Additions of Allylic Halostannanes to Aldehydes

Allyl iodide undergoes an oxidative metalation upon treatment with Snp2 in 1,3-dimethyl-2-imidazolidinone (DMI) [44]. The resulting allyl iododifluorotin species adds to aldehydes to afford homoallylic alcohols (Table 28) The reaction can also be performed with SnCh or SnBr2. 

In a similar vein, allylic iodides and, to a lesser extent, bromides undergo Barbier addition to aldehydes in the presence of activated tin powder in THF (Table 29) [45]. The reaction is thought to involve a diallyltin dihalide intermediate. Similar results were obtained when diallyltin dibromide, prepared independently, was used for the addition. 

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