Deliberate generation of imidazolidines from 2-azaallyl anions, and their use as 2-azaallyl anion precursors

Deprotonation of imine 9, which cannot lead to cycloaddition due to the absence of an alkene, resulted in the formation of the imidazolidines 10 and 11 (Scheme 4). Interestingly, the regioselectivity of the dimerization was found to depend on the solvent, providing complementary results. The stereochemistry of these imidazolidines is unknown, although the phenyl groups on 11 were later found to be trans by synthesizing this compound by an unambiguous route.

The imidazolidines 10 and 11 were found to be good precursors of 2-azaallyl anions (Scheme 5). Addition of LDA to a mixture of 10, 11, and trans-stilbene afforded the pyrrolidine 12 as a mixture of three stereoisomers. The imidazolidines used were those formed in the THF reaction in Scheme 4. Thus, definitive evidence for the generation of a 2-azaallyl anion (namely, 13) from imidazolidines has been gathered.



  1. Introduction Observations of imidazolidine intermediates in the deprotonation route to 2-azaallyl anions
  2. Deliberate generation of imidazolidines from 2-azaallyl anions, and their use as 2-azaallyl anion precursors (This page)
  3. Synthesis of Imidazolidines from Diamines, and Their Use in 2-Azaallyl Anion Generation
  4. An Unusual Stereochemical Complementarity
  5. How general is the imidazolidine fragmentation route to 2-azaallyl anions? and Conclusion
  6. Experimental section
  7. References