Reduction of Organosilicon Peroxides: Ring Contraction and Cyclodimerization

Dumbbell-Shaped, Graft and Bottlebrush Polymers with All-Siloxane Nature: Synthetic Methodology, Thermal, and Rheological Behavior

A methodology for synthesizing a wide range of dumbbell-shaped, graft and bottlebrush polymers with all-siloxane nature (without carbosilane linkers) is suggested. These macroarchitectures are synthesized from SiOH-containing compounds-silanol (Et₃ SiOH) and siloxanol dendrons of the first and second generations, with various peripheral substituents (Me or Et)-and from linear siloxanes comprising terminal and internal SiH groups by the Piers-Rubinsztajn reaction. Products and key building blocks are obtained in yields up to 95%. These polymers are heat and frost-resistant siloxanes. As it turns out, the product physical properties are determined not only by the macromolecular structure, the linear chain length, the size and frequency of branched pendant, but also by the type of peripheral substituents-Me or Et-in the pendant. Thus, the viscosity of the graft polymers with branched pendant groups comprising peripheral Me-groups is more than ≈3-5 fold lower than that of analogous polymers with peripheral Et-groups.

Ozone Oxidation of Silylalkene: Mechanistic Study and Application for the Synthesis of Silacarboxylic Acid Derivatives

The addition-type ozone oxidation of silylalkenes is a highly efficient reaction to provide synthetically versatile α-silylperoxy carbonyl compounds. To gain insight into the reaction mechanism, we performed a computational study, which revealed that the reaction proceeds via [1,2]-Brook rearrangement-type silyl migration of primary ozonide. In sharp contrast to the addition-type reactions, the ozone oxidation of α-alkoxysilylalkenes proceeds in a cleavage-type manner to afford excellent yields of silacarboxylic acid esters via the 1,3-cycloelimination of primary ozonide prior to 1,2-silyl migration.

ATRA-like alkylation–peroxidation of alkenes with trichloromethyl derivatives by the combination of tBuOOH and NEt3

This protocol provides a unique and innovative approach to the construction of α-tert-butylperoxy-β-dichloromethyl alkanes, employing CHCl₃ as an alkylating reagent to provide a –CHCl₂ group, and TBHP as an oxidant to provide an α-^tBuOO group.

Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes

We developed a direct vicinal difunctionalization of alkenes with iodine and TBHP at room temperature. This iodination and peroxidation in a one-pot synthesis produces 1-(tert-butylperoxy)-2-iodoethanes, which are inaccessible through conventional synthetic methods. This method generates multiple radical intermediates in situ and has excellent regioselectivity, a broad substrate scope and mild conditions. The iodine and peroxide groups of 1-(tert-butylperoxy)-2-iodoethanes have several potential applications and allow further chemical modifications, enabling the preparation of synthetically valuable molecules.