α,ω-Oligosilyl Dianions and Their Application in the Synthesis of Homo- and Heterocyclosilanes

Abstract

The reactions of bridged tris(trimethylsilyl)silyl fragments with 2 molar equiv of potassium tert-butoxide allow the generation of R,ω-oligosilyl dianions (1a, 2a, 3a, 4a). Depending on the nature of the spacer between the oligosilyl units, these compounds can be used to generate either linear or cyclic derivatives. They are especially attractive for the formation of homoand heterocyclosilanes, as exemplified by the synthesis of sila-, stanna-, and zirconocenacyclosilanes. A linear bis(potassiumsilyl)acetylene (4a) was used to bridge two zirconocene units, (Cp 2 Zr(Cl)Si(SiMe 3 ) 2 CCSi(SiMe 3 ) 2 Zr(Cl)Cp 2 ) (11).

Transition metal compounds containing alkynylsilyl groups − complexes with a metal-silicon bond

“…1 The associated inverse reaction (inverse salt elimination) is a less common entry to silyl complexes as there is no generally applicable synthetic procedure for the required silyl anions (which are strong nucleophiles). Nevertheless, this route has been used for the synthesis of a zirconium alkynylsilyl complex [9]. 2 complexes.…”

“…Hence, cobalt alkynylsilyl compounds require an alternative synthetic route. Nucleophilic substitution, the second preeminent synthetic method for silyl complexes, has been reported so far only for a dinuclear iron complex (normal salt elimination: anionic metallate þ silyl halide) [8] and a zirconium oligosilyl compound (inverse salt elimination: metal halide þ silyl anion) [9]. In both syntheses strong nucleophiles (Fp À 1 or oligosilyl anion, resp.)…”

Incorporating Methyl and Phenyl Substituted Stannylene Units into Oligosilanes. The Influence on Optical Absorption Properties

“…Nevertheless dichlorostannane [(Me 3 Si) 3 Si] 2 SnCl 2 [37] was found to exhibit quite similar Si-Sn distances of 2.604(3) Å and the Si-Sn-Si angle of 142.5(1)° was even somewhat narrower than in 2 . For the structurally related cyclic compound (Me 2 Si) 2 [(Si(SiMe 3 ) 2 ] 2 SnPh 2 [44] the Si–Sn distances amount to 2.594(4) and 2.620(4) Å. For the related compounds (Me 3 Si) 3 SiSn i Pr 3 with only one tris(trimethylsilyl)silyl group and three isopropyl groups on tin and hexakis(trimethylsilyl)distannane even shorter Si-Sn distance of 2.573(4) and 2.5707(17) Å, respectively, were reported [45].…”

Organosilicon hypersilylchalcogenolates and related compounds

“…More recently, the reaction of Si(SiMe 3 ) 4 with KO t Bu developed by Marschner [40], has made KSi(SiMe 3 ) 3 and a variety of other oligosilanylpotassium species [41][42][43] readily available. As we have shown in a previous report [44], treatment of KSi(SiMe 3 ) 3 with elemental chalcogen (sulfur, selenium, tellurium) in THF yields the corresponding potassium hypersilylchalcogenolates K[ESi(SiMe 3 ) 3 ]:…”