The Synthesis of the First Compound with Li-Si-Hg Bonding: [{Li(iPr3Si)2Si}2Hg]—a Source for the [Li(iPr3Si)2Si]. Radical

Abstract

Radikale Entwicklungen in der Silyllithium‐Chemie: Die Herstellung und Kristallstruktur von 1, der ersten Verbindung mit geminalen Hg‐Si‐Li‐Bindungen, werden beschrieben; 1 erhält man bei Reaktion von (iPr3Si)2SiH2 mit [(tBu)2Hg] und anschließender Lithiierung in THF. Durch Bestrahlung von 1 lässt sich [Li(iPr3Si)2Si]. 2 erzeugen, das erste EPR‐spektroskopisch detektierte Silylradikal mit einer α‐Si‐Li‐Bindung.

Radical Activation of SiH Bonds by Organozinc and Silylzinc Reagents: Synthesis of Geminal Dizinciosilanes and Zinciolithiosilanes

“…The above experiments and in particular the higher yields obtained in the presence of AIBN or t Bu 2 Hg (Scheme ) suggest that in analogy to R 2 Hg,2b, 3a,b R 2 Zn reacts with silanes by a radical mechanism.…”

“…9 Therefore, a single‐pot reaction leading to zinciosilanes by activation of SiH bonds has a great synthetic potential. Furthermore, in analogy to the synthesis of bismercuriosilanes,2b, 3a,b activation of dihydridosilanes by diorganozinc or disilylzinc compounds can lead, in a single‐step reaction, to new geminal dizinciosilanes. These interesting dimetallic reagents are potentially very attractive reagents, in a similar fashion to geminal dizinciomethanes, their organic analogues 10…”

“…Attempts to synthesize compounds having the Li‐C‐Zn connectivity failed as these compounds spontaneously yield four‐membered (CZn) 2 rings 16. Compound 3 is the second isolated geminal dimetallosilane having two different metals (the first is a mercury analogue of 3 2b).…”

Synthesis, Isolation, and Characterization of 1,1‐DiGrignard and 1,1‐Dizincio Silanes

“…Furthermore, only one example of a geminal dimetallosilane with two different metals, that is, a mercury bridged bis(silyllithium) species, was reported recently by our research group 1b. 3 This contrasts with the large variety of available geminal dimetallorganic reagents, which are very useful synthons in organic synthesis 4. In particular, diGrignard reagents and dizinc reagents are widely used in organic chemistry 5.…”

“…Geminal dimetallosilanes have already proved their great potential for the synthesis of novel silicon compounds 1. However, the variety and number of isolated geminal dimetallosilanes is very small 1–3. For example, all known geminal dimetallosilanes are alkali metal or mercury derivatives 2.…”