Supported Gold Nanoparticle-Catalyzed cis-Selective Disilylation of Terminal Alkynes by σ Disilanes

Abstract

Supported gold nanoparticles on metal oxides (1 mol %) catalyze for the first time the cis-selective disilylation of terminal alkynes by 1,2-disilanes in isolated yields up to 94%. It is likely that the reaction proceeds through oxidative insertion of the σ Si-Si bond of disilanes on gold followed by 1,2-addition to the alkyne.

Gold: Migratory Insertion at Au(I)

“…The here presented results give credit to the syn insertion pathway proposed occasionally for homogeneous [27] as well as heterogeneous [4,5,28] gold catalysts. The observed reactivity may have its origin in the particular electronic situation encountered in the silylgold complexes which differs remarkably compared to organogold complexes.…”

Gold‐Catalyzed Cross‐Coupling Reactions: An Overview of Design Strategies, Mechanistic Studies, and Applications

“…[383,385] Chem.E ur.J.2020, 26,1442 -1487 www.chemeurj.org 2019 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim Au/Pd alloy with equal amountso fA ua nd Pd is desirable for carrying out Ullmann coupling, decreasing the Pd content imparts it with better activityt oward the homocoupling of aryl boronic acids. [395] They reasonedb ased on previous reports that have shown the ability of Au I for activating the SiÀSi bond, [243,245] and the hydrolysis and alcoholysis of disilanes. [394] 7.4.…”

“…[394] 7.4. [395,397,398] Similarly,u nder ambient conditions, the cis-silaboration and diboration reactions could be carried out by using heterogeneous gold catalysis. Stratakis et al hypothesized that Au nanoparticles supported on TiO 2 could be utilized to activate the SiÀSi bond toward CÀSi bond-forming reactions.…”

Unique Reactivity of Dihydrosilanes under Catalysis by Supported Gold Nanoparticles: cis‐1,2‐Dehydrogenative Disilylation of Alkynes

“…To the best of our knowledge, there is only one relevant precedent of prevailing dehydrogenative 1,2‐disilylation relative to the typical hydrosilylation, in the Ni II ‐catalyzed addition of activated polychlorohydrosilanes to internal alkynes . Typically, the direct 1,2‐disilylation of alkynes can be achieved by activation of σ‐1,2‐disilanes either by Au/TiO 2 or another metal…”

“…Generally, the double cis ‐dehydrogenative addition to alkyl‐ or aryl‐substituted terminal alkynes took place at room temperature with very good selectivity (62–88 %) and within relatively short reaction times. Internal alkynes were unreactive, similar to that found with their attempted direct disilylation with 1,2‐disilanes in the presence of Au/TiO 2 . Note that, on the basis of the literature, disilyl adducts such as 1 a – 13 a can be formally synthesized by magnesiation of the corresponding cis ‐dibromoalkenes followed by quenching with Et 2 SiHCl .…”