2-Trimethylsilylethyl Sulfides in the von Braun Cyanogen Bromide Reaction: Selective Preparation of Thiocyanates and Application to Nucleoside Chemistry
Mixed 2-(trimethylsilyl)ethyl sulfides were synthesized and used in the von Braun cyanogen bromide reaction for preparing selectively thiocyanates in high yield. We show here that this cleavage reaction is highly selective in methanol in comparison with the reaction of the corresponding non-silyl su...
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Published in | Journal of organic chemistry Vol. 67; no. 6; pp. 1898 - 1904 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
22.03.2002
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | Mixed 2-(trimethylsilyl)ethyl sulfides were synthesized and used in the von Braun cyanogen bromide reaction for preparing selectively thiocyanates in high yield. We show here that this cleavage reaction is highly selective in methanol in comparison with the reaction of the corresponding non-silyl sulfide analogues. This reaction was applied to the synthesis of nucleosidic thiocyanates such as the new nucleosides 14 and 18 in the search for mechanism-based inhibitors of ribonucleoside diphosphate reductase and bioactive molecules. The selective cleavage is possible for sulfides bearing hydroxyl functions and aromatic rings. The reactions of cyanogen bromide as cyanating and brominating agent were observed for the first time under the same conditions with the naphthoxyhexyl 2-trimethylsilylethyl sulfide 7, which, treated with cyanogen bromide in dichloromethane, led selectively to the p-bromonaphthoxyhexyl thiocyanate 10 in 89% yield. Another reaction induced by cyanogen bromide was observed in dichloromethane with the 2-(trimethylsilylethyl)thio nucleoside 13, which gives the corresponding symmetrical disulfide 21 in good yield. |
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Bibliography: | istex:17432C2F5C6595BF31F4D3D2D4D1DB85B797FDCD ark:/67375/TPS-0NX670XZ-V ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/jo016200q |