Si-Sn bond

Evidence for such new anionic trichlorosilylation reactions based on hexachlorodisilane is now provided by the corresponding hexachlorodisilane cleavage of germyl- and stannylphosphanes 3 and 4. This type of reaction is a novel way to make Si-Ge and Si-Sn bonds under very mild conditions. 5 and 6 have been isolated in pure state, spectroscopic and analytical data confirm their composition. For the recovery of R2PMMe3 from R2PSiCl3, reasonable paths have been developed [2],... 

Insertion of palladium into the Si-Sn bond generates intermediate 428 that undergoes m-addition on the triple bond (Scheme 108). The resulting vinylpalladium 429 ensures the carbopalladation of the second triple bond followed by reductive elimination with retention of stereochemistry.376... 

Silylstannylation is also observed in the Pd(PPh3)4-catalyzed reaction of alkynes with disilanyl stannanes, in which both Si-Si and Si-Sn bonds are present. The alkynes undergo insertion into the Si-Sn bond, to regio-and stereoselectively yield (/8-disilanylalkenyl)stannanes [Eq. (25)].73 With terminal alkynes, the stannyl group adds regioselectively to the internal carbon atom. Aliphatic alkynes are not reactive in this system. 

The initial Pd(PPh3)4-catalyzed addition of the Si-Sn bond of Me3Si SnMe3 to 1,1-dimethylallene selectively places the silicon on the central allenic carbon, but no selectivity is observed for placement of the tin atom. However, heating the reaction mixture (90°C) in the presence of the same palladium catalyst results in an 80% preference for the regioisomer having the stannyl group on the less hindered carbon.69,723... 

In contrast to carbon-tin rings the differences between the 119Sn chemical shifts of five- and six-membered Si—Sn rings are much smaller, possibly due to the larger Si—Si and Si—Sn bond lengths, atomic radii and therefore to the larger bond angles. 

The driving force of these fluorinations is the weakness of the C — X (X = B. Si, Sn) bond, that facilitates ipso substitution of these functional groups by a fluorine atom in reactions with electrophilic fluorinating reagents and, in some cases, with elemental fluorine. 

Se-O bonds, 452 Se-P bonds, 452 Se-S bonds, 452 Se-Se bonds, 451 Se-Te bonds, 452 Selenium clusters/complexes anions, 1346 cations, 1341-1346 neutrals, 1341 Si-containing compounds C-H bonds, 100, 131, 133 C-O bonds, 344 N-C bonds, 418 N-H bonds, 377 O-H bonds, 261, 304 0-0 bonds, 315 Si-Br bonds, 465 Si-C bonds, 460-462 Si-Cl bonds, 464-465 Si-F bonds, 463 -464 Si-Ge bonds, 467 Si-H bonds, 455-459 Si-1 bonds, 465 Si-Mn bonds, 467 Si-N bonds, 463 Si-O bonds, 462-463 Si-P bonds, 466 Si-S bonds, 466 Si-Se bonds, 450,466 Si-Si bonds, 459-460 Si-Sn bonds, 467 Si-Te bonds, 466 Silicon neutral complexes anions, 1153 cations, 1147-1152 neutrals, 1140-1147 Sm-containing species neutrals, 623 -626 Sm clusters, 626 Sn-containing compounds 0-0 bonds, 315 Sn-Br bonds, 475-476 Sn-C bonds, 476-477 Sn-Cl bonds, 475 Sn-F bonds, 475 Sn-Ge bonds, 475 Sn-H bonds, 473-474 Sn-1 bonds, 476 Sn-O bonds, 477 Sn-Pb bonds, 475 Sn-S bonds, 477 Sn-Se bonds, 477 Sn-Si bonds, 467 Sn-Sn bonds, 474-475 Sn-Te bonds, 477 Sr-containing species neutrals, 591-593 Sr+ clusters, 593-595 Sulfates... 

The alternating magnesium electrode system is also applicable to the Si—Ge or Si—Sn bond formation (equations 62-64). 

The Si—Ge and Si—Sn bonds are remarkably stable, both thermally and chemically, especially when the organic substituents are aryl groups. Triphenyl( tri-phenylsilyl)germanium (m. p. 357-359°C), which does not decompose below 500°C, is not attacked by iodine in boiling trichloromethane, by oxygen in boiling xylene or by acetic acid at 140°C in a Carius tube. 

The Si—Sn bond of triphenyl(triphenylsilyl)tin (m.p. 280-286 °C) ist not broken in glacial acetic acid, although the phenyl residues are replaced stepwise by acyl residues, beginning with those on the tin atom [450] (Eq. 3.241) ... 

The use of MejSiSnBuj in these nickel-catalyzed coupling reactions of dienes with aldehydes results in the formation of stannylated cyclic product homoallylic alcohols. The reaction may proceed via the oxidative addition of Ni(0) into the Si-Sn bond [227]. Moderate chiral induction is observed in this reaction when a monodentate phosphine ligand is employed [228]. 

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