In this issue's Perspective article, Carmen Nájera and José Sansano (Universidad de Alicante, Spain) discuss the total synthesis of virus inhibitors where 1,3-dipolar cycloadditions, particularly involving azides, nitrones, and azomethine ylides, are the key steps. 



In the paper featured on the outside front cover (above), Kay Severin and colleagues (École Polytechnique Fédérale de Lausanne, Switzerland) report dynamic combinatorial libraries of metal-dye complexes for the sensing of peptide hormones.

Meanwhile, featured on the inside front cover (above) is a Hot article by Subham Mahapatra and Rich Carter (Oregon State University, USA). The researchers have synthesised the western portion of amphidinolides C and F, moving a step closer to the total synthesis of these important natural macrolides.