Search

Water‐soluble organic cages are attractive targets for their molecular recognition and sensing features of biologically relevant molecules. Here, we have successfully designed and synthesized a pair of water‐soluble cationic cages employing click reaction as the fundamental step followed by the N‐methylation of the triazole rings. The rigid and shape‐persistent 3D hydrophobic cavity, positively charged surface, H‐bonding triazolium rings, and excellent water solubility empower both cages to exhibit a superior affinity and selectivity for binding with adenosine‐5'‐triphosphate (ATP) compared to cyclophanes and other macrocyclic receptors. Both cage molecules (PCC⋅Cl and BCC⋅Cl) can bind a highly emissive dye HPTS (8‐hydroxypyrene‐1,3,6‐trisulfonic acid trisodium salt) to form non‐fluorescent complexes. The addition of ATP resulted in the stronger cage⊂ATP complexes with the retention of HPTS emission upon its displacement. The resultant indicator‐displacement assay system can efficiently sense and quantify ATP in nanomolar detection limits in buffer solutions and human serum matrix. Spectroscopic and theoretical studies revealed the synergistic effect of π⋅⋅⋅π stacking interaction between the aromatic moiety of the cationic cages and the adenine moiety of ATP, as well as the electrostatic and hydrogen bonding interaction between the phosphate anion of ATP and triazole protons of cages, played the pivotal roles in the sensing process. [ABSTRACT FROM AUTHOR]

This work describes the palladium(II)‐catalyzed regioselective C8‐H olefination of 1‐naphthamides. Interestingly, naphthamide fused lactam 2,3‐dihydro‐1H‐benzo[de]isoquinolin‐1‐one derivatives were also synthesized in the case of a particular class of napthamides. This protocol was found well compatible with a diverse range of acrylates and styrenes leading to product formation in good yields along with a wide functional group tolerance. The developed strategy was further applied to the synthesis of different drug derivatives. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of cofacial organic cage molecules containing aggregation‐induced emissive (AIE) luminogens (AIEgens) through four‐fold Cu(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) "click" reactions. The shorter AIEgen, tetraphenylethylene (TPE), afforded two orientational isomers (TPE‐CC‐1A and TPE‐CC‐1B). The longer AIEgen, tetrabiphenylethylene (TBPE), afforded a single isomer (TBPE‐CC‐2). The click reaction employed is irreversible, yet it yielded remarkable four‐fold click products above 40 %. The phenyl rings around the ethylene core generate propeller‐shaped chirality owing to their orientation, which influences the chirality of the resulting cages. The shorter cages are a mixture of PP/MM isomers, while the longer ones are a mixture of PM/MP isomers, as evidenced by their x‐ray structures. The newly synthesized cage molecules are emissive even in dilute solutions (THF) and exhibit enhanced AIE upon the addition of water. The aggregated cage molecules in aqueous solution exhibit turn‐off emission sensing of nitroaromatic explosives, with selectivity to picric acid in the 25–38 nanomolar detection range. [ABSTRACT FROM AUTHOR]

Chiral self‐sorting during the formation of cage‐like molecules continues to fascinate and advance our understanding of the phenomenon in general. Herein, we report the chiral self‐sorting in the Pd6L12‐type metal‐organic cages. When a racemic mixture of axially chiral bis‐pyridyl ligands undergo coordination‐driven self‐assembly with Pd(II) ions to form Pd6L12‐type cages, the system has the option of chiral self‐sorting to afford any of at least 70 pairs of (one homochiral and 69 heterochiral) enantiomers and 5 meso isomers or a statistical mixture of everything. However, the system resulted in diastereoselective self‐assembly through a high‐fidelity chiral social self‐sorting to form a racemic mixture of D3 symmetric heterochiral [Pd6(L6R/6S)12]12+/[Pd6(L6S/6R)12]12+ cages. [ABSTRACT FROM AUTHOR]