title: From an α-functionalized silicon-stereogenic N,O-silane to a monomeric and tetracoordinate tBuLi adduct with lithium-centered chirality.
abstract: Donor-functionalized silanes with stereogenic silicon centers are extremely rare. A convenient stereocontrolled route to a nitrogen-oxygen-functionalized silicon-chiral compound with an additional aminomethyl function is presented. This silane was directly achieved in stereochemically pure form by a simple nucleophilic substitution reaction. Owing to the unique asymmetry of this silane and the presence of three donor functions, the first monomeric butyllithium compound with lithium-centered chirality could be isolated; the configuration was assigned by X-ray crystallography. This [silane⋅ tBuLi] complex undergoes an unexpected deprotonation/stereospecific substitution sequence in toluene, leading to the development of a convenient one-pot synthesis of a functionalized silicon-chiral benzylsilane, which proceeds with inversion of configuration and complete preservation of the stereochemical integrity at silicon.
authors.affiliation: Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44227 Dortmund (Germany).
authors.forename: Jonathan O
authors.initials: JO
authors.lastname: Bauer
authors.forename: Carsten
authors.initials: C
authors.lastname: Strohmann
keywords: alkyllithium compounds; chirality; reactive intermediates; silanes; silicon