Grignard reagents are generally obtained by mixing organic halides and magnesium pieces in a high-purity organic solvent.While this method has been widely used for about 120 years, it requires complicated experimental operations such as the need to strictly control the temperature, a large amount of waste derived from organic solvents, and the cost of the solvent. Problems such as concern about toxicity and toxicity are mentioned.

　Since there was a need to develop a method for easily synthesizing Grignard reagents without using harmful organic solvents as much as possible, in this study, we attempted to use mechanochemical synthesis using a crusher called a ball mill. ..In this method, a metal ball is placed in a jar together with a reaction substrate, vibrated quickly from side to side, and mechanically strongly agitated, whereby high reaction efficiency can be realized without using a solvent.

　In fact, by this method, we succeeded in synthesizing a Grignard reagent by adding a very small amount of an organic solvent to an organic halide and a magnesium piece.Since it is a synthetic method that is not easily affected by the moisture and oxygen in the container, the amount of organic solvent used can be reduced to about one-tenth of the usual amount, and there is no need to use expensive high-purity organic solvents.Since it is pulverized by a ball mill, a paste-like Grignard reagent is prepared and can be used as it is for various solvent-free organic reactions.

　The preparation method developed in this research has succeeded in greatly simplifying the experimental operation and drastically reducing the amount of solvent used, thereby expanding the production process and reducing the cost of chemical products, pharmaceuticals, functional materials, etc. with reduced environmental load. It is expected to contribute to.

Paper information:[Nature Communications] Mechanochemical Synthesis of Magnesium-based Carbon Nucleophiles in Air and Their Use in Organic Synthesis