1. Laboratorium für Organische Chemie, ETH Zürich, CH-8093 Zürich, Switzerland, Departement Technik, Informatik und Naturwissenschaften, Zürcher Hochschule Winterthur, Technikumstrasse 9, CH-8400 Winterthur, Switzerland, The Biodesign Institute and Fulton School of Engineering, Arizona State University, Tempe, Arizona 85287, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907