Introduction
Carbocations are positively charged carbon-centered reactive intermediates. Although they were considered to be relatively unstable and transient species, Olah’s extensive work in 1960s reveal that some carbocations can be long-lived species in superacid media [1]. Various carbocations were generated and accumulated in superacid, and they were characterized by NMR spectroscopy. However, the nature of carbocations in conventional reaction media, which are used for organic synthesis, has not been fully clarified as yet.
To generate carbocations for preparative purposes, there are two methods, that is, acid promoted reaction (Scheme 1a) and oxidative reaction (Scheme 1b). Acid-promoted reactions are the most commonly used for the generation of carbocations. In this method, a proton or a Lewis acid is used to activate a leaving group, and then the heterolysis of the bond between the carbon and the leaving group occurs to generate the carbocation. Because these steps are...
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References
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Suga, S. (2014). Cation-Pool Method. In: Kreysa, G., Ota, Ki., Savinell, R.F. (eds) Encyclopedia of Applied Electrochemistry. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-6996-5_342
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