This unique text gives a detailed introduction into the chemistry of the most important reactive intermediates in modern organic chemistry, such as carbocations, carbanions, radicals, carbenes, carbenoids, nitrenes, arynes, etc. Each chapter is clearly structured and provides information on the formation, identification, structure, stereochemistry as well as stability and reactivity of the intermediates. Additionally, a problem section with different levels of difficulty is included for self-testing. By providing a deeper understanding of the underlying concepts in organic chemistry, this is a must-have reference for PhD and master students in organic chemistry as well as a valuable source of information for chemists in academia and industry working in the field of organic synthesis.