Alkali‐Metal‐Catalyzed Cross‐Dehydrogenative Couplings of Hydrosilanes with Amines

Abstract

International audienceWe report the N−H/H−Si cross-dehydrogenative coupling (CDC) of hydrosilanes and amines with high conversion (>90 %) and chemoselectivity for the production of silazanes, using group 1 metal hexamethyldisilazides [MN(SiMe3)2] (M=Li, Na, K) as precatalysts under mild conditions. [KN(SiMe3)2] showed higher activity than the congeneric lithium and sodium salts. The catalyzed CDC reaction displays a broad substrate scope. Phenylsilane and diphenylsilane react with a number of amines under ambient conditions; more elevated temperature is required for triphenylsilane to undergo CDC reactions. The intermediate lithium complex [(THF)2Li-{N(SiHPh2)(Dipp)}] (1) has been isolated and characterized in an attempt to identify the operative reaction mechanism

Hypervalent Hydrosilicates Connected to Light Alkali Metal Amides: Synthesis, Structure, and Hydrosilylation Catalysis

“…The silylated amine Ph 2 HSi(Me 3 TACD) was isolated from the reaction mixture. It can be regarded as the dehydrocoupling product of H 2 SiPh 2 with the amine proligand (Me 3 TACD)H. As was observed for other alkali metal amides, catalytic amount of complex 3 catalyzed the dehydrocoupling of (Me 3 TACD)H with H 2 SiPh 2 to selectively give Ph 2 HSi(Me 3 TACD) and H 2 (Scheme and see the Supporting Information). Sodium complex 2 was catalytically active under identical conditions, whereas the lithium amide 1 showed no reactivity.…”

Catalytic Formation of Silicon–Heteroatom (N, P, O, S) Bonds

“…Next, the Carpentier group has presented very interesting examples of the disilazide‐mediated dehydrocoupling of silanes and amines . Simple, commercially available alkali disilazides (Li, N, K) and barium bis(silyl)amide, in addition to its complexes with iminoanilido ligands, can serve as extremely active catalysts.…”

N‐Silylation of Amines Mediated by Et3SiH/KOtBu

“…Several catalytic processes have been developed over the years to obtain compounds containing the Si−N bond. These include processes mediated by alkali metals and alkaline earth metals (such as Ba, Mg, Ca and Sr) transition metals (Rh, Zn, Ru), metal nanoparticles and main group compounds . Generating O−Si bonds by mild cross dehydrogenative methods has also been the focus of recent attention.…”