Radical‐Initiated Dismutation of Hydrosiloxanes by Catalytic Potassium‐Graphite. Issue 16 (2nd April 2019)

• Record Type: Journal Article
• Authors: Frogneux, Xavier; Pesesse, Antoine; Delacroix, Simon; Ribot, François; Carenco, Sophie
• Is Part Of: ChemCatChem. Volume 11:Issue 16(2019)
• Page Start: 3781
• Page End: 3785
• Publication Date: 2019-04-02
• Subjects: Potassium-graphite -- PMHS -- hydrosiloxane dismutation -- radical initiation -- carbonyl reduction; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201900172
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: Formation of higher‐value products from cheaper silicone precursors such as polymethylhydrosiloxane (PMHS) is a challenge for silicon chemistry. Here, we show that catalytic amount (<0.5 mol %) of potassium graphite (KC8 ) can be used as an efficient radical initiator for the cleavage of Si−O bonds of hydrosiloxanes. Methylsilane and dimethylsilane are quantitatively obtained from PMHS and TMDS (1, 1, 3, 3‐tetramethyldisiloxane), respectively. Taking advantage of the high reactivity of the newly formed silane, the reduction of carbonyl functionalities with KC8 in catalytic amount was further performed. Mechanistic investigations suggest that both the dismutation of the initial hydrosiloxane and the reduction of carbonyl derivatives by hydrosilylation are initiated with a radical pathway. Abstract : Activating silicon waste : using a catalytic amount of a strong electron donor as potassium‐graphite, PMHS undergoes dismutation into methylsilane via a radical pathway.