De Kimpe aziridine synthesis explained

The De Kimpe aziridine synthesis is a name reaction of organic chemistry, for the generation of aziridines by the reaction of α-chloroimines with nucleophiles such as hydride,^[1] cyanide, or Grignard reagents.^{[2] [3]}

The De Kimpe aziridine synthesis is suitable for both aldimines and ketimines, particularly those with two alkyl substituents on the α-carbon (Thorpe-Ingold effect).^[4]

Mechanism

The nucleophile attacks the imino carbon atom, forming a tetrahedral intermediate. The intermediate then undergoes an intramolecular nucleophilic substitution, with the negatively charged nitrogen atom attacking the α-carbon and having the chloride anion as the leaving group.

Notes and References

1. De Kimpe. Norbert . Moens. Luc. 6 February 1990. Synthesis of 1,2,3-trisubstituted and 1,2,2,3-tetrasubstituted aziridines from α-chloroketimines. Tetrahedron. 46. 8. 2965–2974. 10.1016/S0040-4020(01)88388-5.
2. De Kimpe. Norbert. 31 March 2007. Asymmetric Synthesis of Aziridines by Reduction of N-tert-Butanesulfinyl α-Chloro Imines. The Journal of Organic Chemistry. 72. 9. 3211–3217. 10.1021/jo0624795. 17397222.
3. Denolf. Bram. Mangelinckx. Sven. Törnroos. Karl W.. Norbert. De Kimpe. 14 June 2006. Use of α-Chlorinated N-(tert-Butanesulfinyl)imines in the Synthesis of Chiral Aziridines. Organic Letters. 8. 14. 3129–3132. 10.1021/ol0611245. 16805569.
4. de Kimpe. Norbert. Verhé. Roland. de Buyck. Laurent. Schamp. Niceas. 1 January 1977. Reaction of secondary N‐1‐(2‐chloroalkylidene)amines with lithium tetrahydridoaluminate: Synthesis and rearrangement of 1,2,2‐trisubstituted aziridines. Recueil des Travaux Chimiques des Pays-Bas. 96. 9. 242–246.