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Nucleophilic Ring‐Opening of Azetidinium Ions: Insights into Regioselectivity
Author(s) -
Couty François,
David Olivier,
Durrat François,
Evano Gwilherm,
Lakhdar Sami,
Marrot Jérome,
VargasSanchez Monica
Publication year - 2006
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200600200
Subject(s) - regioselectivity , chemistry , enantiopure drug , nucleophile , substituent , trifluoromethanesulfonate , azide , azetidine , ring (chemistry) , benzylamine , medicinal chemistry , stereochemistry , organic chemistry , enantioselective synthesis , catalysis
Enantiopure azetidinium salts presenting various and representative substitution patterns at C‐2, C‐3 and C‐4 have been prepared by alkylation of the corresponding azetidine with methyl trifluoromethanesulfonate. These compounds were treated with an array of nitrogen (azide anion or benzylamine) and oxygen (acetate anion or alkoxides) nucleophiles which provided interesting insights into the regioselectivity of the ring‐opening process. Nucleophilic opening occurred in most cases regioselectively at C‐4 with azetidinium ions possessing no substituent at this position. On the other hand, highly regioselective opening at C‐2 occurred with trisubstituted azetidinium ions bearing a methyl group at C‐4. Experimental selectivities together with DFT calculations have allowed a better understanding of the parameters governing the regioselectivities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)