Azides DOI: 10.1002/anie.200400657 Organic Azides: An Exploding Diversity of a Unique Class of Compounds Stefan Bräse,* Carmen Gil, Kerstin Knepper, and Viktor Zimmermann Angewandte Chemie Keywords: cycloadditions · heterocycles · nitrenes · rearrangements · Staudinger reaction Dedicated to Professor Rolf Huisgen S. Bräse et al. Reviews 5188 www.angewandte.org  2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Angew. Chem. Int. Ed. 2005, 44, 5188 – 5240