1. For instance, see: (a) Heinze, K. Chem. Eur. J. 2001, 7, 2922;
2. (b) Gershuns, A. L.; Rastrepina, I. A. Akad. Nauk SSSR 1969, 17, 242;
3. (c) Unicler, S. R. French Patent FR 2431489, 1981;
4. (d) Atkins, K. J.; Honeybourne, C. L. Spec. Publ.–R. Soc. Chem. 1991, 91, 121.