We herein report that magnesium hydride, generated via solvothermal treatment of magnesium iodide with sodium hydride in tetrahydrofuran, is capable of promoting the hydromagnesiation of 1-arylallenes. The resulting cinnamylmagnesium species could be functionalized by the subsequent treatment with aldehydes or ketones in the presence of zinc chloride to form various homoallylic alcohols in a diastereoselective manner via a 6-membered ring chair-like transition state.
Ng et al. (Fri,) studied this question.