Application of Bulky NHC–Rhodium Complexes in Efficient S–Si and S–S Bond Forming Reactions

Abstract

The efficient and straightforward syntheses of silylthioethers and disulfides are presented. The synthetic methodologies are based on new rhodium complexes containing bulky N-heterocyclic carbene (NHC) ligands that turned out to be efficient catalysts in thiol and thiol–silane coupling reactions. These green protocols, which use easily accessible reagents, allow obtaining compounds containing S–Si and S–S bonds in solvent-free conditions. Additionally, preliminary tests on coupling of mono- and octahydro-substituted spherosilicates with selected thiols have proved to be very promising and showed that these catalytic systems can be used for the synthesis of a novel class of functionalized silsesquioxane derivatives.

Highly effective synthesis of mercapto-functionalized cubic silsesquioxanes as the first step in designing advanced nano-delivery systems

“…It is in agreement with the mechanism of this process described earlier by Arisawa's group 28 and our earlier paper. 29…”

“…Instruments and measurements Nuclear magnetic resonance (NMR) spectroscopy. 1 H NMR (402.6 MHz), 13 C NMR (101.2 MHz) and 29 Si NMR (79 MHz) spectra were recorded at 25 °C on Varian 400 and 300 MHz spectrometers in CDCl 3 solution. Chemical shifts are reported in ppm with reference to the residual solvent peaks for 1 H and 13 C NMR and to TMS for 29 Si NMR.…”

Immobilizing Triphenylamine with Photoredox Inert Sr2+ Forming Sr‐MOF with Controlled Electron Migration for Photocatalytic Oxidation of Thiols to Disulfides

“…[ 4‐7 ] The oxidation of thiols to disulfides can not only effectively solve the above problems, but also generate the high value‐added chemicals, displaying important environmental and industrial significance. [ 8‐10 ] Over the past decades, numerous methods have been reported for this process, [ 11‐16 ] among which the aerobic photocatalytic method, economical and eco‐friendly, is considered as the most promising. [ 17‐22 ] Compared with the traditional inorganic semiconductors or noble metal‐containing complex, the organic dyes show enhanced stability, easy modifications and reduced costs, thus garnering much attentions as a photocatalyst.…”

Rhodium catalysts with superbulky NHC ligands for the selective α-hydrothiolation of alkynes

“…12 Very recently, we disclosed the synthesis of catalysts III and IV bearing "superbulky" NHC ligands 13 and their application for the synthesis of disulfides and silylthioethers via thiol and thiol-silane coupling reactions. 14 Complexes V-VIII are new for science and were obtained according to the published procedures based on deprotonation appropriate imidazolium salt precursors with base in the presence of the commercially available [RhCl (cod)] 2 dimer. 15,16 Both approaches led to similar high yields but procedure proposed by Plenio is more favorable than the path described by Markó.…”