Solvent-Free Asymmetric Alcoxy-Selenylation of Styrenes using I₂ / DMSO Catalytic System

The addition of electrophilic selenium species to alkenes with the formation of a seleniranium intermediate, that reacts with nucleophiles, is one of the most useful method for the formation of new carbon-selenium bonds.¹ Several reagents have been used with the purpose of prepare or generate the electrophilic selenium species, highlighting the catalytic system I₂/DMSO under solvent-free conditions.² This system was successfully employed for the alcoxy-chalcogenylation of alkenes using non-chiral diselenides.³ Herein, we reported a study about the employment of this system in the asymmetric alcoxi-selenyation of styrenes by using chiral non-racemic diselenides and chiral non-racemic alcohols and how it influences on the diastereoisomeric excesses of the products. The desired products were obtained in satisfactory yields and diastereoisomeric excesses under microwave irradiation or conventional heating. The methodology allowed, for example, the preparation of natural products derivatives such as when camphor and menthol were used as alcohols.

References

¹ Tiecco, M.; Testaferri, L.; Santi, C.; Marini, F.; Bagnoli, L.; Temperini, A. a Tomassini, C. Eur. J. Org. Chem. 1998, 2275.

2 Azeredo, J. B.; Godoi, M.; Martins, G. M.; Silveira, C. C. and Braga, A. L. J. Org. Chem., 2014, 79, 4126.

³ Vieira, A. A.; Azeredo, J. B.; Godoi, M.; Santi, C.; da Silva Junior, E. N. and Braga A. L. et. al. J. Org. Chem., 2015, 80, 2120.