Tandem Si–Si and Si–H Activation of 1,1,2,2-Tetramethyldisilane by Gold Nanoparticles in Its Reaction with Alkynes: Synthesis of Substituted 1,4-Disila-2,5-cyclohexadienes

Abstract

The Au/TiO 2 -catalyzed reaction between 1,1,2,2-tetramethyldisilane and terminal alkynes yields substituted 1,4-disila-2,5-cyclohexadienes (1,1,4,4-tetramethyl-1,4dihydro-1,4-disilines) in moderate to good yields. The reaction proceeds via initial Si−Si activation of disilane by gold nanoparticles to form with alkynes isolable cis-1,2-disilyl adducts (cis-1,2-bis(dimethylsilyl)ethenes), which, under the reaction conditions, undergo a Au-catalyzed dehydrogenative cycloaddition to a second alkyne molecule, forming the final cycloadducts.

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

“…[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.…”

Recent Progress in the Transition‐Metal‐Catalyzed Activation of Si−Si Bonds To Form C−Si Bonds

“…The reaction tolerates a variety of functionalities, such as esters, halogens, and cyclopropane groups (Scheme ). Similar gold‐nanoparticle‐mediated catalysis has allowed the authors to achieve the tandem activation of Si−Si and Si−H bonds in 1,1,2,2‐tetramethyldisilane (Scheme ) . The predominant products are six‐membered 1,4‐disila‐2,5‐cyclohexadienes 2 , which show moderate regioselectivity.…”

“…Similarg oldnanoparticle-mediated catalysis has allowed the authors to achieve the tandema ctivation of SiÀSi and SiÀHb onds in 1,1,2,2-tetramethyldisilane (Scheme3). [6] The predominant products are six-membered 1,4-disila-2,5-cyclohexadienes 2, which show moderate regioselectivity.M inor regioisomers 2' are disfavored, probablyb ecause of steric repulsion between one of the silyl groups and the two Rg roups.…”

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

“…These types of compounds were recently recognized as important building blocks for the design of cross‐hyperconjugated molecules . Analogous dimethylsilyl‐substituted compounds were recently synthesized in our laboratory by using an alternative approach involving the Au/TiO 2 ‐catalyzed reaction of alkynes with 1,1,2,2‐tetramethyldisilane in a similar relative ratio of 2,5‐disubstituted/2,6‐disubstituted ones …”

“…[21] Analogous dimethylsilyl-substituted compounds were recently synthesized in our laboratory by using an alternative approach involving the Au/TiO 2 -catalyzed reaction of alkynes with 1,1,2,2-tetramethyldisilane in as imilar relative ratio of 2,5-disubstituted/2,6-disubstituted ones. [22] In conclusion, we presented herein am ethod for the direct cis-1,2-dehydrogenative disilylationo fa lkynes with dihydrosilanes (R 2 SiH 2 )c atalyzed by supportedA un anoparticles on TiO 2 under very mild conditions. It was postulated that the reactive speciesa re Au n -nanoparticle-tethered silyl groups, R 2 HSiÀAu n ÀSiHR 2 .T he disilyl adducts containing two SiÀH functionalities could be further functionalized in aone-pot procedure by the same catalyst to form either 2,5-dihydro-1,2,5oxadisiloles from the reaction with H 2 Oo r1 ,4-disila-2,5-cyclohexadienes from the reaction with an additional alkyne molecule.…”