Synthesis of <i>o</i>‑Tetraaryls

Palladium-catalyzed double-Suzuki–Miyaura couplings between cyclic dibenziodoniums and arylboronic acids have been developed. As such, a wide range of <i>o</i>-tetraaryls were synthesized in good to excellent yields of 22–94%. Furthermore, tetraphenylene was prepared in 21% isolated yield with 2,2′-biphenyldiboronic acid by using this method

Palladium Catalyzed C–I and Vicinal C–H Dual Activation of Diaryliodonium Salts for Diarylation: Synthesis of 4,5-Benzocoumarins

With a strategy that makes use of palladium activation of both C–I and vicinal C–H bonds of diaryliodonium salts, an unprecedented approach in diarylation of coumarins was reported. As such, a wide range of 4,5-benzocoumarins with potential fluorescence properties have been synthesized in good yields. A series of experiments suggested that the formation of two carbon–carbon bonds proceeded in a synergetic manner

Synthesis of 2,3-Disubstituted <i>NH</i> Indoles via Rhodium(III)-Catalyzed C–H Activation of Arylnitrones and Coupling with Diazo Compounds

A rhodium-catalyzed intermolecular coupling between arylnitrones and diazo compounds by C–H activation/[4 + 1] annulation with a C­(N₂)–C­(acyl) bond cleavage is reported, and 2,3-disubstituted <i>NH</i> indoles are directly synthesized in up to a 94% yield. A variety of functional groups are applicable to this reaction to give the corresponding products with high selectivity. Compared to other previously reported Rh­(III)-catalyzed synthesis of homologous series, this method is simpler, more general, and more efficient

High-Performance Cable-Type Flexible Rechargeable Zn Battery Based on MnO₂@CNT Fiber Microelectrode

Nowadays, linear-shaped batteries have received increasing attentions because the unique one-dimensional architecture offers an omni-directional flexibility. We developed a cable-type flexible rechargeable Zn microbattery based on a microscale MnO₂@carbon nanotube fiberlike composite cathode and Zn wire anode. The Zn–MnO₂ cable microbattery exhibits a large specific capacity, good rate performance, and cyclic stability. The capacity of Zn–MnO₂ cable batteries are 322 and 290 mAh/g based on MnO₂ with aqueous and gel polymer electrolyte, corresponding to the specific energy of 437 and 360 Wh/kg, respectively. Besides, the Zn–MnO₂ cable battery shows excellent flexibility, which can be folded into arbitrary shapes without sacrificing electrochemical performance. Furthermore, we studied electrochemical properties of Zn–MnO₂ cable microbatteries with different Zn salt electrolytes, such as Zn salt with small anions (ZnSO₄ or ZnCl₂, etc.) and Zn salt with bulky anions (Zn­(CF₃SO₃)₂, etc.). With the merits of impressive electrochemical performance and flexibility, this first flexible rechargeable Zn–MnO₂ cable-like battery presents a new approach to develop high-performance power sources for portable and wearable electronics