Changhe Zhang

• The University of Queensland

Endosomal escape is a major bottleneck for efficient intracellular delivery of therapeutic cargoes, particularly for macromolecular biological cargoes such as peptides, proteins and nucleic acids. pH-responsive polymeric nanoparticles that can...

In this study, we report the design of a new guanylated, cholic-acid-based monomer (GM) to combat antimicrobial resistance. The microbial activity stems from the interfacial amphiphilicity of cholic acid, while guanidine shows a strong association with phosphate, which promotes binding to membrane phospholipids. The monomer showed strong antimicrob...

Stimuli-responsive nanoparticles have garnered significant interest for advanced materials design and development in areas such as biomedicine, sensing and energy. Recent studies have demonstrated that integrating multiple functionalities into a...

Polymer nanoparticles have generated significant interest as delivery systems for therapeutic cargo. Self-immolative polymers (SIPs) are an interesting category of materials for delivery applications, as the characteristic property of end-to-end depolymerization allows for the disintegration of the delivery system, facilitating a more effective rel...

While the addition of C1‐Lewis base enolates to carbonyls and related structures are well established, the related addition to thiocarbonyls compounds are unknown. Herein, we report a reaction cascade in which a C1‐pyridinium enolate undergos addition to dithioesters, trithiocarbonates and xanthates. The reaction provides access to a range of dihyd...

While the addition of C1‐Lewis base enolates to carbonyls and related structures are well established the related addition to thiocarbonyls compounds are unknown. Herein, we report a reaction cascade in which a C1‐pyridinium enolate undergo addition to dithioester, trithiocarbonates and xanthates. The reaction provides access to a range of dihydrot...

Inside Front Cover: Nanoparticles which undergo pH‐induced swelling upon cell internalization are synthesized with tunable swelling and buffering capacity. Previous research has suggested such materials endosomal escape through both the proton sponge and pH‐induced swelling mechanisms. However, in this work no endosomal escape was observed, suggest...

pH responsive nanoparticles have generated significant interest for use as drug delivery systems due to their potential for inducible release at low pH. The pH variation from the blood stream (pH 7.4) to intracellular compartments of cells called endosomes/lysosomes (pH < 5.0) has been of particular interest. However, one of the limitations with na...

Herein, we report the rational design of pH-responsive core-shell nanoparticles that incorporate a polyoxometalate (POM) cargo. Cobalt (III)-substituted borotungstate [BIIIW11O39CoIII]6- (POM) was selected due to its stability, low oxidizing power, and the ability to form kinetically inert coordinate bonds with the pyridyl functionality of the hydr...

While the enantioselective Rauhut–Currier reaction is established with bis(enone) substrates, it is yet to be reported with less electrophilic bis(enoate) substrates. By exploiting high‐nucleophilicity N‐heterocyclic carbenes, it is possible to achieve Rauhut–Currier reactions with these substrates. The reaction is demonstrated with a range of intr...

Bisenoate sind, vermutlich wegen ihrer geringen Elektrophilie, nur schlecht für enantioselektive Rauhut-Currier-Reaktionen geeignet. Die Verwendung nucleophiler N-heterocyclischer Carbene ermöglicht jetzt die ersten enantioselektiven Rauhut-Currier-Reaktionen dieser Verbindungen. Enantiomerenangereicherte Hydrocumarine wurden in drei Stufen aus kom...

Stimuli‐responsive nanoparticles have the potential to improve the delivery of therapeutics to a specific cell or region within the body. There are many stimuli that have shown potential for specific release of cargo, including variation of pH, redox potential, or the presence of enzymes. pH variation has generated significant interest for the synt...

The catalytic umpolung of imines remains an underdeveloped approach to reaction discovery. Herein we report an enantioselective aza‐Stetter reaction that proceeds via imine umpolung using N‐heterocyclic carbene catalysis. The reaction proceeds with high levels of enantioselectivity (all ≥96:4 er) and good generality (21 examples). Mechanistic studi...

The catalytic umpolung of imines remains an underdeveloped approach to reaction discovery. Herein we report an enantioselective aza‐Stetter reaction that proceeds via imine umpolung using N‐heterocyclic carbene catalysis. The reaction proceeds with high levels of enantioselectivity (all ≥96:4 er) and good generality (21 examples). Mechanistic studi...

Over the past decade, the α,β‐unsaturated acyl azolium(1) has been extensively examined in modern N‐heterocyclic carbene (NHC) organocatalysis. There are five general methods currently known to access the α,β‐unsaturated acyl azolium intermediates. In four of these methods, a redox approach is exploited that involves initial formation of an acyl an...

Herein we report the cycloisomerization of electron‐poor 1,5‐dienes via the β‐azolium ylide to give enantioenriched cyclopentenes. The reaction is mediated by a chiral N‐heterocyclic carbene (NHC) catalyst, exploits readily available substrates, has good generality (17 examples), and displays excellent enantioselectivity (mostly >94:6). Studies dem...

Herein we report the cycloisomerization of electron‐poor 1,5‐dienes via the β‐azolium ylide to give enantioenriched cyclopentenes. The reaction is mediated by a chiral N‐heterocyclic carbene (NHC) catalyst, exploits readily available substrates, has good generality (17 examples), and displays excellent enantioselectivity (mostly >94:6). Studies dem...

An enantioselective NHC (N-heterocyclic carbene) catalyzed synthesis of indenes from bifunctional α,β-unsaturated acyl fluorides and TMS enol ethers has been discovered. The reaction has broad generality (31 examples) and proceeds with high levels of enantioselectivity (most >92:8 er). Mechanistically the reaction likely occurs via a Michael/β-lact...

An enantioselective N-heterocyclic carbene (NHC)-catalyzed diene regenerative (4 + 2) annulation has been achieved through the use of highly nucleophilic morpholinone-derived catalysts. The reaction proceeds with good to excellent yields, high enantioselectivity (most >92% ee), and good diastereoselectivity (most >7:1). The generality of the reacti...

A reliable procedure for the synthesis of oxysulfonyl azides has been developed and applied to the three-component coupling reactions of azides, alkynes, and amines catalyzed homogeneously by CuI, which led to the formation of N-oxysulfonyl amidines with good yields. To fully evaluate the catalytic activity towards this coupling reaction, two coord...

The robustly porous metal-organic framework MOF-Cu2I2(BTTP4) (BTTP4 = benzene-1,3,5-triyl triisonicotinate) was shown to work as an efficiently heterogeneous catalyst for the three-component coupling of sulfonyl azides, alkynes, and amines, leading to the formation of N-sulfonyl amidines in good yields. MOF-Cu2I2(BTTP4) can be recycled by simple fi...