Nucleophilicity of Neutral versus Cationic Magnesium Silyl Compounds

作者：Yan KaKing; Upton Brianna M; Zhu Jing; Ellern Arkady; Sadow Aaron D^*

来源：Organometallics, 2013, 32(22): 6834-6843.

DOI：10.1021/om400447q

Charge and ancillary ligands affect the reactivity of monomeric tris(trimethylsilyl)silyl magnesium compounds. Diamine-coordinated (tmeda)-Mg{Si(SiMe3)(3)}Me (tmeda = tetramethylethylenediamine; 2-tmeda) and (dpe)Mg{Si(SiMe3)(3)}Me (dpe = 1,2-N,N-dipyrrolidenylethane; 2-dpe) are synthesized by salt elimination reactions of L2MgMeBr and KSi(SiMe3)(3). Compounds 2-tmeda or 2-dpe react with MeI or MeOTf to give MeSi(SiMe3)(3) as the product of Si-C bond formation. In contrast, 2-tmeda and 2-dpe undergo exclusively reaction at the magnesium methyl group with electrophiles such as Me3SiI, B(C6F5)(3), HB(C6F5)(2), and [Ph3C][B(C6F5)(4)]. These reactions provide a series of neutral, zwitterionic, and cationic magnesium silyl compounds, and from this series we have found that silyl group transfer is less effective with cationic magnesium compounds than neutral complexes.

• 出版日期2013-11-25