A mild convenient Barbier-type allylation of aldehydes to homoallylic alcohols via iodide ion promoted stannylation of allylic bromides and chlorides with tin(II) chloride

Article abstract of DOI:10.1055/s-1993-25871

Barbier-type allylation of aldehydes with allylic bromides and tin(II) chloride dihydrate is largely accelerated by adding stoichiometric or substoichiometric amounts of sodium iodide. This method has some merits such as lower temperature, shorter reaction time and/or more choices of solvents for the reaction. Moreover, the activation by the iodide ion enables the use of relatively unreactive allylic chlorides of various structural types (e.g., 3-chloro-2-chloromethylpropene as an isobutene dianion equivalent) and, thus, expands synthetic applicability of this reaction. The major role of the iodide salt is attributed to the in situ generation of the corresponding allylic iodide.