Nucleophilic Opening of Aziridines

The ring-opening reactions of aziridines 16 with amines deserve special attention. Unlike ring-openings with the other nucleophiles examined, they do not require added base, and they do not produce stoichiometric byproducts (as with azide). In certain cases, they do not even require a solvent, as exemplified by the ring-opening of aziridine 18 (Table 12.12, entries 1-3). In addition, the reactions 

Entry Amine Regioselectivity (19 20) reaction method1 1 Product, yield (mp)[b  

Of the 135 possible ring-opened products, 102 crystallized and were collected by 

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The nucleophilic opening of aziridines has also proved useful in peptide synthesis. A number of A-tosyl-aziridines (253 R = H, Me, Pr, or Ph) were opened with phenol or phenate ion in an attempt to introduce the /8-phenoxy-group to amino-acids, such groupings being known to be present in cyclopeptide alkaloids. In the case of (253 R = Ph) the ring was regioselectively cleaved to (254) (100%). 

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