Molecular Structures of Enantiomerically-Pure (S)-2-(Triphenylsilyl)- and (S)-2-(Methyldiphenylsilyl)pyrrolidinium Salts

Abstract

Silyl-substituted pyrrolidines have gained increased interest for the design of new catalyst scaffolds. The molecular structures of four enantiomerically-pure 2-silylpyrrolidinium salts are reported.The perchlorate salts of (S)-2-(triphenylsilyl)pyrrolidine [(S)-1·HClO 4 ] and (S)-2-(methyldiphenylsilyl)pyrrolidine [(S)-2·HClO 4 ], the trifluoroacetate (S)-2·TFA, and the methanol-including hydrochloride (S)-1·HCl·MeOH were elucidated by X-ray crystallography and discussed in terms of hydrogen-bond interactions.

The crystal structure of the first ether solvate of hexaphenyldistannane [(Ph3Sn)2• 2 THF]

“…In the course of our studies on the structural behaviour of triphenyl-substituted group 14 elements Bauer and Strohmann, 2015;Bauer and Strohmann, 2017;, we already reported on the inclusion of pyrrolidine into triphenylsilanol-based hydrogen-bonded arrangements (Bauer and Strohmann, 2015). Recently, we reported the methanol solvate of enantiomerically pure (S)-2-(triphenylsilyl)pyrrolidinium chloride (Bauer and Strohmann, 2017) as a further crystal solvate in addition to the previously described chloroform-incorporating hydrochloride .…”

“…In the course of our studies on the structural behaviour of triphenyl-substituted group 14 elements Bauer and Strohmann, 2015;Bauer and Strohmann, 2017;, we already reported on the inclusion of pyrrolidine into triphenylsilanol-based hydrogen-bonded arrangements (Bauer and Strohmann, 2015). Recently, we reported the methanol solvate of enantiomerically pure (S)-2-(triphenylsilyl)pyrrolidinium chloride (Bauer and Strohmann, 2017) as a further crystal solvate in addition to the previously described chloroform-incorporating hydrochloride . Hexaphenylethane, the lightest representative within the group 14, is a hypothetical compound (Lewars, 2008) that has been the subject of intense research since its presumed discovery in 1900 (Gomberg, 1900a;Gomberg, 1900b), leading to a new conceptual understanding of the interplay between steric repulsion and noncovalent dispersive attraction (Rösel et al, 2017).…”

Crystal Structure and Hirshfeld Surface Analysis of Trimethoxy(1‐naphthyl)silane – Intermolecular Interactions in a One‐Component Single‐Crystalline Trimethoxysilane

“…[14] The knowledge which interactions are involved in the aggregation of small molecules in the solid state is therefore of great importance for the understanding of structure-forming processes and for the targeted construction of molecular crystalline frameworks. [15] In continuation of studies on crystal packing and intermolecular interactions in molecular crystals, [16] I became interested in a more thorough understanding of the structure-forming principles in molecular, crystalline methoxysilanes. However, given the importance of methoxysilanes, only little information on the solid state structures of methoxysilanes with more than one SiÀ OMe group is available.…”

Coordination Chemistry of Silicon

“…Reactions with organolithium or Grignard reagents and ruthenium-catalyzed alkoxylations were employed for the substitution of each functional group. Bauer and Strohmann provide the molecular structures of four enantiomerically pure 2-silylpyrrolidinium salts [21]. XRD analysis unveiled the structures of these compounds, and hydrogen-bond interactions were discussed.…”