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.

Development of structurally extended benzosiloxaboroles - synthesis and biological evaluation.

The synthesis of potassium 6-hydroxy-7-chloro-1,1-dimethyl-3,3-difluorobenzo-1,2,3-siloxaborolate 5b from readily available 4-bromo-2-chlorophenol was developed. This compound proved useful in various derivatizations resulting in a wide range of -functionalized benzosiloxaboroles. Reactions of 5b with selected substituted benzoyl chlorides gave rise to a series of respective derivatives with 6-benzoate side groups attached to the benzosiloxaborole core.

Heteroelement Analogues of Benzoxaborole and Related Ring Expanded Systems.

The review covers the chemistry of organoboron heterocycles structurally related to benzoxaboroles where one of the carbon atoms in a boracycle or a fused benzene ring is replaced by a heteroelement such as boron, silicon, tin, nitrogen, phosphorus, or iodine. Related ring expanded systems including those based on naphthalene and biphenyl cores are also described. The information on synthetic methodology as well as the basic structural and physicochemical characteristics of these emerging heterocycles is complemented by a presentation of their potential applications in organic synthesis and medicinal chemistry, the latter aspect being mostly focused on the promising antimicrobial activity of selected compounds.

Boronate Covalent and Hybrid Organic Frameworks Featuring P and P=O Lewis Base Sites.

Invited for the cover of this issue is Sergiusz Luliński and his co-workers from Warsaw University of Technology and University of Warsaw. The image depicts a journey through the interior of the porous Covalent Organic Framework containing phosphorus and boron centres with carbon dioxygen trapped inside an imagined cave. Read the full text of the article at 10.

Boronate Covalent and Hybrid Organic Frameworks Featuring P and P=O Lewis Base Sites.

Two covalent organic frameworks comprising Lewis basic P centers and Lewis acidic boron atoms were prepared by poly-condensation reactions of newly obtained tris(4-diisopropoxyborylphenyl)phosphine with 2,3,6,7,10,11-hexahydroxytriphenylene and 2,3,6,7-tetrahydroxy-9,10-dimethylanthracene. Obtained materials exhibit significant sorption of dihydrogen (100 cm  g at 1 bar at 77 K), methane (20 cm  g at 1 bar at 273 K) and carbon dioxide (50 cm  g at 1 bar at 273 K). They were exploited as solid-state ligands for coordination of Pd centers.