trans-Cyclopentane-1,2-diamine: the second youth of the forgotten diamine

Abstract

Despite its early description, trans-cyclopentane-1,2-diamine has been underestimated historically. Its non-commercial availability, extreme instability and complexity of the classical reported syntheses have produced far less interest amongst chemists than its higher homologue trans-cyclohexane-1,2-diamine, perhaps the most widely used diamine for the synthesis of ligands and receptors. However, the recent development of novel and efficient synthetic approaches has stimulated renewed interest in this chiral motif for a broad range of applications. In the first part of this tutorial review we shall discuss the existing methods for the preparation of trans-cyclopentane-1,2-diamine and some of its derivatives, in both racemic and enantioenriched forms. In subsequent sections, recent findings employing this diamine as a scaffold for chiral ligands, receptors and biologically active compounds will be highlighted.