Comprehensive study of the organic-solvent-free CDI-mediated acylation of various nucleophiles by mechanochemistry.

Acylation reactions are ubiquitous in the synthesis of natural products and biologically active compounds. Unfortunately, these reactions often require the use of large quantities of volatile and/or toxic solvents, either for the reaction, purification or isolation of the products. Herein we describe and discuss the possibility of completely eliminating the use of organic solvents for the synthesis, purification and isolation of products resulting from the acylation of amines and other nucleophiles.

Mechanosynthesis of amides in the total absence of organic solvent from reaction to product recovery.

The synthesis of various amides has been realised avoiding the use of any organic solvent from activation of carboxylic acids with CDI to isolation of the amides. Mechanochemistry was the key point of the process allowing rapid formation of the amide bond and efficient water-based purification of the final products.

Iron(II) triflate as a catalyst for the synthesis of indoles by intramolecular C-H amination.

A practical iron-catalyzed intramolecular C-H amination reaction and its application in the synthesis of indole derivatives are presented. As a catalyst, commercially available iron(II) triflate is used.

Iron salts in the catalyzed synthesis of 5-substituted 1H-tetrazoles.

Clicking iron: Cheap and environmentally friendly [Fe(OAc)(2)] is used for the catalysis of cycloadditions between aryl nitriles and trimethylsilyl azide to prepare substituted 1H-tetrazoles in good yield (see scheme).

Iron-catalyzed intramolecular o-arylation: synthesis of 2-aryl benzoxazoles.

A practical iron-catalyzed intramolecular O-arylation reaction and its application in the synthesis of benzoxazole derivatives, starting from the readily available 2-haloanilines, is presented. The key cyclization step involves the use of a combination of the cheap and environmentally friendly FeCl(3) and 2,2,6,6-tetramethyl-3,5 heptanedione (TMHD) as the catalyst system.