Mechanochemistry has been used for the solvent-free preparation of BH3 for the semiconductor industry. Such ultrahigh-intensity grinding can lead to internal temperatures above 500 °C, and vibratory ball mills were used for the solvent-free preparation of calixarenes.
|Planetary Micro Mill model |
“Pulverisette 7” (classic line)
KF-Al2O3 (5 g, 32 wt % of KF), 4-bromoacetophenone (2, 5 mmol, 1.106 g), phenylboronic acid (1, 6.19 mmol, 0.755 g), Pd(OAc)2 (0.18 mmol, 3.56 mol % 0.04 g) were added to the grinding beaker (volume: 45 mL) together with an adequate number of milling balls and placed inside the Planetary Micro Mill model “Pulverisette 7” (Fritsch GmbH). Another grinding beaker filled with a similar batch was mounted on the opposite position of the rotating disc. The mixtures were subsequently milled with the respective rpm and time. The crude product was immediately extracted with 2 mL of deionized water and 3 mL of ethyl acetate.From their conclusions:
When carrying out the Suzuki-Miyaura reaction with high rpm at adequate reaction times and grinding material one can obtain quantitative yields. The following order of the investigated parameters regarding their positive influence on the formation of 3 [CJ: the Suzuki product] can be derived : rpm > milling time > size of milling balls > number of milling balls > grinding material.So it doesn't appear that there are any examples on kilogram-scale as of yet that I've found -- I'm sure I'll find an example soon enough!
 Anderson, N.G. "Practical Use of Continuous Processing in Developing and Scaling Up Laboratory Processes." Org. Process Res. Dev., 2001, 613–621.
 Schneider, F.; Stolle, A.; Ondruschka, B.; Hopf, H. "The Suzuki−Miyaura Reaction under Mechanochemical Conditions." Org. Process Res. Dev., 2009, 13, 44–48.