A Highly Enantiomerically Enriched Lithiosilane by Selective Cleavage of a Silicon–Phenyl Bond with Lithium

Abstract

On the path to chiral polysilanes, the synthesis and first structural characterization of the enantiomerically pure tetrasilane (R)‐3 was achieved. A new synthetic strategy was used, by which the cleavage of a silicon–phenyl bond in the substrate (R)‐1 generated as intermediate the enantiomerically enriched lithiosilane 2.

Carbon/Silicon Exchange at the Apex of Diphos‐ and Triphos‐Derived Ligands – More Than Just a Substitute?

“…While complex decomposition, especially that of low‐valent metal complexes, is not unusual, decomposition can also occur as a result of the initial reaction of the ligand backbone. Notably, Si–C bonds were exhaustively reported to be prone to cleavage under various conditions . As such, decomposition of ligands [R′ 2 Si(CH 2 PR′′ 2 ) 2 ] and [R′Si(CH 2 PR′′ 2 ) 3 ] has to be taken into account.…”

“…Notably, Si-C bonds were exhaustively reported to be prone to cleavage under various conditions. [17][18][19][20][21] As such, decomposition of ligands [R′ 2 Si(CH 2 PR′′ 2 ) 2 ] and [R′Si(CH 2 PR′′ 2 ) 3 ] has to be taken into account. Figure 1.…”

Recent Progress in Asymmetric Synthesis and Application of Difunctionalized Silicon‐Stereogenic Silanes

“…The comprehensive mechanistic knowledge about the stereospecificity of transformations of optically pure or enriched silicon‐stereogenic silanes with diverse nucleophiles was in large part achieved as a result of the fundamental investigations by Sommer and Corriu from the mid‐20th century onwards . The synthesis of highly enantiomerically enriched silyllithium compounds and their sometimes unusual stereochemical behavior in the course of conversions with different electrophiles has already been investigated in detail by Strohmann and co‐workers . Just recently there was also a study relating to the configurational stability of the silicon‐stereogenic center in Lewis‐base‐stabilized silylium ions .…”

(S)-1,2-Dimethyl-1,1,2-triphenyl-2-(4-piperidiniomethyl)disilane chloride

“…For details of lithiosilanes, see: Lickiss & Smith (1995); Sekiguchi et al (2000); Strohmann et al (2001Strohmann et al ( , 2006; Strohmann & Dä schlein (2008a,b); Tamao & Kawachi (1995). For enantiomerically enriched lithiosilanes, see: Colomer & Corriu (1976); Oestreich et al (2005); Omote et al (2000); Sommer & Mason (1965); Strohmann et al (2007). For the determination of the absolute configuration of the disilane as the mandelic acid adduct, see: Strohmann et al (2002).…”

“…Yet, as the synthetic pathways to functionalized lithiosilanes are extremly limited, only six highly enantiomerically enriched systems are known until today (Colomer & Corriu, 1976;Oestreich et al, 2005;Omote et al, 2000;Sommer & Mason, 1965;Strohmann et al, 2002;Strohmann et al, 2007). Thereby the Si-Si bond cleavage of aryl substituted disilanes with lithium proved to be a potential method for the preperation of these useful compounds.…”