Activation of Lithium Metal

Variations in the properties of the surface of metallic lithium are limited to the particle size of Li-sand, prepared by vigorously stirring molten lithium in an inert solvent, followed by cooling. Particle sizes varying from 25 /i to 150 were used in the above-mentioned studies on the optical purity of organolithium compounds [50a, 50b]. 

One very important recent development in the use of lithium in Barbier-type reactions has drawn great attention though, i.e. the application of ultrasound. 

Sonication, The introduction of sonication (for a recent review on sonication see [31]) in Li-Barbier chemistry [32] has enhanced the synthetic importance of this procedure  

Wet technical grade solvent could be used at room-temperature, and 

direct in situ formation of benzylic, allylic and vinylic organolithium compounds were also possible leading to ketone-addition products in good yields. 

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