During the last decade numerous protocols have been published using the method of ball milling for synthesis all over the field of organic chemistry. However, compared to other methods leaving their marks on the road to sustainable synthesis (e.g. microwave, ultrasound, ionic liquids) chemistry in ball mills is rather underrepresented in the knowledge of organic chemists. Especially, in the last three years the interest in this technique raised continuously, culminating in several high-quality synthetic procedures covering the whole range of organic synthesis. Thus, the present tutorial review will be focused on the highlights using this method of energy transfer and energy dissipation. The central aim is to motivate researchers to take notice of ball mills as chemical reactors, implementing this technique in everyday laboratory use and thus, pave the ground for future activities in this interdisciplinary field of research.

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The ultrasound-assisted cross-linking of chitosan with hexamethylene diisocyanate with the simultaneous incorporation of Pd(OAc)2 resulted in a catalyst which is suitable for the solid-state Suzuki cross-coupling of poorly reactive (hetero)aryl chlorides with phenylboronic acid. Reactions were carried out solvent-free in planetary ball mill allowing the catalyst to be recycled several times.

The deacetylation of chitin was studied as a function of NaOH concentration, reaction time and temperature as determined by acid-base titration. Deacetylation was performed by classical heating or under microwave irradiation. Microwave experiments were carried out to compare the results with selected examples from the Chinese literature. The maximum degree of deacetylation (88 %) was obtained after 30 min of classical heating (135°C) in 50 wt % NaOH solution.