Formation of Grignard Reagents from Alkyl Halides
Description: Treatment of alkyl halides with magnesium metal leads to formation of a Grignard reagent.
Notes: X here is a halide. This reaction works with alkyl chlorides, bromides, or iodides. Sometimes “ether” is also written. This is the solvent, it doesn’t actually participate in the reaction.
Notes: Note that in example 2 the structure below the reaction is diethyl ether. This is just a solvent, it doesn’t take part in the reaction.
Mechanism: Note that the mechanism of this reaction is generally not considered important for Org 1/ Org 2.
The first step here is donation of an electron to Br from the Mg. This leads to fragmentation of the C–Br bond, forming a radical. The second step is reformation of the C–Mg bond to give the Grignard reagent.