Pentacoordinate hydridosilicates: synthesis and some aspects of their reactivity

• Published in: Organometallics Vol. 10; no. 7; pp. 2297 - 2303
• Main Authors: Corriu, Robert J. P, Guerin, Christian, Henner, Bernard, Wang, Qunjie
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.07.1991; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Exact sciences and technology; Organic chemistry; Organometalloidal and organometallic compounds; Physical Sciences; Preparations and properties; Science & Technology; Si derivatives; ELECTRON-TRANSFER; PENTA-COORDINATED MOLECULES; CARBONYL-COMPOUNDS; SELECTIVE REDUCTION; ORGANO-SILICON COMPOUNDS; NUCLEOPHILIC DISPLACEMENT; INTRAMOLECULAR LIGAND-EXCHANGE; SOLID-STATE STRUCTURES; F-19 NMR-SPECTROSCOPY; HEXACOORDINATED SILICON; Chemical reduction; Ester; Organic anion; Grignard reagent; Silicon Organic compounds; Aldehyde; Chemical reactivity; Ketone; Halocarbon; Organosilicon hydride; Electron donor
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om00053a035

Pentacoordinate hydridosilicates [HSi(OR)4]- (where R = Me, Et, n-Bu, i-Pr, Ph) as their K+ salts are obtained from reactions of trialkoxy- (or phenoxy-) silanes with the respective alkoxide (or phenoxide). Compared to HSi(OEt)3, [HSi(OEt)4]K exhibits a wide range of reactivities: (1) it undergoes facile displacement reactions at silicon with Grignard reagents and PhLi; (2) it acts as a base and leads to proton abstraction in the case of PhC = CH and Ph3CH; (3) it is able to reduce carbonyl compounds to the related alcohols; (4) it reacts with primary organic halides through an ionic mechanism (a SET process can be invoked in the case of benzylic halides (RX), which afford the dimer RR in addition to the alkane RH); (5) the ability to donate one electron is confirmed in reactions with oxidizing agents (Cu+, Ag+, Cp(CO)2Fe+) and by direct ESR observation of stable radical intermediates.