30218-58-7Relevant articles and documents
Rhodium-Catalyzed Stereoselective Cyclization of 3-Allenylindoles and N-Allenyltryptamines to Functionalized Vinylic Spiroindolenines
Becker, Antonia,Breit, Bernhard,Grugel, Christian P.
supporting information, p. 3788 - 3792 (2021/05/29)
Herein, we report a highly enantio- and diastereoselective rhodium-catalyzed cyclization of N-allenyltryptamines and 3-allenylindoles to 6-membered spirocyclic indolenines. This allylic addition methodology offers the advantage of using a comparably cheap commercially available ligand with low loadings of an affordable rhodium precursor. The products can be converted into functionalized spirooxindoles and spiroindolines, which are regarded as important building blocks for the synthesis of a lot of natural products with biological activities.
I2-induced cascade cyclization and dearomatization of indoles for the highly efficient synthesis of iodinated and vinylic spiroindolenines
Li, Yazhou,Liang, Xuewu,Liu, Hong,Liu, Qi,Liu, Xuyi,Wei, Xiaohui,Zhou, Yu
supporting information, p. 9165 - 9171 (2021/11/23)
The spiroindolenine framework is a privileged heterocyclic motif and is widely present in numerous indole alkaloids. Herein, we develop a metal-free and environmentally friendly approach for the intramolecular cascade cyclization and dearomatization of indole derivatives to selectively afford iodinated and vinylic spiroindolenines by a substrate-controlled strategy. Simple operation, mild conditions, and high yield make this strategy a green and attractive pathway to construct functionalizable spiroindolenine scaffolds, which could be converted into diverse useful spiroindolenine derivatives.
Rhodium-Catalyzed Diastereo- And Enantioselective Tandem Spirocyclization/Reduction of 3-Allenylindoles: Access to Functionalized Vinylic Spiroindolines
Grugel, Christian P.,Breit, Bernhard
supporting information, p. 9672 - 9676 (2019/12/24)
A highly selective rhodium-catalyzed tandem spirocyclization/reduction of 3-allenylindoles is reported. By employing a Hantzsch ester as reductant, vinylic spiroindolines are obtained in excellent yields as well as diastereo- and enantioselectivity. In addition, the reaction's synthetic utility is highlighted by broad functional group compatibility and exemplified by a gram scale reaction with subsequent assorted transformations.