Synthesis of an [(NHC)₂Pd(SiMe₃)₂] Complex and Catalytic cis‐Bis(silyl)ations of Alkynes with Unactivated Disilanes

Abstract

The novel complex cis-[(ITMe)2Pd(SiMe3)2 (ITMe=1,3,4,5-tetramethylimidazol-2-ylidene) has been synthesized by mild oxidative cleavage of Me3SiSiMe3 using [(ITMe)2Pd0]. The use of this complex as precatalyst for the cis-bis(silyl)ation of alkynes using unactivated disilanes is reported.

Tris(trichlorosilyl)tetrelide Anions and a Comparative Study of Their Donor Qualities

“…(ii) In the presence of soluble chloride salts, Si 2 Cl 6 undergoes heterolytic cleavage of its Si−Si bond to form SiCl 4 and the [SiCl 3 ] − anion, a versatile intermediate for the in situ generation of higher oligo‐ and organosilanes . (iii) The challenging activation of Si 2 Me 6 , on the other hand, requires the presence of powerful transition‐metal catalysts . Representatives of exhaustively Cl 3 Si‐substituted tetrelides are the methanide [(Cl 3 Si) 3 C] − ([ 1 ] − ) and the silanide [(Cl 3 Si) 3 Si] − ([ 2 ] − ) .…”

“…[14] (iii)The challenging activation of Si 2 Me 6 ,o nt he other hand, requirest he presence of powerful transition-metal catalysts. [15] Representatives of exhaustively Cl 3 Si-substituted tetrelides are the methanide [(Cl 3 Si) 3 C] À ([1] À ) [16][17][18] and the silanide[ (Cl 3 Si) 3 Si] À ([2] À ). [19,20] A correspondingu ncharged species A also exists ( Figure 1).…”

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

“…The disilylation of internal alkynes by using unactivated disilanes remains a longstanding challenge. Recently, Spencer, Navarro, and co‐workers have made an important breakthrough by developing [(NHC) 2 Pd(SiMe 3 ) 2 ] (NHC=N‐heterocyclic carbene) complex 7 as a precatalyst (Scheme ) . This complex can be synthesized as follows.…”

“…Recently,S pencer, Navarro, and co-workersh ave made an important breakthrough by developing [(NHC) 2 Pd(SiMe 3 ) 2 ]( NHC = N-heterocyclic carbene) complex 7 as ap recatalyst (Scheme 4). [7] This complex can be synthesized as follows.T hione 3 undergoes reductived esulfurization to give ylidene 4 in 86 %y ield. Reactiono f4 with [{Pd(methallyl)Cl} 2 ]l eads to the formationo f [(ITMe)Pd-(methallyl)Cl] 5 (ITMe = 1,3,4,5-tetramethylimidazol-2ylidene) in 95 %y ield.…”

One‐Step Synthesis of Siloxanes from the Direct Process Disilane Residue

“…Alternatively, AlCl 3 has also been discussed as catalyst for the HCl or H 2 supported disilane cleavage. Moreover, transition‐metal‐catalyzed conversions of disilanes into monosilanes in the presence of H 2 and HCl, in some cases in combination with amines or phosphines or with allyl chloride, are reported in the literature . Nevertheless, all processes listed lack the ability to fully convert highly methylated disilanes ( 3 – 5 ) to the respective monosilanes, but a few exceptions are reported .…”