G. Berger et al. / Tetrahedron Letters 54 (2013) 545–548
547
tion, an unexpected loss of regioselectivity upon nosyl activation
was demonstrated, when it is largely accepted that benzyl aziridi-
niums are preferentially opened at the aryl substituted carbon.
anti-Configured diamines were produced from their amino alcohol
precursor with an overall yield of 41 to 57%. Yield is significantly
decreased (15–33%) for the syn isomers as more steps were
needed. No separation of regioisomers nor diastereomers were
needed to produce enantiopure anti-diamines. Nevertheless, pro-
duction of syn isomers was a little trickier. Firstly, as the chlorina-
tion steps did not proceed through a stereospecific mechanism
(but with good stereoselectivity), either the aminochloride 7 or
the aziridine 8 had to be purified and secondly, regioisomers
resulting from the opening of nosylaziridines 9 had to be separated
through flash chromatography.
The use of chiral aziridines as synthetic intermediates again
supports the importance of this three-membered ring in modern
organic chemistry.
Supplementary data
Scheme 3. Conversion of 5 to 15N-labeled anti-b-diamines
Supplementary data associated with this article can be found,
anti series were synthesized to compare their physico-chemical
properties with those of their diastereomeric most active analogs.
Finally, the 15N-enriched vicinal diamines were transformed
into their platinum-based anticancer analogs by reaction with
K2PtCl4 in water, the pH being kept constant over the course of
the reaction (Scheme 4).
References and notes
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Scheme 4. Example of production of platinum-based anticancer compounds from
vicinal diamines.