Kharasch addition

The Kharasch addition is an organic reaction and a metal-catalysed free radical addition of CXCl3 compounds (X = Cl, Br, H) to alkenes.[1] The reaction was invented by Morris S. Kharasch in the 1940s.[2][3][4]

The basic reaction scheme runs as follows:

RR'CH=CH2 + CXCl3 → RR'CHX-CHCl2X

and proceeds through the CXCl2 free radical. Examples of organohalides are carbon tetrachloride and chloroform. The addition is an anti-Markovnikov addition. Early work linked the addition to olefin polymerization [5] and is therefore considered a first step into what was to become atom transfer radical polymerization.

An example of Karasch addition is the synthesis of 1,1,3-trichloro-n-nonane from 1-octene, chloroform and ferric chloride.[6]

References

  1. ^ Name reactions: a collection of detailed reaction mechanisms, Jie Jack Li Springer; 2nd edition (September 17, 2003) 3540402039
  2. ^ Kharasch, M.; Jensen, E.; Urry, W. (1945). "ADDITION OF CARBON TETRACHLORIDE AND CHLOROFORM TO OLEFINS.". Science 102 (2640): 128. Bibcode 1945Sci...102..128K. doi:10.1126/science.102.2640.128. PMID 17777366.  edit
  3. ^ Kharasch, M. S.; Jensen, E. V.; Urry, W. H. (1947). Journal of the American Chemical Society 69 (5): 1100. doi:10.1021/ja01197a035.  edit
  4. ^ Kharasch, M. S.; Kuderna, B. M.; Urry, W. (1948). "Reactions of atoms and free radicals in solution; the additions of bromodichloromethane and dibromodichloromethane to olefins; the preparation of 2-alkenals". Journal of Organic Chemistry 13 (6): 895–902. doi:10.1021/jo01164a020. PMID 18106035.  edit
  5. ^ Kharasch, M. S.; Urry, W. H.; Jensen, E. V. (1945). Journal of the American Chemical Society 67 (9): 1626. doi:10.1021/ja01225a517.  edit
  6. ^ Organic Syntheses, Coll. Vol. 5, p.1076 (1973); Vol. 45, p.104 (1965). link