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DOI: 10.1055/s-2007-968424
Unsymmetrical Sulfides, Selenides, and Tellurides from Organoboronic Acids
Contributor(s):Paul Knochel, Andrei GavryushinFukushima Medical University, Japan
Convenient Synthesis of Unsymmetrical Organochalcogenides Using Organoboronic Acids with Dichalcogenides via Cleavage of the S-S, Se-Se, Te-Te Bond by a Copper Catalyst
J. Org. Chem. 2007, 72: 1241-1245
Publication History
Publication Date:
24 April 2007 (online)
Key words
unsymmetrical sufides and selenides - organoboronic acids - copper
Significance
This procedure allows a convenient and general transformation of various organoboronic acids into unsymmetrical sulfides, selenides, or tellurides. The mild reaction conditions ensure an excellent functional group tolerance, thus making this reaction useful for the combinatorial-like synthesis of biologically relevant molecules. The best yields are achieved with aryl chalcogenides and arylboronic acids; nevertheless, the scope of suitable substrates is quite broad. This is one of few useful methods for the preparation of unsymmetrical selenides and tellurides.
Comment
In the suggested reaction mechanism, the R1B(OH)2 is first converted into R1Cu(I), which reacts with (R2S)2 or its analogue to give R1SR2 and R2SCu, which after the oxidation by O2 reacts with another molecule of an organoboron compound. The reaction, therefore, requires the presence of air. Dichalcogenides are much easier to handle than the corresponding thiols or selenols, as they are not air-sensitive.
Review
For a review on the Cu-mediated aryl-heteroatom bond formation, see: S. V. Ley, A. W. Thomas Angew. Chem. Int. Ed. 2003, 42, 5400-5449.