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In the last few years click chemistry reactions, and in particular copper-catalyzed cycloadditions, have been used intensively for the preparation of new bioconjugate molecules and materials applicable to biomedical and pharmaceutical areas. This review will be focused on conjugates of the tripeptide Arg-Gly-Asp formed by means of click chemistry reactions. This sequence is a well known binding motif for specific transmembrane proteins and is involved in cellular adhesion to the extracellular matrix, allowing the selective recognition of the biomolecule or polymer in which it is incorporated.

A practical synthetic scheme was developed to prepare both the cis- and trans-fused stereoisomers of N-Boc- l -octahydroindole-2-carboxylic acid ( l -Oic) methyl ester. Key event of the synthetic sequence was the ring-closing metathesis of a suitable diallylated proline derivative. This is the first reported practical synthesis of the trans-fused isomer. Functionalization of the octahydroindole nucleus by electrochemical oxidation followed by acid-catalysed allylation paved the way for the preparation of reverse-turn dipeptide mimics.

An advantageous ligand-free protocol for Suzuki couplings is described. The synthetic procedure entails microwave irradiation for the reduction of the reaction times and the use of silica cartridges for the purification. Dihalo-pyrimidine structures, interesting scaffolds in medicinal chemistry, were chosen as test compounds.

A practical approach to the synthesis of a conformationally constrained spiroazabicycloalkane aminoacid scaffold as a reverse-turn inducer dipeptide mimic is described.