468715-01-7Relevant academic research and scientific papers
Tin-mediated free-radical cyclization of β-allenylbenzoyloximes
Depature, Michael,Diewok, Josef,Grimaldi, Jacques,Hatem, Jacques
, p. 275 - 280 (2000)
A set of allene-tethered benzoyloximes (5) has been treated with nBu3SnH. Depending on their substitution pattern, a wide range of compounds has been obtained. If the stannyl radical adds on the allene, the C-centred radical thus formed undergoes either a 5-exo ring closure to give the cyclopentene derivatives 7 or a 6-endo ring closure onto the N atom to give the dihydropyridines 8. If the stannyl radical adds on the benzoyl moiety, an iminyl radical is formed which leads to the 3H-pyrroles 9 and the alkylidene- pyrrolines 10. Steric effects as well as polar effects are the factors governing the reaction course.
3,6-dihydropyridines from 6-endo radical cyclisation onto nitrogen in β-allenyl ketoximebenzoates
Depature, Michael,Siri, Didier,Grimaldi, Jacques,Hatem, Jacques,Faure, Robert
, p. 4547 - 4550 (2007/10/03)
When tosyl bromide is added under free radical conditions to β-allenyl- 1-phenylketoximebenzoates, a carbon-centred radical resulting from the addition of the tosyl radical on the sp carbon is formed. Depending on the substitution pattern of the allenyl moiety, this carbon-centred radical traps a bromine atom or undergoes a rare 6-endo cyclisation onto the nitrogen atom leading to 3,6-dihydropyridines in good yields.
