Asymmetric Synthesis of Chiral Polynitroazetidine Derivatives
Polynitroazetidine derivatives, such as 3,3-dinitroazetidine (DNAZ), 1,3,3-trinitroazetidine (TNAZ), N-2',4'-dinitrophenyl-3,3-dinitroazetidine (DNPDNAZ) and 1-nitroso-3,3-dinitroazetidine (nitroso-DNAZ), are important materials having high energies resulting from the highly strained azetidine ring and the nitro groups. In addition, 1-bromoacetyl-3,3-dinitroazetidine (ABDNAZ) as one of the energetic nitroazetidine derivatives has recently been developed as anticancer agent and radiation sensitizer in pharmaceutical research field. Owing to these importances, considerable effort has been devoted to the development of a variety of nitroazetidine derivatives. In particular, the synthesis of 2-substituted-1,3,3-trinitroazetidine derivatives has never been reported despite their versatile applicability in the fields of both drug discovery and energetic materials. Notably, since the chiral 2-substituted-1,3,3-trinitroazetidines were first synthesized in our laboratory, further studies have developed new synthetic routes for generating various chiral 2-substituted polynitroazetidines.
Here, I present the asymmetric synthesis of 2-nitratoethyl-TNAZ, 2-nitratoethyl-3-methylnitrato-1,3-dinitroazetidine (2-nitratoethyl-NMDNAZ) and dimeric-TNAZ as the chiral 2-substituted polynitroazetidines.