Reactions involving selenium metal as an electrophile: Scope and limitations of the enolate-selenolate transformation
✍ Scribed by Kevin Swiss; Woo-Baeg Choi; Julie Mohan; Christopher Barnum; Manohar Saindane; George Zima; Dennis Liotta
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 597 KB
- Volume
- 1
- Category
- Article
- ISSN
- 1042-7163
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✦ Synopsis
When lithium enolates are allowed to react with selenium metal, selenolate (selenide) ions are formed. Al- kylation of these selenolate ions produces the corresponding a-alkylselenenyl carbonyl derivatives. These derivatives can then be converted to their unsaturated counterparts using the same type ofprotocols that are employed with arylselenenyl derivatives.
With the exception of selenium dioxide, prior to 1970 selenium reagents were rarely employed in organic synthesis. However, over the past 20 years their use has increased dramatically. Through the use of organoselenium methodology, a variety of important chemical transformations can be accomplished in higher efficiency than alternative methods [l]. This generalization becomes all the more remarkable when one considers that seleniumcontaining species are almost never synthetic targets in their own right, but instead are intermediates which are prepared en route to some non-selenium-containing substrate. Thus, in order for organoselenium methodology to be superior to other approaches, protocols involving the introduction, manipulation, and ultimate extrusion of selenium must take place with a combined efficiency that is greater than available by other methods.
Without question, the single, most useful application of organoselenium chemistry involves the introduction of double bonds via selenoxide elimi-~~~~~ * To whom correspondence should be addressed.