A Stereospecific Synthesis of Imidazolidin-2-ones from Aziridine-2-carboxylates and Isocyanates
M. S. Kim, Y.-W. Kim, H. S. Hahm, J. W. Jang, W. K. Lee*, H.-J. Ha*
Sogang University, Seoul and Hankuk University of Foreign Studies, Yongin, Korea
21 September 2005 (online)
A mild, Lewis acid (MgBr2 or TMSCl) catalyzed regiospecific and stereospecific reaction of aziridine-2-carboxylates with isocyanates to afford imidazolidin-2-ones is reported. Although aziridine ring expansion reactions are common, stereospecific processes are relatively rare (J.-O. Baeg, C. Bensimon, H. Alper J. Am. Chem. Soc. 1995, 117, 4700-4701). The reaction proceeds with retention of configuration controlled by the α-benzylamine chiral auxiliary in good to excellent yields.