1. Department of Chemistry, Center for Chemical Methodology and Library Development, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
2. Université Paris‐Sud 11, Laboratoire de Synthèse Organique & Méthodologie, ICMMO (CNRS UMR 8182), 15 rue Georges Clemenceau, 91405 Orsay cedex, France, Fax: +33‐1‐69156278