Synthesis of Tricyclic Laddersiloxane with Various Ring Sizes (Bat Siloxane)

New Janus Tricyclic Laddersiloxanes: Synthesis, Characterization, and Reactivity

The synthesis of four novel syn-type tricyclic laddersiloxanes bearing eight or six alkenyl groups is presented. These compounds possess reactive alkenyl groups on both the bridged and side silicon atoms, and their structures were determined through characterization using multinuclear 1D and 2D NMR spectroscopy, mass spectrometry, and elemental analysis techniques. To investigate their reactivity, the compounds were subjected to hydrosilylation using two different silanes, and the resulting fully hydrosilylated compounds were thoroughly analyzed. Remarkably, all the synthesized laddersiloxanes displayed high thermal stability, suggesting their potential as promising precursors for the development of new hybrid materials. Additionally, preliminary findings indicate the possibility of exploiting the reactivity difference between the alkenyl groups attached to the D- and T-unit silicon atoms for the synthesis of Janus molecules. These findings highlight the potential of the reported compounds as valuable building blocks in the construction of innovative materials.

The Use of the Thiol-Ene Addition Click Reaction in the Chemistry of Organosilicon Compounds: An Alternative or a Supplement to the Classical Hydrosilylation?

This review presents the main achievements in the use of the thiol-ene reaction in the chemistry of silicones. Works are considered, starting from monomers and ending with materials.The main advantages and disadvantages of this reaction are demonstrated using various examples. A critical analysis of the use of this reaction is made in comparison with the hydrosilylation reaction.

Well-defined cyclic silanol derivatives

Cyclic silanol derivatives (CSDs), possessing siloxane rings consisting of T-unit silicon and oxygen atoms, are considered efficient precursors for the preparation of versatile well-defined building blocks of hybrid materials such as cyclic, cage- or ladder-type SQs. This review provides an outline of the main synthetic routes to numerous stereoregular CSDs with different sizes of siloxane rings since the first example of CSDs reported by Brown et al. in 1965. The typical reaction conditions and chemical shifts of ²⁹Si NMR of all mentioned CSDs in this review are summarized in tables and schemes to recapitulate the state of the art. The synthesis of all-cis-cyclotetrasiloxanes (T₄), the most investigated CSDs, and their functionalization by different organic reactions to access various all-cis-T₄ with functional groups are methodically presented. Moreover, the potential of CSDs in multiple application fields is discussed to show the possible research directions of this family of compounds in the future.

Vinyl-Functionalized Janus Ring Siloxane: Potential Precursors to Hybrid Functional Materials

A vinyl-functionalized all-cis-tetrasiloxycyclotetrasiloxane [ViSi(OSiMe2H)O]4 (Vi = vinyl group) Janus precursor was prepared from potassium cyclotetrasiloxane silanolate. The Janus precursor was selectively modified at its dimethylhydrosilyl groups [-SiMe2H] via the Piers-Rubinsztajn reaction to obtain a family of new tetravinyl-substituted Janus rings [ViSi(OR')O]4 containing various functional groups in moderate yields. Remarkably, the tetravinyl groups on the structure remained intact after modification by the Piers-Rubinsztajn reaction. Since these synthesized compounds possess multiple functional groups (up to eight per molecule), they are potential precursors for advanced hybrid organic-inorganic functional materials.