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

Abstract

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.

Synthesis and characterization of sulfide/sulfone-containing 18-8-18-membered-ring ladder-type siloxanes

“…[23][24][25] Also, the B(C 6 F 5 ) 3 -catalyzed Piers-Rubinsztajn reaction, a transition metal-free approach to preparing wellcontrolled branched polysiloxanes, [26][27][28][29] has recently become a powerful tool for extending hydrosilyl-substituted all-cis-T 4 with methoxybenzene derivatives. [30][31][32] All-cis-T 4 with pyrene groups obtained recently by this method were found to be selective sensors for detection of gold ions and L-cysteine. 32 Our group previously found that B(C 6 F 5 ) 3 as a Lewis acid could catalyze intramolecular cyclization of the hydrosilyl-substituted all-cis-T 4 in the presence of excess water, and several tricyclic ladder-type SQs with varied siloxane side ring sizes (named as "Bat Siloxane" with 8-8-8 or 12-8-12-membered-ring system, Scheme 1) were synthesized.…”

“…23–25 Also, the B(C 6 F 5 ) 3 -catalyzed Piers–Rubinsztajn reaction, a transition metal-free approach to preparing well-controlled branched polysiloxanes, 26–29 has recently become a powerful tool for extending hydrosilyl-substituted all- cis -T 4 with methoxybenzene derivatives. 30–32 All- cis -T 4 with pyrene groups obtained recently by this method were found to be selective sensors for detection of gold ions and l -cysteine. 32…”

Well-defined cyclic silanol derivatives

“…Recently, Unno et al published the syntheses of a series of new Janus-type all-cis-T 4 117-130 starting from tetraphenyl-and tetravinyl-substituted Janus T 4 precursors with Si-H moieties through the Piers-Rubinsztajn reaction. 94,95 The Si-H moieties of the Janus precursors were extended to various aryl derivatives. These compounds are potential precursors for hybrid functional materials (Table 9).…”

Sequential hydrothiolation–hydrosilylation: a route to the creation of new organosilicon compounds with preset structures

“…1,2 The synthesis of siloxanes with a certain well-defined structure has recently become particularly relevant. 3 This approach enables the fine-tuning of the final properties of the end product by forming compounds with a preset structure.…”