A diastereodivergentasymmetric Michael-alkylation reaction between 3-chloro-oxindoles and β,γ-unsaturated-α-ketoesters has been achieved using L-RaPr2/Sc(OTf)3 and L-PrPr2/Mg(OTf)2 metal complexes as catalysts. Both rel-(1R,2S,3R) and rel-(1S,2S,3R) chiral spiro cyclopropane oxindoles were constructed in good yields, diastereoselectivities and ee values. The diastereodivergent control may originate
Controllable transformation of indoles using iodine(<scp>iii</scp>) reagent
作者:Yinxiang Jian、Peng Liang、Xiaoyan Li、Huawu Shao、Xiaofeng Ma
DOI:10.1039/d2ob01951e
日期:——
combination of phenyliodinebis(trifluoroacetate) (PIFA) with n-Bu4NCl·H2O (TBAC) was exploited. Through controlling the amount of PIFA and TBAC from one to three equivalents, 3-chloro-indoles, 3-chloro-2-oxindoles, and 3,3-dichloro-2-oxindoles were obtained, respectively, in satisfactory to excellent yields. The advantages of the protocol include mild conditions, facile process with short reaction time, high
Asymmetric Organocatalytic Synthesis of Spiro-cyclopropaneoxindoles
作者:Tõnis Kanger、Artur Noole、Andrei Malkov
DOI:10.1055/s-0033-1338505
日期:——
Straightforward cascade reactions for the synthesis of spiro-cyclopropaneoxindoles are described. The target compounds are obtained in high yields and in good enantio- and diastereoselectivities via hydrogen bonding or iminium catalysis.
Guillaumel, Jean; Demerseman, Pierre; Clavel, Jean-Marc, Journal of Heterocyclic Chemistry, 1980, vol. 17, # 6, p. 1531 - 1536