Application of Thiol−Ene Chemistry to the Preparation of Carbosilane−Thioether Dendrimers

Abstract

The application of thiol-ene chemistry to the synthesis of new carbosilane-thioether dendrimers is presented in this work. The dendrimers are prepared in a divergent fashion starting with tetravinylsilane as a core, followed by a succession of alternating thiol-ene and Grignard reactions. Vinyl-terminated dendrimers up to the fifth generation were isolated in excellent yields (78-94%). Products were characterized by multinuclear NMR spectroscopy, dynamic light scattering, gel permeation chromatography, and MALDI-TOF mass spectrometry.

Ferrocene and Silicon-Containing Oxathiacrown Macrocycles and Linear Oligo-Oxathioethers Obtained via Thiol–Ene Chemistry of a Redox-Active Bifunctional Vinyldisiloxane

“…5e As mentioned above, thiol−ene reactions proceed via a freeradical-based mechanism, and these radicals can be generated from a specific thiol by thermo-or photoinitiation. However, although there are precedents in the literature of thiol−ene reactions with vinylsilanes, 13−20 examples of reactions involving ferrocene-containing monomers difunctionalized with Si−CH CH 2 groups do not exist. Therefore, we could not predict, in principle, which of the two methods of initiation would be the most appropriate in our case.…”

“…Once separated, the pure model compound 2 and the macrocyclic dimer 3 were thoroughly characterized by elemental analysis, 1 H, 13 C, and 29 Si NMR spectroscopy, and MALDI-TOF mass spectrometry. Figure 3 shows the 1 H NMR spectra of thiocarbosiloxanes 2 and 3 together with that of their divinyldisiloxane precursor 1.…”

“…In this context, remarkable research on thiol−vinylsilane reactions has been carried out by Son et al 13 Thus, hydrothiolation reactions of vinylsilanes have been studied for the synthesis of new carbosilane−thioether 14 and poly(amidoamine−organosilicon) 15 dendrimers, water-soluble dendritic molecules with potential biomedical applications, 16 polymeric materials, 17 polyhedral oligomeric silsesquioxanes (POSS), 18 or silicone gel materials, 19 among others. To the best of our knowledge, only a few studies of the thiol−vinylsilane reaction in the field of transition metal chemistry have been reported by Manners et al 20 As a continuation of our studies on the chemistry of ferrocenecontaining vinylsilanes, this contribution describes our recent results regarding the preparation of structurally new types of ferrocene-and sulfur-containing macrocyclic and linear carbosiloxanes.…”

Application of Thiol-ene “click” Chemistry to Preparation of Hyperbranched Polyurethane Acrylate Oligomers Containing Carboxyl Groups

“…The thiol-ene reaction is highly efficient, high yielding, and environmentally benign. [15][16][17] Introduction of hyperbranched structure into photosensitive resins could obtain oligomers with low viscosity and high functionality. Although some hyperbranched photosensitive resin has been developed, the hyperbranched polyurethane methacrylate oligomers containing carboxyl groups which have good compatibility with fillers and dyes has been little reported to our knowledge.…”

Orthogonal reactivity of thiols toward chlorovinylsilanes: selective thiol-ene chemistry

“…As part of our growing efforts to take advantage of this valuable synthetic tool in organosilicon chemistry, [13][14][15] we now report a new and highly chemoselective reaction in which chlorovinylsilanes react exclusively with thiol-terminated molecules via the thiol-ene reaction. Previous reports in the literature have shown that thiol-terminated compounds, which are inherently nucleophilic, react with chlorosilanes by displacing the chloride atom; 16,17 however, in the wide breadth of the current study, this was not the case.…”