431040-90-3Relevant academic research and scientific papers
The cationic rearrangement of (3-hydroxy-1-propenyl)tris(trimethylsilyl)-silanes into (1-trimethylsilyl-2-propenyl)bis(trimethylsilyl)silanols - Experimental and theoretical studies
Schmohl, Kathleen,Wandschneider, Dirk,Reinke, Helmut,Heintz, Andreas,Oehme, Hartmut
, p. 597 - 601 (2002)
(3-Hydroxy-1-propenyl)tris (trimethylsilyl)silanes (Me3Si)3-SiCH=CHCR2OH (8b,c) (b: R = Me; c: R = Ph) undergo a rapid rearrangement involving a 1,2-Si,C migration of one trimethylsilyl group from the central silicon atom to a cationic neighboring carbon atom and a shift of the olefinic double bond, in the presence of acid, to afford (1-trimethylsilyl-2-propenyl)bis(trimethylsilyl)silanols (Me3Si)2Si(OH)CH-(SiMe3)CH=CR2 (13b,c). Treatment of 8b,c with sulfuric acid in methanol gives the methoxysilanes (Me3Si)2Si(OMe)CH-(SiMe3)CH=CR2 (14b,c). In a related reaction, 8b,c are converted by boron trifluoride into the fluorosilanes (Me3Si)2-SiFCH(SiMe3)CH=CR2 (15b,c). A possible mechanism of the isomerization reaction, involving the rearrangement of the silylcarbenium ions [(Me3Si)3SiCH=CHCR2]+ into the silylium ions [(Me3Si)2SiCH (SiMe3)CH=CR2]+, is proposed. This is supported by calculations, which indicate the higher stability of the silylium ion 10b compared with the isomeric silylcarbenium cation 9b. For 14c the results of an X-ray structural analysis are given.
