Simple Synthesis of Oligosilyl-α,ω-dipotassium Compounds

Abstract

Multiply metalated oligosilanes: Treatment of bridged bis[tris(trimethylsilyl)silyl] compounds with two equivalents of potassium tert‐butoxide leads to the formation of 1,3‐ and 1,4‐dipotassium silanes [Eq. (1)]. Reaction of the latter with zirconocene dichloride and hafnocene dichloride, respectively, gives the corresponding metallacyclopentasilanes.

Polysilane Dendrimers

“…Recently, Marschner developed an easy and cheap synthetic method that gives access to a wide variety of potassium silanides via the selective cleavage of a Si-Si bond with KOBu t in THF [75]. Using this straightforward synthetic protocol, the potassium silanides K-18 [75], K-19 [76] and K-20 [41] (Figure 4) and also K-22 [77] (Figure 5) could be generated within a few hours in almost quantitative yields. Both, lithium and potassium silanide wings are used as strong nucleophiles in the selective formation of Si-Si bond required for the assembly of the final polysilane dendrimer.…”

“…An extension of this synthetic approach to oligosilanes that contain two Si-M functionalities is shown in Figure 5. Reaction of two equivalents of KOBu t with branched oligosilane 21 in THF at elevated temperatures gave access to the dipotassium disilanide K-23 in excellent yields [77]. Dilithiated disilanide Li-23 was obtained in modest overall yields in two steps [74].…”

“…Recently, the Krempner lab reported a synthetic strategy to even larger double-core polysilane dendrimers involving a convergent methodology [47]. Key to this approach is the generation of dimetalated oligosilane K-23 published by Marschner and coworker (see also Figure 5) [77], which in reactions with the chloro-functionalized dendrons 38 and 39 afforded the double-core dendrimers 55 (D-1312-6) and 56 (D-1313-6), respectively, in good yields ( Figure 14). In particular polysilane 56 is worth mentioning as it represents the largest dendritic polysilane prepared to date; it has a longest chain of 14 silicon atoms and a total of 32 silicon atoms.…”

Synthesis and characterization of 1,1-dihalogenated cyclopentasilanes

“…C 6 D 6 has been distilled over sodium and stored under nitrogen atmosphere. 2,5-di-potassium-2,5-bis(trimethylsilyl)-decamethylhexasilane [35] has been prepared following standard procedures. Trichlorosilane has been distilled prior to use.…”

Synthesis of a Fragment of Crystalline Silicon: Poly(Cyclosilane)

“…[19] 1,4-Functionalized cyclohexasilanes are a minor product (2 % yield) of unselective reductive coupling reactions. [21,22] Our approach to the functionalized cyclosilane synthetic challenge relies on the dual functionality of the phenylsilyl group (Scheme 1 c). [21,22] Our approach to the functionalized cyclosilane synthetic challenge relies on the dual functionality of the phenylsilyl group (Scheme 1 c).…”