1018967-76-4Relevant articles and documents
Intermolecular Cope-type hydroamination of alkenes and alkynes using hydroxylamines
Moran, Joseph,Gorelsky, Serge I.,Dimitrijevic, Elena,Lebrun, Marie-Eve,Bedard, Anne-Catherine,Seguin, Catherine,Beauchemin, Andre M.
supporting information; experimental part, p. 17893 - 17906 (2009/07/18)
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-Alkylhydroxy-lamines 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.
Intermolecular cope-type hydroamination of alkenes and alkynes
Beauchemin, Andre M.,Moran, Joseph,Lebrun, Marie-Eve,Seguin, Catherine,Dimitrijevic, Elena,Zhang, Lili,Gorelsky, Serge I.
, p. 1410 - 1413 (2008/12/23)
(Chemical Equation Presented) Keep it simple! Intermolecular hydroamination can be achieved simply upon heating alkynes and alkenes with aqueous hydroxylamine. Alkynes react to afford oximes in good to excellent yields, and the formation of Markovnikov products is favored. A mechanism involving Cope-type hydroamination followed by bimolecular proton transfer is suggested and supported by DFT studies.
