1. Department of Organic Chemistry, Prague Institute of Chemical Technology, Technicka 6, 166 28 Prague 6, Czech Republic, Institute of Organic Chemistry and Biochemistry, v.v.i. Academy of Sciences of the Czech Republic, Flemingovo 2, 166 10 Prague 6, Czech Republic, Institute of Chemical Process Fundamentals, v.v.i. Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic, and Department of Inorganic Chemistry, Charles University, Hlavova 8, 128 43 Prague 2, Czech Republic