1. Department of Chemistry and Bioscience; Aalborg University; Frederik Bajers Vej 7H 9220 Aalborg Ø Denmark
2. Institute of Organic Chemistry; Johannes Kepler University Linz; Altenbergerstr 69 4040 Linz Austria
3. Faculty of Science; University of South Bohemia; Branišovská 31 37005 České Budějovice Czech Republic