Hydromagnesiation of 1,3-Enynes by Magnesium Hydride for Synthesis of Tri- and Tetra-substituted Allenes

摘要

A protocol for regio-controlled hydromagnesiation of 1,3-enynes was developed using magnesium hydride that is generated in situ by solvothermal treatment of sodium hydride (NaH) and magnesium iodide (MgI2) in THF. The resulting allenylmagnesium species could be converted into tri- and tetra-substituted allenes by subsequent treatment with various carbon- and silicon-based electrophiles with the aid of CuCN as a catalyst.