55577-25-8Relevant articles and documents
2-(Methoxycarbonyl)ethyl as a removable N-protecting group: Synthesis of indoloisoquinolinones by pd(II)-catalyzed intramolecular diamination of alkynes
Ha, Tu M.,Yao, Bo,Wang, Qian,Zhu, Jieping
, p. 1750 - 1753 (2015)
Pd(II)-catalyzed double cyclization of 1,2-diarylethynes bearing an N-methyl-N-[2-(methoxycarbonyl)ethyl]amino and an aminocarbonyl group at the ortho positions of the two aromatic rings afforded the tetracyclic N-[2-(methoxycarbonyl)ethyl]indoloisoquinolinones in good to excellent yields. The N-[2-(methoxycarbonyl)ethyl] group is readily removed under basic conditions (DBU, DMF, 120 °C) to afford the corresponding tetracycles with a free indolyl nitrogen in excellent yields. The 2-(methoxycarbonyl)ethyl as a removable N-protecting group is illustrated in other Pd(II)- and Pd(0)-catalyzed and selenium-mediated transformations.
One-Pot Asymmetric Oxidative Dearomatization of 2-Substituted Indoles by Merging Transition Metal Catalysis with Organocatalysis to Access C2-Tetrasubstituted Indolin-3-Ones
Zhao, Yong-Long,An, Jian-Xiong,Yang, Fen-Fen,Guan, Xiang,Fu, Xiao-Zhong,Li, Zong-Qin,Wang, Da-Peng,Zhou, Meng,Yang, Yuan-Yong,He, Bin
, p. 1277 - 1285 (2022/03/14)
A one-pot approach for the asymmetric synthesis of C2-tetrasubstituted indolin-3-ones from 2-substituted indoles was developed via merging transition metal catalysis with organocatalysis. This strategy involves two processes, including CuI catalyzed oxidative dearomatization of 2-substituted indoles using O2 as green oxidant, and followed by an proline-promoted asymmetric Mannich reaction with ketones or aldehydes. A series of C2-tetrasubstituted indolin-3-ones were obtained in 35–86% yields, 2:1->20:1 dr and 48–99% ee. Moreover, the synthetic 2-tetrasubstituted indolin-3-ones could be easily transformed into 1H-[1,3] oxazino [3,4-a]indol-5(3H)-ones via a [4+1] cyclization process. In addition, the synthetic compound 3 s show certain antibacterial activity against S. aureus ATCC25923 and multi-drug resistance bacterial strain of S. aureus (20151027077) and its MIC values up to 8 μg/mL and 16 μg/mL, respectively. (Figure presented.).
Regioselective Direct C2 Arylation of Indole, Benzothiophene and Benzofuran: Utilization of Reusable Pd NPs and NHC-Pd@MNPs Catalyst for C–H Activation Reaction
Hegde, Rajeev V.,Ong, Tiow-Gan,Ambre, Ram,Jadhav, Arvind H.,Patil, Siddappa A.,Dateer, Ramesh B.
, p. 1397 - 1405 (2020/10/02)
Abstract: A regioselective C2 arylation of indoles, benzothiophene and benzofuran without directing group has been accomplished using economically cheap Pd NPs and NHC-Pd@MNPs catalyst. The reusable catalyst is efficiently employed to access C2 arylated heterocycles in good to excellent yield. The reusability of the catalyst is studied up to five cycles and a gram-scale synthesis has been achieved. The reaction mechanism is well supported by control experiments and literature precedents. Grapic Abstract: [Figure not available: see fulltext.]
Palladium-Catalyzed Aminocyclization-Coupling Cascades: Preparation of Dehydrotryptophan Derivatives and Computational Study
Vaz, Belén,Martínez, Claudio,Cruz, Francisco,Denis, J. Gabriel,De Lera, ángel R.,Aurrecoechea, José M.,álvarez, Rosana
, p. 8766 - 8785 (2021/06/30)
Dehydrotryptophan derivatives have been prepared by palladium-catalyzed aminocyclization-Heck-type coupling cascades starting from o-alkynylaniline derivatives and methyl α-aminoacrylate. Aryl, alkyl (primary, secondary, and tertiary), and alkenyl substituents have been introduced at the indole C-2 position. Further variations at the indole benzene ring, as well as the C-2-unsubstituted case, have all been demonstrated. In the case of C-2 aryl substitution, the preparation of the o-alkynylaniline substrate by Sonogashira coupling and the subsequent cyclization-coupling cascade have been performed in a one-pot protocol with a single catalyst. DFT calculations have revealed significant differences in the reaction profiles of these reactions relative to those involving methyl acrylate or methacrylate, and between the reactions of the free anilines and their corresponding carbamates. Those calculations suggest that the nature of the alkene and of the acid HX released in the HX/alkene exchange step that precedes C-C bond formation could be responsible for the experimentally observed differences in reaction efficiencies.
