6943-01-7Relevant articles and documents
Enantioselective Construction of Spirooxindole-Fused Cyclopentanes
Do?ekal, Vojtěch,Vopálenská, Andrea,Měrka, Pavel,Kone?ná, Klára,Jand'Ourek, Ond?ej,Pour, Milan,Císa?ová, Ivana,Vesely, Jan
, p. 12623 - 12643 (2021/07/31)
The present study reports an asymmetric organocatalytic cascade reaction of oxindole derivates with α,β-unsaturated aldehydes efficiently catalyzed by simple chiral secondary amine. Spirooxindole-fused cyclopentanes were produced in excellent isolated yields (up to 98%) with excellent enantiopurities (up to 99% ee) and moderate to high diastereoselectivities. The synthetic utility of the protocol was exemplified on a set of additional transformations of the corresponding spiro compounds. In addition, a study showing the promising biological activity of selected enantioenriched products was accomplished.
A convenient synthesis of indole and 1,4-dihydropyridine hybrid macromolecules by dimerization of [2-(1h-indol-3-yl)ethyl]pyridinium salts
Ling, Gang,Zhang, Jing,Zhang, Rong-Zheng,Han, Fu-She
, p. 67 - 73 (2018/01/26)
The design and synthesis of a novel type of macrocyclic compounds containing indole and 1,4-dihydropyridine heterocyclic subunits is presented. The key reaction involved in the synthesis was a base-mediated dimerization of [2-(1H-indol-3-yl)ethyl]pyridinium salts. The structure of the macrocycles was unambiguously confirmed by NMR and HRMS spectroscopic and X-ray single crystal diffraction.
Aqueous Titanium Trichloride Promoted Reductive Cyclization of o-Nitrostyrenes to Indoles: Development and Application to the Synthesis of Rizatriptan and Aspidospermidine
Tong, Shuo,Xu, Zhengren,Mamboury, Mathias,Wang, Qian,Zhu, Jieping
, p. 11809 - 11812 (2015/10/05)
Treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)-H amination process. A range of functions such as halides (Cl, Br), carbonyl (ester, carbamate), cyano, hydroxy, and amino groups were tolerated. From β,β-disubstituted o-nitrostyrenes, 2,3-disubstituted indoles were formed by a domino reduction/cyclization/migration process. Mild conditions, simple experimental procedure, ready accessibility of the starting materials and good to excellent yields characterize the present transformation. The methodology was used as a key step in a concise synthesis of rizatriptan and a formal total synthesis of aspidospermidine. Mild and efficient treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)-Hamination process. A concise synthesis of a marketed drug (rizatriptan) and a formal total synthesis of aspidospermidine featuring this novel N-heterocyclization process are reported.