Highly Efficient Dehydrogenative Coupling of Hydrosilanes with Amines or Amides Using Supported Gold Nanoparticles

Abstract

Hydroxyapatite-supported gold nanoparticles (Au/HAP) can act as a highly active and reusable catalyst for the coupling of hydrosilanes with amines under mild conditions. Various silylamines can be selectively obtained from diverse combinations of equimolar amounts of hydrosilanes with amines including less reactive bulky hydrosilanes. This study also highlights the applicability of Au/HAP to the selective synthesis of silylamides through the coupling of hydrosilanes with amides, demonstrating the first example of an efficient heterogeneous catalyst. Moreover, Au/HAP shows high reusability and applicability for gram-scale synthesis.

Silicon–Nitrogen Bond Formation via Heterodehydrocoupling and Catalytic N‐Silylation

“…Gold nanoparticles supported on hydroxyapatite are efficient (89–98 %) at coupling tertiary silanes with primary and secondary amines with loadings low as 0.83 mol % [49] …”

“…Gold nanoparticles supported on hydroxyapatite are efficient (89-98 %) at coupling tertiary silanes with primary and secondary amines with loadingsl ow as 0.83 mol %. [49] Ts uchimotoa nd co-workers screened various Lewis acid salts and bases for the N-silylation of indoles,a nd found that Zn(OTf) 2 and C 5 H 5 Nf acilitated N-silylation with av ariety of substitutedi ndolesa nd tertiary silanes (Figure 7). [50] This is related to their 2017 study with Zn(OTf) 2 and C 5 H 5 Na sc atalyst for Nsilylationwith Ph 2 MeSiH.…”

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

“…Another approach to Si−N bond formation by dehydrogenative coupling is based on the reaction between hydrosilanes and amines in the presence of precious metal nanoparticles. Graphene‐supported palladium and hydroxyapatite‐supported gold nanoparticles are very active catalysts . In contrast to metal‐mediated dehydrocoupling, which installs a silyl group on the nitrogen atom, Greb et al.…”

“…It was noted in Section 2.1 (see Scheme , ref. ) that B(C 6 F 5 ) 3 can be used in the dehydrogenative coupling of silanes with anilines and carbazoles. In the case of indole derivatives, it leads to reduced indolines through an N‐silylation/[1,5] sigmatropic rearrangement pathway.…”

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.…”