Carbenes and Nitrenes
Résumé
This chapter contains sections titled: * Reviews * Generation, Structure, and Reactivity * Carbenes in Coordination Chemistry * Addition–Fragmentations Free Carbenes or Main Group Carbenoids Reactions Transition-Metal-Assisted Reactions * Insertion–Abstraction Free Carbene or Carbenoid Reactions Transition-Metal-Assisted Reactions * Rearrangements Free Carbene or Carbenoid Reactions Transition-Metal-Assisted Reactions * Nucleophilic Carbenes–Carbenes as Organocatalysts Transformations Mediated by Breslow-Type Intermediates Transformations Non-Mediated by Breslow-Type Intermediates * Nitrenes Free Nitrenes – Generation and Reactivity Transition-Metal-Assisted Reactions * Heavy-Atom Carbene Analogues * References This chapter reviews the investigations on carbene reactions by ultrafast photolytic processes revealing mechanistic aspects. It focuses on the dynamic simulations of carbene reaction. The chapter explores the general theme of organocatalysis by car-benes. It presents a short overview of the use of diaminocyclopropylidene. The chapter highlights the fact that organocatalysis by carbene is far from being restricted to N–heterocyclic carbenes (NHCs). It describes the oxidative homocoupling of pyridine-substituted NHC in the coordination sphere of copper. Diazoesters are still among the most relevant precursors of transition-metal car-benoids. Intermolecular NHC–catalysed reactions initiated by the umpolung of an aldehyde continue to be a powerful strategy for the construction of polycyclic skeletons. Computational methods have been used to investigate the formation and the chemical reactivity profile of various sulfonyl nitrenes. The chapter describes the flash vacuum thermolysis (FVT) chemistry and matrix photochemistry of diverse (hetero)aryl nitrenes.