Alkaline and Alkaline Earth Silyl Compounds—Preparation and Structure

Determination of the Solution Acidity of Tris(trimethylsilyl)silane

“…To our best knowledge, this is the first example of a clean direct proton abstraction from a silane by a carbanion. Since the known number of synthetic methods for the preparation of silyl anions is quite limited, this reaction presents an interesting new method for the preparation of silyl anions. The synthetic utility of this reaction is now being examined, and it will be discussed in more detail elsewhere…”

“…While we were aware of these facts, we had to carry out the measurements with the silyllithium rather than for the silylcesium because the silylcesium compound is very difficult to prepare and crystallize 9e. For the same reason (Me 3 Si) 3 SiLi is the reagent used in most applications. ,− Shatenshtein et al, who measured the redistribution equilibrium occurring between CH acids and organolithium or organocesium compounds in dimethoxyethane, , found that cesium salts are usually more stable (i.e., less basic) than the lithium analogues by 0.2−1.0 p K units. , More recently, Streitwieser et al measured equilibrium constants for the dissociation in THF solution of the lithium and cesium salts of 11 hydrocarbons . These dissociation constants were than used to determine the relative free ion acidities of the corresponding hydrocarbons in THF.…”

“…Silyl anions are important reagents in synthesis, and they are probably involved in the formation and the degradation of polysilanes . Of contemporary interest is the branched “hypersilyl” anion, (Me 3 Si) 3 Si - , which was first prepared in situ, and later its lithium salt was isolated and characterized as a stable complex with tetrahydrofuran (THF), 9a,b with 1,2-dimethoxyethane (DME) 9c and with lithium diphospholide,9d as well as the noncomplexed dimer 9e.…”

“…The large steric requirements, the interesting electronic properties, and the solubility of its derivatives in organic solvents have made (Me 3 Si) 3 Si a popular ligand in main-group and transition-metal chemistry . We have used this anion to prepare novel stable silenes and have recently synthesized the longer homologues (Me 3 SiMe 2 Si) 3 SiLi 6k…”

Reactivity of Bromodilithiosilane to Naphthalene and Anthracene

“…Lithium derivatives of group 14 elements have been known for many decades . Although 1,1-dilithiosilanes (R 2 SiLi 2 ) are useful reagents for the synthesis of organosilicon species, little attention has been given to them due to the difficulties involved in doing their syntheses.…”