Allyltin derivatives

Allylcyciohexanone, 42,14 Allyllithium, 41, 30 from allyltin derivatives, 41, 32 reaction with 4-methyl-2-pentanone, 41,30... 

A polymer-supported allyltin derivative was also reported to undergo a Lewis-acid-catalysed addition to benzaldehydes to give products such as l-phenylbut-3-en-l-ol and 1 -(p-bromophenyl)but-3-en-1 -ol154. 

Sugar allyltin derivatives are very useful synthetic intermediates. The most convenient and reliable method for their preparation is a so-called xanthate procedure. The first compound of this class was prepared in 1988 by Mortlock and Thomas [74]. 1,2-0-isopropylidene-D-glycer-aldehyde (80) was converted into allylic alcohol and further transformed into the corresponding xanthate 81. This compound underwent thermal [3,3] rearrangement into the dithiocarbon-ate 81a, which upon reaction with tri-n-butyltin hydride provided the final sugar allyltin 82 as a mixture of isomers with the E-one strongly predominating (O Scheme 35). 

Jarosz, S., Kozlowska, E. Synthesis and application of allyltin derivatives in organic chemistry. Pol. J. Chem. 1998, 72, 815-831. 

Allyl sulfones have been used in a large number of valuable syntheses, but notably in the synthesis of alkenes, dienes and polyenes. Thus a-alkylallyl tolyl sulfones afford terminal alkenes regioselectively when treated sequentially with 2 equiv. of tin hydride and concentrated hydrochloric acid (Scheme 117, entry Allyltin derivatives, which are intermediates in this transformation, can be isolated if the acidic treatment is omitted (Scheme 117, entry a). 

Table 6.3.2 Reactions of allyltin derivatives with DEAD in Et20 (half-lives of reactions for 0.0254 mol dm solutions)...

The effect of added LiC104 was studied with five allyltin derivatives in ether, under standard conditions." The results are given in Table 6.3.4. In pure ether, the yields of the studied compounds after 3 h were less than 5%. The yield for allyldi-n-butyltin chloride was equal to 30%. Illumination for a longer time led to decomposition. The addition of 4 mol dm of LiC104 produced a considerable increase in the yield of the reaction no cycladdition products were detected, and the ratio of the M-ene and H-ene reactions varied from ca. 1 1 for allyltricyclohexyltin to 1 0 for allyltriphenyltin. As observed with the azo enophiles, an increase in the polarity of the medium resulted in an increase in the overall rate of the reaction, and a chemoselectivity favoring the M-ene reaction. 

Table 6.3.4 Reaction of allyltin derivatives with singlet oxygen in 4 mol dm solution of UCIO4...

Jarosz, S., and Skora, S., A convenient route to enantiomerically pure highly oxygenated decalins from sugar allyltin derivatives. Tetrahedron Asymmetry. 11, 1433, 2000. 

Reaction of aldohexofuranose 5,6-diols with TPP/imidazole/l2 has afforded the corresponding 5,6-unsaturated derivatives, while elimination of HBr from the 6-bromo compound 23, followed by hydroboration, has generated the product 24 with the L-ido configuration (Scheme 4). Some sugar allyltin derivatives (e.g. 

Sugar allyltin derivatives, convenient precursors of dienoaldehydes such as compounds 31, have been obtained by Sr2 reaction of trialkyltin radicals with allylic thiocarbonates which were, in turn, produced by Wittig condensation followed by a 3 3 thermal rearrangement, as shown in Scheme 5. ... 

With allyltin derivatives a change of the relative configurations at the newly formed stereogenic centers is observed when the reaction, which is rather slow without a catalyst, is performed in the presence of BFs, apparently as a consequence of the now open transition state with BFj activation of the carbonyl group and the reaction not going via a cyclic, six-membered transition state as is usual. 

The (hydroxymethyl)allyl sulphones (137) react stereoselectively with tri-n-butyltin hydride in the presence of a radical initiator to give allyltin derivatives... 

It is quite remarkable that in most cases CH-acids are added without either primary transformation into enolate forms or even the addition of a base capable of in situ deprotonation. The reaction with CH-acids without prior deprotonation was described for non-aqueous media for the palladium-catalyzed allylation with allyltin derivatives [69], though the mechanism proposed is quite specific and requires the presence of an organotin compound. By adjusting this mechanism to the reaction in water, the process shown in Scheme 5.5 may be considered. 

It is widely appreciated that the 1,3-cycloaddition is a pericyclic reaction, which proceeds through a concerted mechanism. However, many other cycloaddition reactions do not perform via a concerted manner, which could be called formal cycloaddition reactions. Studer and coworkers reported the first examples of highly enantioselective formal [3-1-2] cycloadditions of allyltin derivatives 48 with 2-nitrosopyridine 49 to give substituted isoxazolidines 50 [26]. It was found that the use of [Cu(MeCN)4]PF6 and Walphos-CFj ligand 51 was essential for obtaining high yield and enantioselectivity (Scheme 2.14). 

Allyltin derivatives have been used for preparation of allyl(dialkoxy)boranes, apparently without concomitant rearrangement of the allyl moiety during reaction. Lithium tetrakis(trimethylsilyl)borate has been prepared, using tri-methylsilyl-lithium as reagent. ... 

The allyltin compounds (CH2 CH CH8)aSn-CaF7-n, (CHa CH-CHj)a-Sn-CaF, and (CHj CH-CHa)aSn(C2F,)j have been synthesized from allyltin bromides and the appropriate perfluoroalkyl-lithium, prepared from the corresponding iodide and methyl-lithium arguments based on comparisons between u.v. and i.r. spectral data for these compounds and those for their alkyl counterparts have been advanced in support of hyperconjugation in allyltin derivatives ... 

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