Encapsulation of a cationic carbodiimide condensing agent within a self-assembled hexameric capsule made of resorcin[4]arene units provides a nano-environment that efficiently steers the substrate selectivity in the amide synthesis reaction between carboxylic acids and primary amines. While in solution pairs of acids react similarly with a given amine, in the presence of the capsule the formation of the shorter amide is greatly favored.

A complete protocol for the synthesis of new palladacyclopentadienyl complexes with purine-based carbenes as supporting ligands is described. The new organometallic compounds were exhaustively characterized using NMR and infrared spectroscopies and elemental analysis. The single-crystal X-ray structure of complex 2b coordinating also a triphenylphosphine was resolved. Some of these complexes showed an antiproliferative activity comparable to or better than that of cisplatin on two human ovarian cancer lines: A2780 (cisplatin-sensitive) and A2780cis (cisplatin-resistant). Moreover, for complexes 2 and 3 (coordinating one purine-based N-heterocyclic carbene ligand and one phosphine) the cytotoxicity is associated with an evident induction of apoptosis. Finally, complexes 3, bearing one purine-based N-heterocyclic carbene ligand and one 1,3,5-triaza-7-phosphaadamantane, proved practically inactive on non-tumour fibroblast cells (MRC-5).KEYWORDS antiproliferative and pro-apoptotic activity, N-heterocyclic carbenes, ovarian cancer, palladacyclopentadienyl complexes, purine bases

The synthesis of substituted 1H-tetrazoles from aliphatic or aromatic isonitriles and trimethylsilyl azide can be efficiently promoted by the hexameric capsule of resorcin[4]arene as a supramolecular self-assembled catalyst. The reaction is sensitive to the size and nature of the substrate and is driven by encapsulation of the reagents within the cavity of the supramolecular catalyst.

Supramolecular Catalysis in the Synthesis of Substituted 1H-Tetrazoles from Isonitriles by a Self-Assembled Hexameric Capsule. -The synthesis of substituted 1H-tetrazoles from aliphatic or aromatic isonitriles and trimethylsilyl azide can be efficiently promoted by the hexameric capsule of resorcin[4]arene as a supramolecular self-assembled catalyst. The reaction is sensitive to the size and nature of the substrate and is driven by encapsulation of the reagents within the cavity of the supramolecular catalyst. -(GIUST, S.; LA SORELLA, G.; SPERNI, L.; FABRIS, F.; STRUKUL, G.; SCARSO*, A.; Asian J. Org. Chem. 4 (2015) 3, 217-220, http://dx.doi.org/10.1002/ajoc.201402229 ; Dip. Sci. Mol. Nanosist., Univ. Ca' Foscari, I-30123 Venezia, Italy; Eng.) -Nuesgen 29-191