Allyltin allyltributyltin

Platinum-catalyzed allylation of aldehydes with allyltin reagents was first reported in 1995.4S7 457b,483 483a Ar0matiC) aliphatic, a,/3-unsaturated aldehydes and even cyclohexanone undergo allylation with allyltributyltins in the presence of PtClgtPP 113)2 >n THF at room temperature or higher temperature (Equations (123) and (124)). Allylplatinum species are considered to be the active intermediates on the basis of related mechanistic studies on palladium catalysis. 

Allyltributyltin can be used in combinatorial radical allylation. Moreover, a polymer-supported reagent bearing an allyltin group was also developed and it can be used for the radical allylation of alkyl halides. 

Kosugi, M., Sasazawa, K., Shimizu, Y., Migita, T. Reactions of allyltin compounds. III. Allylation of aromatic halides with allyltributyltin in the presence of tetrakis(triphenylphosphine)palladium ° . Chem. Lett. 1977, 301-302. 

The second example in Table 5 shows the cyclization-carbonylation-allylation sequence, in which 5-hexenyl radical cyclization precedes CO trapping. Because of the nucleophilic nature of acyl radicals, in a mixed alkene system comprised of an electron deficient alkene and allyltin, they favor the electron deficient alkene first and the resulting product radical, which have an electrophilic character, and then smoothly add to allyltributyltin. This four-component coupling reaction provides a powerful radical cascade approach leading to y -functionalized, -unsaturated ketones, which are not readily accessible by other methods [52]. 

In Section 12.7.B, the Stille coupling reaction reacted a vinyl tin compound with a vinyl triflate, in the presence of palladium(O). Tetravalent tin complexes add to aldehydes and ketones, in the presence of a Lewis acid. Allyltin complexes are, by far, the most widely used of these compounds.297 a typical example is taken from the work of Keck, in which a chiral aldehyde (455) was treated with allyltributyltin, in the presence of various Lewis acids. S As shown in Table 12.19, a mixture of syn (456) and anti (457) products was obtained. The ratio of 456/457 was dependent on the structure of the R group in 455, the solvent and the Lewis acid.The anti product (457) was obtained by using the tert-butyldimethylsilyloxy derivative (sec. 7.3.A.i) of 455 with 2 equivalents of boron trifluoride in dichloromethane. The syn product is obtained preferentially when the benzyloxy derivative of 455 is used with titanium tetrachloride in dichloromethane.298... 

---