The chemistry of vicinal diamines

Abstract

Compounds incorporating the 1,2-diamine functionality are currently the topic of studies conducted in several fields. For instance, in chemotherapy, various platinum 1,2-diamino complexes are evaluated as antitumor agents that could be employed as substitutes for cisplatin to reduce toxicity and to circumvent drug resistance. Chiral, enantiomerically pure 1,2-diamines (or vicinal diamines) and their derivatives are also used increasingly in stereoselective organic synthesis, for example as chiral auxiliaries, or as metal ligands in catalytic asymmetric synthesis. These utilizations brought about the development of synthetic methods for the preparation of aliphatic 1,2-diamines in diastereomerically and enantiomerically pure form. The problem of stereochemical control encountered in their synthesis depends on the number of substituents on the carbon chain. Thus, it is necessary to control two stereogenic centers when the target compound is disubstituted at the C1 and C2 positions. Numerous strategies have been developed to meet this need. Among relevant methods that have been applied, the diastereoselective introduction of a nitrogen atom in an enantiomerically pure molecule containing another nitrogen atom, and the diastereo- and enantioselective coupling of bisimines, are particularly effective. In the first sections of this account, the occurrence of 1,2-diamines in biologically active compounds-including natural products-and in the field of organic synthesis will be highlighted. In the next section an overview of the methods for preparation of vicinal diamines will be presented.