Exploiting thiol-functionalized benzosiloxaboroles for achieving diverse substitution patterns - synthesis, characterization and biological evaluation of promising antibacterial agents.

Benzosiloxaboroles are an emerging class of medicinal agents possessing promising antimicrobial activity. Herein, the expedient synthesis of two novel thiol-functionalized benzosiloxaboroles 1e and 2e is reported. The presence of the SH group allowed for diverse structural modifications involving the thiol-Michael addition, oxidation, as well as nucleophilic substitution giving rise to a series of 27 new benzosiloxaboroles containing various polar functional groups, , carbonyl, ester, amide, imide, nitrile, sulfonyl and sulfonamide, and pendant heterocyclic rings.

Sumanene-carbazole conjugate with push-pull structure and its chemoreceptor application.

The first-of-its-kind tetra-substituted sumanene derivative, featuring the push-pull chromophore architecture, has been successfully designed. The inclusion of both strong electron-withdrawing (CF) and electron-donating (carbazole) moieties in this buckybowl compound has enhanced the charge transfer characteristics of the molecule. This enhancement was supported by ultraviolet-visible (UV-Vis) and emission spectra analyses along with density functional theory (DFT) calculations.

Ethynyl-substituted benzosiloxaboroles: the role of C(π)⋯B interactions in their crystal packing and use in Cu(i)-catalyzed 1,3-dipolar cycloaddition.

The synthesis and characterization of two novel 6-ethynyl-7-halogen substituted benzosiloxaboroles (Hal = F, Cl) is reported. The crystal structures of these compounds show a unique type of supramolecular assembly dictated by distinctive C(π)⋯B interactions resulting in the formation of columnar networks involving alternating ethynyl groups and boron atoms. The QTAIM, NBO and NCI analyses were performed in order to obtain a deeper quantitative insight into the nature of these interactions including energy and charge density distribution.

Synthesis and crystal structure of an iron triazole complex resulting from the unexpected ligand cleavage of a triazolium carbene precursor.

Typically reactions of N-heterocyclic carbenes with transition metals are straightforward and require a carbene salt, a base strong enough to deprotonate such a salt and a metal. Yet when carbene precursors are in the form of triazolium salts, reaction may not proceed as easily as expected. In our work, we intended to obtain a triazolylidene complex of iron(II) chloride, but due to the presence of small amounts of water in the tetrahydrofuran solvent used, bis(acetonitrile)tetrakis(1-benzyl-1H-1,2,4-triazole-κN)iron(II) μ-oxido-bis[trichloridoferrate(III)] acetonitrile disolvate, [Fe(CHN)(CHCN)][FeClO]·2CHCN - an interesting anion with a linear geometry of the O atom - was formed instead of the iron carbene complex.

Expanding the library of sumanene molecular receptors for caesium-selective potentiometric sensors.

This paper reports the synthesis and characterization of eight sumanene molecular receptors for the selective recognition of caesium cations (Cs). The sumanene derivatives differed in the number (from one to nine), type (electron donating or electron withdrawing) and method of the attachment (functionalization of sumanene at the benzylic or aromatic carbons) of substituents in the sumanene skeleton. The ultimate goal of this work was to investigate the prospective use of various sumanene derivatives in the design of Cs-selective potentiometric sensors, thus, expanding the library of sumanene receptors for such applications.