Recyclable and convenient-to-handle Pt/ethylene glycol catalytic system-an approach to sustainable hydrosilylation

This study presents a highly efficient and simple recyclable catalytic system for heterophase hydrosilylation. This catalytic system consisting of a commercially available platinum precatalyst, namely K2PtCl4, and a cheap green solvent, namely ethylene glycol (EG), is easily prepared by dissolving K2PtCl4 in EG without employing ligands, additives, or inert atmosphere, at r.t. It was found that mononuclear Pt0-complex generated in the catalytic system is a single-atom catalyst. The method enables 36 recycles with quantitative yield in air at r.t. The reaction proceeds at a high rate even with small catalyst loadings. High values of TON (up to 105) and TOF (up to 106) were achieved. This approach is applicable to a wide range of unsaturated compounds, such as terminal or internal alkenes, alkynes, and alkyl-, phenyl-, and siloxy-containing hydrosilanes. Moreover, the heterophase catalytic system is suitable for synthesis of linear and cross-linked polyorganosiloxanes. In most cases, the reaction provides high yields (up to 95-99%) and selectivity. It gives mostly anti-Markovnikov products, which can be isolated from the catalytic system by simple decantation. The process is scalable to gram quantities. (c) 2023 Elsevier Inc. All rights reserved.

Automated summary

This study presents a highly efficient and simple recyclable catalytic system for heterophase hydrosilylation. The catalytic system consists of a commercially available platinum precatalyst, K2PtCl4, and a cheap green solvent, ethylene glycol (EG). The single-atom Pt0-complex generated in the catalytic system enables 36 recycles with quantitative yield in air at room temperature. The method is applicable to a wide range of unsaturated compounds and suitable for the synthesis of linear and cross-linked polyorganosiloxanes.