Synthesis of Siloxane Derivatives of Phenylboronic Acids of Different Structures.

The synthesis of a storage-stable organosilicon modifier with a dioxaborolane-protecting group is described. Its high reactivity and selective anti-Markovnikov addition in hydrosilylation reactions to afford siloxanes of various structures are shown. The possibility of deprotection of both the initial modifier and its siloxane derivatives under mild conditions using water in yields up to 96% is demonstrated. The existence of an equilibrium between the organosilicon derivatives of phenylboronic acids and their cyclic six-membered boroxines was confirmed by 1H NMR spectroscopy and X-ray diffraction analysis data. The use of siloxane derivatives of phenylboronic acids in Suzuki-Miyaura and Chan-Lam cross-coupling reactions was studied. All synthesized compounds were characterized by NMR (1H, 11B, 13C, and 29Si), IR spectroscopy, and high-resolution mass spectrometry.

Polyborosiloxanes (PBS): Evolution of Approaches to the Synthesis and the Prospects of Their Application.

The mini-review deals with borosiloxanes as a class of organoelement compounds that comprise Si-O-B bonds, including individual compounds and polymeric structures. The borosiloxanes first synthesized in the 1950s using simple methods demonstrated very unusual properties but were hydrolytically unstable. However, in recent times, synthetic methods have changed significantly, which made it possible to synthesize borosiloxanes that are resistant to external factors, including atmospheric moisture. Borosiloxanes became important due to their unique properties. For example, borosiloxane liquids acquire a thixotropic behavior due to donor-acceptor interchain interactions. In addition, borosiloxanes are used to produce flame-retardant ceramics. An analysis of the literature sources shows that no review has yet been completed on the topic of borosiloxanes. Therefore, we decided that even a brief outlook of this area would be useful for researchers in this and related fields. Thus, the review shows the evolution of the synthesis methods and covers the studies on the properties of these unique molecules, the latest achievements in this field, and the prospects for their application.