1,1,2,2-Tetramethyl-1,2-bis(phenylthiomethyl)disilane, a Flexible Ligand for the Construction of Macrocyclic, Mesocyclic, and Bridged Dithioether Complexes. Synthesis of the Bis-silylated Olefins<i>Z</i>-(PhSCH₂)Me₂SiC(H)C(Ar)SiMe₂(CH₂SPh) by Catalytic Activation of the Si−Si Bond

Abstract

The functionalized disilane (PhSCH 2 )Me 2 SiSiMe 2 (CH 2 SPh) ( 1 ) has been prepared and coordinated as a dithioether ligand on [PtCl 2 (PhCN) 2 ] to afford the fluxional seven-membered chelate complex cis -[PtCl 2 {(PhSCH 2 ) 2 Si 2 Me 4 }] ( 2a ). After metathesis reaction of 2a with NaI the diiodo derivative cis -[PtI 2 {(PhSCH 2 ) 2 Si 2 Me 4 }] ( 2b ) was obtained. Treatment of [Re(μ-Br)(CO) 3 THF] 2 with 1 equiv of 1 yields the bromo-bridged dinuclear complex fac -[{Re(μ-Br)(CO) 3 } 2 {μ-(PhSCH 2 ) 2 Si 2 Me 4 }] ( 5 ), which is spanned by 1 forming a 10-membered mesocycle. Addition of a further equivalent of 1 yields the dinuclear macrocyclic compound fac -[{ReBr(CO) 3 } 2 {μ-(PhSCH 2 ) 2 Si 2 Me 4 } 2 ] ( 4 ), forming a 14-membered ring system. The chloro-bridge of [RuCl(μ-Cl)(CO) 3 ] 2 is cleaved by 1 to give the dinuclear compound fac -[{RuCl 2 (CO) 3 } 2 {μ-(PhSCH 2 ) 2 Si 2 Me 4 }] ( 6 ), in which the two metal fragments are linked by the thioether functions. In the presence of catalytic amounts of Pd(OAc) 2 /CNR, the Si−Si bond of 1 is cleaved and addition across the triple bond of phenylacetylene or p -tolylacetylene affords the bis-silylated olefins Z -(PhSCH 2 )Me 2 SiC(H) C(Ar)SiMe 2 (CH 2 SPh) ( 7a Ar = Ph; 7b Ar = p -Tol). The new compounds have been studied by multinuclear NMR techniques; the crystal structures of 2a, 2b, 4, 5, 6, and 7a have been determined by X-ray diffraction studies.