Improving the Halogen-Magnesium Exchange by using New Turbo-Grignard Reagents.

This Minireview describes the scope of the halogen-magnesium exchange. It shows that the use of the turbo-Grignard reagent (iPrMgCl⋅LiCl) greatly enhances the rate of the Br- and I-Mg exchange. Furthermore, this magnesium reagent allows the performance of a fast sulfoxide-magnesium exchange. Also, the use of sBuMgOR⋅LiOR (R=2-ethylhexyl) enables a Br-Mg exchange in toluene leading to various Grignard reagents in toluene. Additionally, the new exchange reagent sBu2 Mg⋅2 LiOR (R=2-ethylhexyl) further increases the rate of the halogen-magnesium exchange allowing one to perform a chlorine-magnesium exchange for aromatic chlorides bearing an ortho-methoxy substituent in toluene.