1. Laboratory
of Synthesis and Natural Products, Institute of Chemical Sciences
and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, 1015 Lausanne, Switzerland
2. Department
of Chemistry and Industrial Chemistry, University of Genova, Via Dodecaneso
31, 16146 Genova, Italy