Synthesis of core‐functionalised naphthalene diimides from naphthalenetetracarboxylic dianhydride using a vibratory ball mill: bromination, imidization and Heck‐type reactions.

<p>The synthesis of 9 core‐functionalised naphthalene diimide (c‐NDI) residues is reported via a 3‐step solvent free synthesis from naphthalenetetracarboxylic dianhydride using only mechanochemical activation. Selective dibromination and subsequent dimidiation were achieved for the first time in a vibratory ball mill, resulting in the key structural intermediate, 2,6‐dibromonaphthalenediimide (DBND), which is the basis for elaboration into a multitude of organic electronic materials. Our new synthesis of DBND is achieved in just 5 hours’ reaction time over two steps compared to typical solution state times of 24 hours. Subsequent Heck‐type cross coupling reactions, with a range of styrene residues, produced a series of c‐NDIs in good yields. The Heck‐type reactions are rapid (1.5 hours), require no additional heating or solvent and are tolerant of atmospheric moisture and air.</p>