Syntheses and NMR study of [(2-dimethylaminomethyl)phenyl]vinylsilane derivatives and [(2-dimethylaminomethyl)phenyl]ethylsilane derivatives

Abstract

Various vinylsilanes, SiX(CHCH 2)(CH 3)[2-(CH 3) 2NCH 2C 6H 4], and ethylsilanes, SiX(CH 2CH 3)(CH 3)[2-(CH 3) 2NCH 2C 6H 4] [X=Cl ( 1); OMe ( 2); H ( 3); F ( 4); OSiMe 3 ( 5); NMe 2 ( 6); Me ( 7)], were synthesized in order to investigate the electronic effect of vinyl group on silicon atom having an intramolecular coordination arm. The magnitude of Δ δ (ethyl→vinyl for 29Si-NMR) of chlorosilane, 1, was the biggest one among 1– 7. The differences of 29Si chemical shifts between vinylsilanes and ethylsilanes increased in the following order: X=Me, NMe 2<H<OSiMe 3<OMe<F<Cl.