Room temperature iron(<scp>ii</scp>)-catalyzed radical cyclization of unsaturated oximes with hypervalent iodine reagents
作者:Shichao Yang、Hongji Li、Pinhua Li、Jingya Yang、Lei Wang
DOI:10.1039/c9ob02424g
日期:——
Here, we disclose an iron(ii)-catalyzed I-O bond cleavage of Koser's hypervalent iodine reagents (HIRs) that initiated the radical cyclization of unsaturated oximes at room temperature. This strategy is successfully applied for the construction of the isoxazoline backbone in an efficient manner. In particular, the direct introduction of a TsO group into products facilitates their late-stage transformations
A copper-catalyzed oxydifluoroalkylation of β,γ-unsaturatedoximes has been developed. This reaction proceeded through a cascade of difluoroalkylation of alkene followed by nucleophilic attack of the hydroxyl group of oximes. This protocol features mild reaction conditions, low-cost catalyst, and broad substrate scope, which provides a facile method to synthesize isoxazolines with a fluorinated sidechain
A highly efficient copper-catalyzed cyclization/cyanation cascade of unactivated olefins bearing oximes is described. A variety of cyano-containing isoxazolines have been obtained in high yields with cheap Cu(NO3)2·3H2O as the catalyst and TMSCN as the non-metallic cyanide source. The present method provides a mild, simple, and practical access to cyano-substituted isoxazolines and is amenable to gram
radicals has been accomplished under oxidant-free conditions. This approach offers a mild, atom-economical, and redox-neutral synthesis of 5-methylisoxazolines through radical hydroxygenation of β,γ-unsaturatedoximes in the absence of an additional hydrogen source.