Iridium-catalyzed silylation of unactivated C–H bonds

Abstract

The functionalization of primary CeH bonds has been a longstanding challenge in catalysis. Our group has developed a series of silylations of primary CeH bonds that occur with site selectivity and diastereoselectivity resulting from an approach to run the reactions as intramolecular processes. These reactions have become practical by using an alcohol or amine as a docking site for a hydrosilyl group, thereby leading to intramolecular silylations of CeH bonds at positions dictated by the presence common functional groups in the reactants. Oxidation of the CeSi bond leads to the introduction of alcohol functionality at the position of the primary CeH bond of the reactant. The development, scope, and applications of these functionalization reactions is described in this minireview.

Enantioselective Silylation of Aliphatic C−H Bonds for the Synthesis of Silicon‐Stereogenic Dihydrobenzosiloles

“…The process is usually initiated by oxidative addition of the Si−H bond to the metal center, which delivers the metal atom to the proximal C−H bond site, allowing the selective C−H bond activation [2a, 4] . The Hartwig group have made leading efforts in this field, [2a,d, 5] and successfully developed two enantioselective processes for the silylation of unactivated C(sp 3 )−H bonds, enabling the construction of chiral carbon‐stereogenic centers (Scheme 1 a). [6] However, to the best of our knowledge, there is only one example reported by Takai and co‐workers, that achieved an asymmetric C(sp 3 )−H silylation toward silicon‐stereogenic center, producing a specific spirosilabiindane compound in moderate yield with 40 % enantiomeric excess ( ee ) (Scheme 1 a).…”

Recent advances in catalytic silylation of hydroxyl‐bearing compounds: A green technique for protection of alcohols using Si–O bond formations

“…As usually attached to the asymmetrically substituted carbon atom, the hydroxyl group can be regarded as the most fundamental functional group in organic chemistry. [27][28][29][30][31][32][33] Therefore, it is evident that a wide variety of approaches has been disclosed and also the enantioselective synthesis of alcohols can be regarded as an inherent one. [34] Although there are important advances in late-stage functionalization of complex molecules, protection of hydroxy groups is highly required during the succeeding steps.…”

Aufeinanderfolgende β,β′‐selektive C(sp3)‐H‐Silylierung von tertiären Aminen mit Dihydrosilanen katalysiert durch B(C6F5)3

“…Die Diarylsilane 2 b-e wiesen eine gute Reaktivität auf und lieferten die entsprechenden Produkte im gleichen Ausbeutebereich wie für 2 a gefunden (1 a!3 ab-ae; Tabelle 2, Nr. [1][2][3][4]. Mit dem sterisch gehinderten Dimesitylsilan (2 f) wurde keine Reaktion beobachtet (Tabelle 2, Nr.…”