Advances in the chemistry of proline and its derivatives: an excellent amino acid with versatile applications in asymmetric synthesis

Non-proteinogenic prolines have been acknowledged as an important pool for the synthesis of conformationally rigid bioactive peptides, angiotensin converting enzyme inhibitors and as pharmacological probes. Proline and its derivatives are often used as asymmetric catalysts in organic reactions, such as CBS reductions and proline catalyzed aldol reactions, Mannich reactions, and so on. Furthermore l -proline is an osmoprotectant and is therefore frequently used in many pharmacological as well as biotechnological applications. The wide range of chemical and biological applications associated with l -proline has prompted researchers to develop new methodologies for the synthesis of prolines and substituted prolines and to further explore their chemical and biological applications. The present article is an attempt to discuss all the major advances available till date, describing the use of proline in organic asymmetric synthesis, the synthesis of various bioactive molecules or proline as a constituent part of bioactive molecules.