Ring closure to β-turn mimics via copper-catalyzed azide/alkyne cycloadditions

Copper-catalyzed azide alkyne cycloadditions of the linear substrates 1 were used to form the cyclic derivatives 2. Computational, NMR, and CD analyses of these compounds indicate that their most favorable conformational states include type I and type H beta-turn conformations. Selectivity for the dimeric products 6 in these cyclization reactions is discussed.