Bis-stannylated

Cyanamide can be stannylated under various conditions to give bis(stannyl)carbodiimides (224-227), and bis(stannyl)sulfurdiimides have been prepared from the reaction between S4N4 and trimethyldi-methylaminotin (228). 

A bis(stannyl)bis(phosphine)palladium complex has a twisted square planar structure and shows facile unimolecular twist-rotation.170... 

Bis(stannyl) dicarboxylates 10 and 11 showed usually tetracoordinated Sn atoms by IR and MOssbauer spectroscopy. See also Tables 5 and 8124. 

Bis(stannyl) tellurides yield aryl stannyl sulphides, as shown in reaction 33287. 

Reaction 42 shows the thermal rearrangement of bis(stannyl)diazomethanes into car-bodiimides, which can be further derivatized in many ways293. 

Benzyne, which is generated in situ from 2-(trimethylsilyl)phenyl triflate and KF, acts as an alkyne congener in distannation in the presence of palladium-/ r/-alkyl isocyanide complex.157 A variety of substituted benzyne derivatives inserts into the Sn-Sn bond to give l,2-bis(stannyl)benzenes (Equation (59)). The reaction fails to occur in the presence of other palladium catalysts such as Pd(PPh3)4. 

A distannation product of 2-butyne-l,4-diol oxidatively cyclizes to provide 3,4-bis(stannyl)furan, which then undergoes palladium-catalyzed cross-coupling with an aryl iodide to give 3,4-diarylfuran (Scheme 31).152,153... 

Bis(stannyl halides) of suitable geometry can act as bidentate Lewis acids. The compounds XPh2Sn(CI I2) SnPh2X, n= 1, 2, or 3, all form 1 1 adducts 29 with halide ion, preferentially chelating F rather than CL or BL. 

Reaction with BujSnCl and Me2PSiCl leads to the corresponding bis-stannylated and bis-silylated derivatives. ... 

Recently, isolable bis (triphenylstannyl)-substituted butatrienylidene complexes of manganese (13) were obtained by photolysis of alkynyl(triphenylstannyl)vinylidene complexes 12 (Scheme 3.9) [4, 5]. Treatment of the resulting bis(stannyl)butatrie-nylidene complexes 13 with tetrabutylammonium fluoride and water afforded the first characterizable butatrienylidene complexes (14) containing an unsubstituted [M=C=C=C=CH2] moiety (Scheme 3.9). In contrast to 13, complexes 14 were unstable above —5 °C and were therefore characterized in solution only by NMR spectroscopy at —40°C. Complexes 14 were also formed instantaneously when solutions of 12 were treated at — 30 °C with one equivalent of tetrabutylammonium fluoride. 

Prostaglandin endoperoxide, 2,3-dioxabicyclo[2.2.1]heptane, is obtained in 22% yield from the bistriflate of cw-l,3-cyclopentanediol and bis(stannyl) peroxide (eqnation 109). 

Bis(silyl) peroxide, preparation, 776-7 Bis(stannyl)peroxide, peroxide transfer reaction, 825... 

Stable 2-metalo-l,3-dithianes, such as stannanes or silanes, have also been prepared and reacted with electrophiles. Sequential alkylation of a 2,2-bis-stannyl-l,3-dithiane (i, BuLi, oxirane ii, BuLi, alkyl bromide) furnished the 2,2-dialkylated products in 40% yield (Equation 40) <1997JA2058>. 

The Stille coupling was also employed successfully to prepare covalently bound DNA base-pairs. 1,4-, and l,3-bis(stannyl)benzenes were used to connect purine units covalently through a phenylene linker. The reactions gave the desired products in mediocre yield, along the by-products of destannylation and mono-coupling (8.21.), The extension of the procedure to benzene-1,4-diboronic acid met with limited success.29... 

The treatment of o-bis(dimethylchlorostannyl)benzene 188 with fluoride or chloride ions gave in high yield a variety of /i-halo bis(stannyl)-containing complexes shown in Equation (12) <19980M5858>. The reaction is selective toward fluoride ions. Indeed, reaction of the starting complex 188 with fluoride ions leads only to the formation of the /i-fluoro product, while the /i-chloro product has not been detected. 

Synthesis, Reactivity, and Molecular Structure of Diphosphadisilacyclobutanes, Bis(stannyl)silyl-, and Bis(stannyl)germylphosphines... 

The reaction of the lithiated allylic carbanion derived from prenyl selenide with hexamethyldistannane did not lead to the mono a-stannylated allylic selenide but to a bis-stannylated compound. A consecutive Se/Sn exchange, without allylic isomerization, occurred [5] (Scheme 4). The reaction involves a selenophilic attack by Mej SnLi formed in the media. 

Bis(allyldibutylstannyl)naphthalene is highly effective for the selective allylation of aldehydes and ketones under neutral conditions (Eq. 112) [151]. Such a transformation is not realized with monostannane. The former reaction proceeds without any catalyst by taking advantage of the chelation-induced Lewis acidity of bidentate bis(stannyl) compounds. 

Bao et al. [178] have used several bis(stannyl) derivatives [2,5-bis(tributylstannyl) thiophene, l,4-bis(tributylstannyl)benzene, other l,4-bis(tributylstannyl)arenes, -bis(tri-butylstannyl)ethene] in the synthesis of functional polymers. 

Indeed, under photolytic conditions, bis(silyl)nitrilimine 9 isomerizes into bis(silyl)carbodiimide 14 in quantitative yield [3b]. More surprisingly, when a THF solution of diazo derivative 3 is stirred overnight at room temperature in the presence of a catalytic amount of tetrakis(triphenylphosphine) palladium, bis(stannyl)carbodiimide 15 is obtained in 90 % yield [16a] (Scheme 5). 

Stannylcyclopentadienyl radicals can be generated by photolysis of bis(stannyl)cyclo-pentadienes (equation 20-25), and are interesting because the ESR spectra provide in-... 

The reaction between YbU and K[Sn(CH2Bu)3] affords the diamagnetic ytterbium bis-stannyl derivative Yb(SnNep3)2(thf)2 (Nep = 2,2-dimethylpropyl) (33). On the other hand, the reaction of naphthaleneyt-... 

Similarly, non-racemic 2,3-epoxyaldehyde 38 displays a preference for Felkin-Anh addition with the bis-stannylated 39 yielding the highly functionalized epoxy-alcohol 40 (Scheme 5.2.9).i ... 

The palladium-catalyzed stannylation of allenes is an efficient approach for the preparation of y-substituted allylic stannanes. williams has recently described the bis-stannylation of 1-methoxymethyleneoxyallene yielding ( )-105, as well as the use of this functionalized stannane in allylation reactions. Pre-organization of the aldehyde by a-chelation provides for the synclinal transition state 108 leading to ant/,yyn-adduct 107 (Scheme 5.2.24). The mild conditions of the reaction retain the alkenylstannane of the product for further elaboration via cross-coupling reactions. 

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