27182-26-9Relevant academic research and scientific papers
Novel Photocycloadditions of Electron-Deficient Nitrones to 2-Methyl-2-butene
Sehgal, R. K.,Griffin, G. W.
, p. 513 - 517 (2007/10/02)
In order to decrease the ground state reactivity and increase their potential for cycloadditions, cyano- and methoxycarbonyl-substituted nitrones 1a and 1b, respectively, were prepared and irradiated in the presence of electron-rich alkenes such as 2 to afford the corresponding oxazolidines in which the oxygen atom becomes attached to the least substituted terminus of the olefin and nitrogen attaches the more highly substituted counterpart.While the oxazolidines 12a and 12b obtained from 1b, via the intermediacy of oxaziridine(s) 15 and subsequent N-O bond scission, are isolated and characterized, the oxazolidine(s) 18 formed by cycl ization of 1a are more labile and may undergo ionization to the stabilized oxazolinium ion 19 followed by nucleophilic attack by cyanide ion with accompanying ring opening to afford 6.A sequential diradical mechanism is proposed to rationalize the formation of the observed photoproducts 5 and 6.
