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 OlefinsZ-(PhSCH₂)Me₂SiC(H)C(Ar)SiMe₂(CH₂SPh) by Catalytic Activation of the Si−Si Bond

Abstract

The functionalized disilane (PhSCH2)Me2SiSiMe2(CH2SPh) (1) has been prepared and coordinated as a dithioether ligand on [PtCl2(PhCN)2] to afford the fluxional seven-membered chelate complex cis-[PtCl2{(PhSCH2)2Si2Me4}] (2a). After metathesis reaction of 2a with NaI the diiodo derivative cis-[PtI2{(PhSCH2)2Si2Me4}] (2b) was obtained. Treatment of [Re(μ-Br)(CO)3THF]2 with 1 equiv of 1 yields the bromo-bridged dinuclear complex fac-[{Re(μ-Br)(CO)3}2{μ-(PhSCH2)2Si2Me4}] (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-(PhSCH2)2Si2Me4}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-[{RuCl2(CO)3}2{μ-(PhSCH2)2Si2Me4}] (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-(PhSCH2)Me2SiC(H)C(Ar)SiMe2(CH2SPh) (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.

Photoinduced Rearrangement Reaction of 2-(Pentamethyldisilanyloxymethyl) phenylpentamethyldisilane

“…It is well known that disilane molecules having a siliconsilicon σ bond show unique properties in the photochemical [1][2][3][4] and thermal reactions 5 and in the transition metal catalyzed reactions [6][7][8][9][10][11][12][13][14] since the first reports on the unusual electronic spectra of aryldisilanes by Sakurai et al, 15 Gilman et al 16 and Hague et al 17 in 1964. In the context of our interest on the synthesis of silicon containing heterocyclic compounds by the photoreactions of ortho-substituted arylalkynyldisilanes [18][19][20][21][22][23][24][25][26][27][28][29] and aryldisilanes, 30,31 we have very recently reported on the photoreaction of (2-pentamethyldisilanyloxy)phenylpentamethyldisilane 32 in the presence of methanol or acetone affording a novel intramolecular photoproduct via silene intermediate.…”

Mono- and di-nuclear 2,3-diazabutadiene and 2-azabutadiene complexes of Rhenium(I): Syntheses, luminescence spectra and X-ray structures

“…The Re-N bond length of 2.266(3) Å lies in the same range as the mean Re-N value of 2a [2.263(4) Å], the C@N bond distance of the chelating azabutadiene ligand is markedly longer than that of 1b [1.335(5) Å vs. 1.299 (3) Å]. Probably due to the rigidity of the chelate ring, the dative Re-S bond of 2.464(1) Å is somewhat shorter than the averaged Re-S distance of about 2.50 Å encountered in other Re(I) complexes ligated by PhS-thioether donors [21][22][23]. Probably for the same reason, some p-conjugation between one phenyl [C(4) through C (9)] and the azadiene chain C(1)-N-C (2) The electronic absorption spectra of the di-nuclear complexes 2a and 2b display both one maximum at 267 nm with a shoulder around 360 nm.…”

Ethynyl[2.2]paracyclophanes and 4-isocyano[2.2]paracyclophane as ligands in organometallic chemistry

“…We have recently reported on the chemistry of 1,1,2,2-tetramethyl-1,2-bis(diphenylthiomethyl)disilane and exploited its potential for catalytic bis-silylation (double silylation) reactions [17]. In a similar manner, 5 was bissilylated using Pd(OAc) 2 /1,1,3,3-tetramethylbutylisocyanide as catalyst (Scheme 2), affording the olefinic dithioether 9 in 67% yield.…”

“…platinum bond occurred at ambient temperature upon addition of stoichiometric amounts of ligand 15 to a CH 2 Cl 2 solution of 16. The resulting complex [(OC) 4 Fe{l-dppm}PtCl 2 (CN-PCP)] (17) was isolated in high yields as a brownish solid. It shows poor solubility in hexane or Et 2 O, but is very soluble in THF or CH 2 Cl 2 .…”