Synthesis and spectral characterization of medium ring distannacycloalkanes and their Lewis acid derivatives
作者:Dan Farah、Kamal Swami、Henry G. Kuivila
DOI:10.1016/0022-328x(92)83182-h
日期:1992.5
A study of the syntheses and some properties of several methyl substituted acyclic and cyclic bidentate organotin Lewis acids has been carried out. Of particular interest were cyclic species with 7-, 8-, 9- and 10-membered rings. The distannaalkanes and distannacycloalkanes were converted to the chlorides by chlorodemethylation with tin chlorides or mercuric chloride; this reaction was accompanied
已经进行了几种甲基取代的无环和环状二齿有机锡路易斯酸的合成和一些性质的研究。特别令人感兴趣的是具有7、8、9和10元环的环状物质。通过用氯化锡或氯化汞进行氯脱甲基化,将二烷烷和二烷环烷烃转化为氯化物。在某些情况下,该反应伴有环断裂。反过来,氯化物很容易转化为甲磺酸盐和三氟甲磺酸盐。1 H,13 C和119 Sn NMR和IR光谱数据用于获得有关结构,构象和聚集行为的信息。甲磺酸酯在氯仿中缔合。三叉戟不是。
Schmeisser, M.; Sartori, P.; Lippsmeier, B., Chemische Berichte, 1970, vol. 103, p. 868 - 879
作者:Schmeisser, M.、Sartori, P.、Lippsmeier, B.
DOI:——
日期:——
Reaction Mechanism of Transmetalation between Tetraorganostannanes and Platinum(II) Aryltriflate Complexes. Mechanistic Model for Stille Couplings
作者:Patrik Nilsson、Graeme Puxty、Ola F. Wendt
DOI:10.1021/om051021a
日期:2006.2.1
The complexes trans-[PtPh(OTf)(PMe2Ph)(2)] (1) and trans- [PtPh(OTf)(PPh3)(2)] (4) were synthesized from the corresponding chloro complexes in moderate yields. Complex I is slowly hydrolyzed in solution, giving the dinuclear hydroxo-bridged complex [Pt(mu-OH)(PMe2Ph)(2)](2)(CF3SO3)(2) (6), which was characterized by X-ray crystallography. In solution I and 4 undergo fast solvolysis to give the corresponding solvento cations. The reactivities of 1 and 4 with Me3SnPh were investigated in different solvents, and with 1 two products, trans- [PtPh2(PMe2Ph)(2)] (8) and cis-[PtPh2(PMe2Ph)(2)] (9), were always formed simultaneously. In THF an intermediate, trans- [PtPhMe(PMe2Ph)(2)] (14), was characterized on the path to 9. The kinetics for these reactions were evaluated numerically, and on the basis of rate laws, activation parameters, and reactivity trends a mechanism involving parallel equilibria to 8 and 9 with associative activation in all steps is proposed. In this mechanism the initial attack always takes place trans to the phenyl group, giving 8 and 14, respectively, via an open transition state. In a subsequent reaction, 14 reacts with another molecule of stannane, giving 9 as the final product via a cyclic transition state. Complex 4 gives exclusive formation of cis products: cis-[PtPhMe(PPh3)2] (12) and cis-[PtPh2(PPh3)2] (13). These results are discussed in relation to the reaction mechanism of the transmetalation step in the Stille reaction.