1,2-Benzisothiazol-3(2H)-ones and 1,3,4-oxadiazoles individually have recently attracted considerable interest in drug discovery, including as antibacterial and antifungal agents. In this study, a series of functionalized 1,2-benzisothiazol-3(2H)-one - 1,3,4-oxadiazole hybrid derivatives were synthesized and subsequently screened against Dengue and West Nile virus proteases. Ten out of twenty-four compounds showed greater than 50% inhibition against DENV2 and WNV proteases ([I] = 10 μM). The IC50 values of compound 7n against DENV2 and WNV NS2B/NS3 were found to be 3.75 ± 0.06 and 4.22 ± 0.07 μM, respectively. The kinetics data support a competitive mode of inhibition by compound 7n. Molecular modeling studies were performed to delineate the putative binding mode of this series of compounds. This study reveals that the hybrid series arising from the linking of the two scaffolds provides a suitable platform for conducting a hit-to-lead optimization campaign via iterative structure-activity relationship studies, in vitro screening and X-ray crystallography.

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This report deals with the syntheses, structures, supramolecular interactions, and biomimetic catalytic activity of three new manganese(III) complexes (1–3) containing the tetrabromocatechol ligand. Three different amines were used, with the goal of introducing their protonated species into the crystal lattice as counter cations for the robust bis(tetrabromocatecholate) chelated manganese(III) anionic species. All these systems present interesting noncovalent interactions in their crystal packing, including hydrogen bonding, halogen bonding, π –stacking and anion–π interactions. The geometrical differences (octahedral vs square pyramidal) have been analyzed by means of DFT studies, revealing that the strong anion–π interaction of pyridine with the complex anion compensates for the absence of one apical methanol molecule in 3. All of the complexes exhibited leveling catalytic activity for aerobic oxidation of 3,5‐di‐tert‐butylcatechol. DFT calculations support the formation of a stable complex‐substrate intermediate through hydrogen bonding, thereby disclosing the origin of catecholase activity of these complex anions.

Two thallium scorpionate complexes: dihydrobis (3-phenyl-4-cyanopyrazolyl)boratothallium(I) (TlBp Ph,4CN ), C 20 H 14 BN 6 Tl and dihydrobis(3-tert-butyl-4-cyanopyrazolyl) boratothallium(I) (TlBp t-Bu,4CN ), C 16 H 22 BN 6 Tl have been prepared and characterized by X-ray diffraction. Both compounds crystallize in monoclinic space groups, TlBp Ph,4CN in P2 1 /n with a = 4.2039(3) Å , b = 26.2211(17) Å , c = 16.611(1) Å , b = 90.199(3)°, and TlBp t-Bu,4CN in P2 1 /c with a = 13.8578(5) Å , b = 9.6741(4) Å , c = 14.2790(5) Å , b = 95.141(2)°. The two complexes show similar structures with elongated metal-ligand bonds and intermolecular interactions between the metal ion and cyano substituents, allowing the potential construction of cyanobridged coordination polymers.