An Easy Stereo-Specific and Regio-Selective Reaction for the Synthesis of Ester-[70]-Fullerene Derivatives

Abstract

Medicinal chemistry is one of the many fields where fullerene derivatives have been shown to be active and useful.[1,2] Wudl and coworkers reported the interactions of [60]-fullerene derivatives with the active site of HIV protease, driven by the lipophilicity of the carbon cage.[3] Unfortunately, fullerene derivative applications in this field are hindered mainly by their low water-solubility. To date, water-soluble fullerene C70 derivatives have not been extensively investigated. The lack of low symmetry of the C70 cage makes its selective functionalization more challenging than for C60. Therefore, just a few C70 water-soluble derivatives have been reported. [4,5] Here we report an efficient stereo-specific and regio-selective reaction for the synthesis of ester-pyrrolidinofullerene derivatives. These compounds are good precursors for the synthesis of their corresponding water-soluble carboxylic acid-pyrrolidinofullerenes. Figure 1. Stereo-specific and regio-selective 1,3-dipolar cyclo-addition reaction of ester-[70]-fullerene derivatives. A. Jensen, S. Wilson, D. Schuster, Bioorg. Med. Chem. 1996, 4, 767.T. Da Ros, M. Prato, Chem. Commun. 1999, 663.S. Friedman, D. DeCamp, R. Sijbesma, G. Srdanov, F. Wudl, G. Kenyon, J. Am. Chem. Soc. 1993, 115, 6506-6509.P. Witte, F. Beuerle, U. Hartnagel, R. Lebovitz, A. Savouchkina, S. Sali, D. Guldi, N. Chronakisd, A. Hirsch, Org. Biomol. Chem. 2007, 5, 3599.A. Kornev, A. Peregudov, V. Martynenko, J. Balzarini, B. Hoorelbekec, P. Troshin, Chem. Commun. 2011, 47, 8298–8300. Figure 1