Stereoelectronic effects of substituents at silicon on the hydrosilylation of 1-hexene catalysed by [RhCl(cod)(1-hexene)]

✍ Scribed by Wojciech Duczmal; Elzbieta Śliwińska; Beata Maciejewska; Bogdan Marciniec; Hieronim Maciejewski

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 465 KB
• Volume: 20
• Category: Article
• ISSN: 0340-4285
• DOI: 10.1007/bf00141512

✦ Synopsis

Trisubstituted silanes, HSiR 3 _,X, (R = Me or Et, X = C1, OEt, or Ph; n =0-3) oxidatively add to the complex [RhCl(cod

. Subsequent steps of hydrosilylation follow, i.e. cis-insertion of the alkene (u-a rearrangement) and then reductive elimination of the product, according to the general Chalk and Harrod scheme. A quantitative correlation between the second order rate constant, kl, of the oxidative addition (followed spectrophotometrically) at 20 ~ in benzene solution and the structure of the trisubstituted silane represented by stereoelectronic parameters Z, 0 and E" for the SiR3_,X . groups was established. The maximal hydrosilylation rate followed by g.l.c., is strongly retarded by highly electronegative substituents X on silicon and results from the elimination rate of the hydrosilylation product from (1) and the maximal concentration of (1) in solution.