1. For a general review on chromium oxidations see e.g. G. Cainelli and G. Cardillo Chromium Oxidants in Organic Chemistry (Springer Berlin 1984); S. V. Ley and A. Madin in Comprehensive Organic Synthesis B. M. Trost I. Fleming S. V. Ley Eds. (Pergamon Oxford 1991) vol. 7 pp. 251–289.
2. For example for a green route from cyclohexene to adipic acid see
3. Sato K., Aoki M., Noyori R., Science 281, 1646 (1998).
4. For a general discussion of atom economy in organic synthesis see
5. The Atom Economy—A Search for Synthetic Efficiency