Powerful New Umpolung C-C and C-N Bond Forming Reactions via Enolonium Species

Enolonium Species derived from carbonyl compounds and hypervalent iodine reagents have been hypothesized as highly reactive intermediates in important reactions such as α-halogenation, -trifluoromethylation, -oxygenation and numerous other oxidative processes.¹ Meanwhile the actual structure, enolate-like (4) or ketone-like (3), has remained controversial since first proposed over 30 years ago. We recently reported the first characterization of these elusive species and showed them to have enolate like structure 4.²

We will briefly discuss how this mechanistic analysis and insight allowed us to design and develop a series of novel C-C and C-N bond forming reactions that rely on the unique and powerful electrophilic reactivity of enolonium species (Scheme 1).^2,3,4,5,6

References:

1. V. V. Zhdankin, “Hypervalent Iodine Chemistry: Preparation, Structure, and Synthetic Applications of Polyvalent Iodine Compounds”, Wiley, 2013
2. S. Arava, J. N. Kumar, S. Maksymenko, M. A. Iron, K. N. Parida, P. Fristrup, A. M. Szpilman* Angewandte Chemie Int. Ed., 2017, 56, 2599-2603.
3. O. S. Shneider, E. Piseravsky, P. Fristrup, A. M. Szpilman* Organic Letters, 2015, 17, 282-285
4. T. A. Targel, J. N. Kumar, O. S. Shneider, S. Bar, N. Fridman, S. Maximenko, A. M. Szpilman* Organic & Biomolecular Chemistry, 2015, 13, 2546-2549
5. S. Maksymenko, K. N. Parida, G. Pathe, A. More, Y. Lipisa, A. M. Szpilman*, Organic Letters 2017, In ASAPs
6. A. More, G. Pathe, K. N. Parida, S. Maksymenko, Y. Lipisa, A. M. Szpilman*, Submitted for Publication 2017