Ring-Opening and -Expansion of 2,2′-Biaziridine: Access to Diverse Enantiopure Linear and Bicyclic Vicinal Diamines

The
chiral pool-derived 1,1′-ditosyl-2,2′-biaziridine
has been established as a valuable building block for the divergent
synthesis of enantiopure vicinal diamines. Efficient procedures for
the regioselective ring opening of the biaziridine with oxygen, sulfur,
nitrogen, and carbon nucleophiles are described. The strategic use
of nucleophiles bearing pendant functionality allows further elaboration
of the acyclic products to a variety of 2,2′-bicyclic-embedded
diamines. Desymmetrization of the biaziridine has also been accomplished
via the selective monoaddition of organocuprates.