Intermolecular Cope-Type Hydroamination of Alkenes and Alkynes using Hydroxylamines
| Autor: | Andre M. Beauchemin, Elena Dimitrijevic, Anne‐Catherine Bedard, Joseph Moran, Catherine Seguin, Marie-Eve Lebrun, Serge I. Gorelsky |
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| Rok vydání: | 2008 |
| Předmět: |
Aqueous solution
Sodium cyanoborohydride Intermolecular force Markovnikov's rule General Chemistry Alkenes Hydroxylamines Biochemistry Combinatorial chemistry Catalysis Metal chemistry.chemical_compound Colloid and Surface Chemistry Hydroxylamine chemistry Cyclization Alkynes visual_art Oximes visual_art.visual_art_medium Thermodynamics Reactivity (chemistry) Hydroamination Amination |
| Zdroj: | Journal of the American Chemical Society. 130:17893-17906 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja806300r |
| Popis: | The development of the Cope-type hydroamination as a method for the metal- and acid-free intermolecular hydroamination of hydroxylamines with alkenes and alkynes is described. Aqueous hydroxylamine reacts efficiently with alkynes in a Markovnikov fashion to give oximes and with strained alkenes to give N-alkylhydroxylamines, while unstrained alkenes are more challenging. N-Alkylhydroxylamines also display similar reactivity with strained alkenes and give modest to good yields with vinylarenes. Electron-rich vinylarenes lead to branched products while electron-deficient vinylarenes give linear products. A beneficial additive effect is observed with sodium cyanoborohydride, the extent of which is dependent on the structure of the hydroxylamine. The reaction conditions are found to be compatible with common protecting groups, free OH and NH bonds, as well as bromoarenes. Both experimental and theoretical results suggest the proton transfer step of the N-oxide intermediate is of vital importance in the intermolecular reactions of alkenes. Details are disclosed concerning optimization, reaction scope, limitations, and theoretical analysis by DFT, which includes a detailed molecular orbital description for the concerted hydroamination process and an exhaustive set of calculated potential energy surfaces for the reactions of various alkenes, alkynes, and hydroxylamines. |
| Databáze: | OpenAIRE |
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