1. Institute for Organic Chemistry; University of Regensburg; 93053 Regensburg Germany
2. Straubing Center of Science for Renewable Resources; 94315 Straubing Germany
3. Organic Chemistry Department; Universidad Autónoma de Madrid (U.A.M.); 28049 Madrid Spain
4. Inorganic Chemistry Department; Universidad Autónoma de Madrid (U.A.M.); 28049 Madrid Spain