Synthesis of Functionalized Proline-Derived Azabicycloalkane Amino Acids and Their Applications in Drug Discovery: Recent Advances

After the first synthesis reported in 1994, azabicycloalkane amino acids have raised increasing interest, becoming one of the most important classes of constrained dipeptide mimics. Their incorporation into peptidomimetic structures allowed the obtainment of a wide range of biologically active compounds. Over the years, different research groups have worked at the development of synthetic strategies to gain these rigid dipeptide surrogates, nevertheless, methods affording functionalized and “easy-to-functionalize” derivatives are quite less described. The presence of a derivatizable azabicycloalkanone core could allow the introduction of chemical modifications aimed to improve the pharmaceutical properties of a biologically active compound without the need for redesigning its chemical synthesis. This account has collected and critically surveyed relevant approaches to the synthesis of functionalized azabicycloalkane amino acids, focusing the attention on the period of 2010 to the present. Moreover, recent applications of these compounds in drug discovery will be discussed.