Synthesis, Configuration, and 15N NMR Spectra of Iminoaziridines. Synthons Equivalent to Three Components of the Ugi Reaction

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• 作者：Helmut Quast ; Sven Aldenkortt ; Bernd Freudenreich ; Peter Schä ; fer ; Manfred Hagedorn ; Jens Lehmann ; Klaus Banert
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：March 2, 2007
• 年：2007
• 卷：72
• 期：5
• 页码：1659 - 1666
• 全文大小：144K
• 年卷期：v.72,no.5(March 2, 2007)
• ISSN：1520-6904

文摘

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Monocyclic iminoaziridines and exo-endo diastereomers of spirocyclic iminoaziridines that are derivedfrom norbornane are prepared in batches of up to 10 g to foster applications as building blocks in syntheses.N,N'-Disubstituted ges/gifchars/alpha.gif" BORDER=0>-haloamidines, which are readily available in two steps from N-substitutedges/gifchars/alpha.gif" BORDER=0>-halocarboxamides, are 1,3-dehydrohalogenated by strong bases such as alkali-metal hydrides or tert-butoxides to afford distillable oils or low-melting solids, which consist of slowly interconverting E-Zdiastereomers of the title compounds. The scope and limitations are outlined for this reaction. Theconfigurations E and Z that were assigned on the basis of homoallylic ¹H-¹H coupling and asymmetricsolvent-induced shifts required that, in ¹³C NMR spectra, the observed ges/gifchars/gamma.gif" BORDER=0 >-effects of substitutents at theimino nitrogens were deshielding, contrary to the well-known shielding ges/gifchars/gamma.gif" BORDER=0 >-effects in all other types ofC=N compounds. However, an NOE NMR study demonstrated unequivocally that the previousassignments are correct and hence the observed ges/gifchars/gamma.gif" BORDER=0 >-effects actually deshielding. The ranges of ¹⁵N NMRchemical shifts span more than 60 ppm. Neither the ges/gifchars/beta2.gif" BORDER=0 ALIGN="middle">- nor the ges/gifchars/gamma.gif" BORDER=0 >-effects of substituents on both types ofnitrogen follow a uniform increment pattern.