This volume in the venerable Organic Reactions series contains three chapters focusing on the introduction or the removal of nitrogen from organic compounds. The first chapter features a classic chemical reaction for introducing nitrogen into organic compounds, namely the Schmidt Reaction. The second chapter highlights a less-well-known yet fascinating transformation that introduces nitrogen into organic compounds, The Neber Rearrangement. The third chapter describes an unusual class of reactions that involve the loss of small molecular fragments from a ring, where separate carbon atoms unite to form alkenes.