The formation of chiral C-C and C-X bonds is the most fundamental process in the synthesis of complex molecules from simple ones. In most asymmetric transformations involving olefins as prochiral reagents (i.e. epoxidation, hydrogenation, etc.), 1,1-disubstituted olefins are systematically challenging substrates.[1] This is mainly because the chiral transition metal catalyst has difficulty in controlling not only the specific attackt at the desired terminal position rather than at the more substituted α-position, but also the face selectivity coordination (due to the presence of the two relatively similar substituents at the geminal position). We recently showed that the highest reported enantioselectivities in the Ir-catalyzed hydrogenation of a very large range of simple 1,1-disubstituted olefins can be achieved by introducing a biaryl phosphite moiety into the ligand.[2] In this communication, I will present our latter results in the asymmetric hydroboration and hydroformylation of this elusive substrate class. [1] See for example: a) Wang, B.; Wong, O. A.; Zhao, M.-X.; Shi, Y. J. Org. Chem. 2008, 73, 9539 (epoxidation); b) Wang, X.; Zak, M.; Maddess, M.; O'Shea, P.; Tillyer, R.; Grabowski, E. J. J.; Reider, P. J. Tetrahedron Lett. 2000, 41, 4865 (dihydroxylation). [2] See for instance: Mazuela, J.; Verendel, J. J.; Coll, M.; Schäffner, B.; Börner, A.; Andersson, P. G.; Pàmies, O.; Diéguez, M. J. Am. Chem. Soc. 2009, 131, 12344.

Asymmetric transformations using 1,1-disubstituted olefins as challenging substrates

251st National Meeting (2016)

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