New approaches to C-X bond formation
Universidad de Alcalá, Madrid, Spain
The transformation of C-halogen bonds is a powerful tool to develop new synthesis pathways to give access to new C-C or C-heteroatom bonds. In particular, the synthesis of new fluoroaromatic compounds via C–F bond activation has demonstrated to be important in several applications such as pharmaceuticals, pesticides or advanced organic materials.[1] Furthermore, when directed toward different organic transformations, a large number of C–F bond activations are able to form new C–C bonds; although in the presence of X– species (O–, S–, N–) the formation of C–X bonds may take place.
One of our ongoing research areas is focused on the development of catalytic systems based on cheap and abundant metals such as aluminum, zinc or alkali metals, bearing N- and O- donor ligands.[2] In this context, our studies on a series of alkali metal derivatives with fluorinated Schiff bases, have allowed us to develop a new route to access to benzooxazepines (Figure 1) via a tandem O-H metalation and C-F bond activation process mediated by group 1 metals. Besides, the process takes places at room temperature, this is one of the few cases that this C−F activation is carried out in such mild conditions.[3]

References
[1] J. Wang, M. Sanchez-Rosello, J. L. Acena, C. del Pozo, A. E. Sorochinsky, S. Fustero, V. A. Soloshonok, H. Liu, Chem. Rev. 2014, 114, 2432-2506; S. Purser, P. R. Moore, S. Swallow, V. Gouverneur, Chem. Soc. Rev. 2008, 37, 320-330; R. Berger, G. Resnati, P Metrangolo, E. Weber, J. Hulliger, Chem. Soc. Rev. 2011, 40, 3496-3508
[2] V. Tabernero, M. E. G. Mosquera, T. Cuenca, Organometallics, 2010, 29, 3642. M.T. Muñoz, C. Urbaneja, T. Cuenca, M.E G. Mosquera, Chem. Commun, 2011, 47, 11757; F. M. García-Valle, V. Tabernero, T. Cuenca, M. E. G. Mosquera, J. Cano, S. Milione, Organometallics, 2018, 37, 837-840; M. T. Muñoz, M. Palenzuela, T. Cuenca, M. E. G. Mosquera, ChemCatChem, 2018, 10, 936; D. Sanchez-Roa, T. G. Santiago, M. Fernandez-Millan, T. Cuenca, P. Palma, J. Campora, Marta E. G. Mosquera. Chem Commun., 2018, 54, 12586-12589.
[3]. F. G. García-Valle, V. Tabernero, T. Cuenca, J. Cano, M.E.G. Mosquera, Organometallics, 2019, 38, 894−904.