Molybdenum-Catalyzed Asymmetric Allylation of 3-Alkyloxindoles: Application to the Formal Total Synthesis of (−)-Physostigmine
作者:Barry M. Trost、Yong Zhang
DOI:10.1021/ja060560j
日期:2006.4.1
The first example of Mo-catalyzed asymmetric allylation for the generation of quaternary stereocenters at a prochiral nucleophile is reported. A variety of 3-alkyl oxindoles can be alkylated with high yields and enantioselectivity. This method provides expedited access to (-)-physostigmine and its analogues.
报道了第一个在前手性亲核试剂上产生四元立体中心的 Mo 催化不对称烯丙基化的例子。多种 3-烷基羟吲哚可以以高产率和对映选择性进行烷基化。该方法提供了对 (-)-毒扁豆碱及其类似物的快速访问。
FeCl<sub>3</sub>-Catalyzed Allylation Reactions onto 3-Hydroxy-2-oxindoles: Formal Total Syntheses of Bis-cyclotryptamine Alkaloids, (±)-Chimonanthine, and (±)-Folicanthine
作者:Lakshmana K. Kinthada、Sai Raghavendra Medisetty、Amarchand Parida、K. Naresh Babu、Alakesh Bisai
DOI:10.1021/acs.joc.7b01232
日期:2017.8.18
presents an efficient and concise access to the pyrroloindoline alkaloids (±)-deoxyeseroline (1a), (±)-esermethole (1b), (±)-physostigmine (1c), (±)-phenserine (1d), and (±)-physovenine (1e). Eventually, we extrapolated the scope of this methodology to the formal total syntheses of dimeric cyclotyrptamine alkaloids (±)-chimonanthine (3a), (±)-folicanthine (3c), and (±)-calycanthine (4).
Synthesis of 3,3-disubstituted oxindoles by one-pot integrated Brønsted base-catalyzed trichloroacetimidation of 3-hydroxyoxindoles and Brønsted acid-catalyzed nucleophilic substitution reaction
作者:Cyril Piemontesi、Qian Wang、Jieping Zhu
DOI:10.1039/c2ob27196f
日期:——
Treatment of 3-hydroxyoxindoles with trichloroacetonitrile (1.3 equiv.) and a catalytic amount of DBU (0.1 equiv.) followed by addition of nucleophiles (1.5 equiv.) and diphenylphosphoric acid (0.2 equiv.) afforded the 3,3-disubstituted oxindoles in good to excellent yields. DFT computations supported the notion that the reaction went through the 1-alkyl-2-oxo-2H-indol-1-ium intermediate.