6. Photogeneration of Carbocations and Carbanions

  1. Angelo Albini and
  2. Maurizio Fagnoni

Published Online: 12 JUL 2013

DOI: 10.1002/9781118689202.ch06

Photochemically-Generated Intermediates In Synthesis

Photochemically-Generated Intermediates In Synthesis

How to Cite

Albini, A. and Fagnoni, M. (eds) (2013) Photogeneration of Carbocations and Carbanions, in Photochemically-Generated Intermediates In Synthesis, John Wiley & Sons, Inc., Hoboken, New Jersey. doi: 10.1002/9781118689202.ch06

Editor Information

  1. PhotoGreen Lab, Department of Chemistry, University of Pavia, Pavia, Italy

Publication History

  1. Published Online: 12 JUL 2013
  2. Published Print: 23 AUG 2013

ISBN Information

Print ISBN: 9780470915349

Online ISBN: 9781118689202



  • alkyl cations;
  • carbanions;
  • phenyl cations;
  • photogeneration;
  • photoheterolysis;
  • vinyl cations


This chapter deals with the photogeneration of carbocations and carbanions and their applications. The photochemical approach has a significant role for the generation of different kinds of alkyl, vinyl, and aryl cations under mild conditions. The main pathways for the photogeneration of alkyl cations are the photoheterolysis of alkyl-halogen bonds and the photoinduced addition of a proton onto an alkene. The most common way for arriving at vinyl cations by photochemical means involves the photoheterolytic cleavage of the C-X bond in vinyl halides. The intermediacy of a phenyl cation formed from neutral precursors was claimed in a number of photosubstitution reactions. Photochemistry of aryl cations has been developed in a nonsynthetic direction, since these intermediates play an important role in the photodegradation of fluoroquinolone and oxazolidinone antibiotics.