Surface of Metallic Magnesium

It seems obvious that a smooth Barbier reaction is promoted by a clean metal surface mention has been made (vide supra) of the advantage of shiny, freshly sublimed magnesium crystals. In Sect. 4.2 a discussion was presented of reports, in the beginning of the 1970s, on Grignard reagent formation reactions at low 

A supremely clean and active metal surface seems to be formed during the cutting of chips from a rod of metallic magnesium at the point of a cutting tool, as reported in a patent as early as 1945 [18]. 

The apparatus described facilitates a Grignard type reaction by continually cutting chips from the metal in the presence of an appropriate solvent together with the organohalide which reacts on the clean nascent chip surface. 

Continued research [19] in this field, which was named mechanical activation , demonstrated its advantages. The Grignard reaction starts extremely smoothly and 

The usual precautions required to maintain the apparatus and reagents absolutely anhydrous are unnecessary when the more easily prepared Grignard reagents are produced by this procedure. 

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