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in activation strain (DDEz = 16.3 kJ/mol), in line with
str
the aforementioned structural differences in transition state
geometries.
In conclusion, the stereospecific ring opening of
2-substituted N,N-dibenzylaziridinium ions by hydride at the
unsubstituted aziridine carbon atom towards the corres-
ponding 2-aminopropanes has been described for the first time
and stands in contrast with the previously reported ring
opening of the same aziridinium salts by bromide at the
substituted position. The observed regioselectivity was ratio-
nalized by means of DFT calculations. Future theoretical
work will focus on analyzing the main factors causing the
difference in regioselectivity for bromide and hydride attack
on the aziridinium rings, as well as elucidating the mechanism for
the formation of the N-allyl-N-benzyl-N-(1-phenylethyl)amine
upon reaction with LiAlH4.
The authors are indebted to the Korea Science and
Engineering Foundation (R01-2007-000-20037-0), the Center
for Bioactive Molecular Hybrides (KRF-2008-313-C00481),
the ‘‘Fund for Scientific Research-Flanders (Belgium)’’
(FWO-Vlaanderen), Belspro (IAP-PAI program) and Ghent
University (GOA) for financial support.
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Notes and references
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2510 | Chem. Commun., 2009, 2508–2510