Ferric(III) Chloride-Promoted Efficient Thiocyanation of Arylalkenes: A Facile Synthesis of Dithiocyanates

Abstract

Anhydrous FeCl₃ oxidizes potassium thiocyanate to the corresponding radical and promotes subsequent addition to nucleophilic olefins to produce dithiocyanate derivatives under mild conditions with high efficiency. Excellent yields and chemoselectivities together with the environmental-friendly nature of the Fe(III) chloride makes this method an attractive alternative to established methods. The use of ferric chloride makes it quite simple, more convenient and practical. This new method offers several advantages such as high conversions, cleaner reaction profiles, short reaction times, and the use of inexpensive and readily available catalyst.

Key words

oxidative radical addition - alkenes - dithiocyanates

References

• 1a Wood JL. In Organic Reactions   Vol. 3:  Wiley; New York: 1967.  p.240-266  
• 1b Kelly TR. Kim MH. Curtis ADM. J. Org. Chem.  1993,  58:  5855 
• 2a Wood JL. Organic Reactions   Vol. 3:  Adams R. John Wiley & Sons; New York: 1946.  Chap. 6.
• 2b Guy RG. In The Chemistry of Cyanates and their Thio Derivatives   Part 2:  Patai S. Wiley; New York: 1977.  Chap. 18. p.819 
• 3 Toste FD. Laronde F. Still WJ. Tetrahedron Lett.  1995,  36:  2949 
• 3 (b) Grant MS. Snyder HR. J. Am. Chem. Soc.  1960,  82:  2742 
• 4 Acetoxythiocyanation of alkenes: Mico AD. Margarita R. Mariani A. Piancatelli G. Chem. Commun.  1997,  1237 
• Preparation of dithiocyanates:
• 5a Mico AD. Margarita R. Mariani A. Piancatelli G. Tetrahedron Lett.  1996,  37:  1889 
• 5b See also: Bruno M. Margarita R. Parlanti L. Piancatelli G. Trifoni M. Tetrahedron Lett.  1998,  39:  3847 
• 5c See also: Nair V. Nair LG. Tetrahedron Lett.  1998,  37:  4585 
• 6a Iodothiocyanation of alkenes: Woodgate PT. Lee HH. Rutledge PS. Tetrahedron Lett.  1976,  1531 
• 6b α-Ketothiocyanation: Nair V. Nair LG. George TG. Augustine A. Tetrahedron  2000,  56:  7607 
• 7a Christoffers J. J. Chem. Soc., Perkin Trans. 1  1997,  3141 
• 7b Christoffers J. Oertling H. Tetrahedron  2000,  56:  1339 
• 7c Lu J. Ma H. Synlett  2000,  63 
• 7d Masson C. Soto J. Bessodes M. Synlett  2000,  1281 
• 7e Chibiryaev AM. Kimpe ND. Tkachev AV. Tetrahedron Lett.  2000,  41:  8011