5621-16-9Relevant articles and documents
Cobalt-Catalyzed Enantioselective C–H Arylation of Indoles
Ackermann, Lutz,Jacob, Nicolas,Oliveira, Jo?o C. A.,Wencel-Delord, Joanna,Zaid, Yassir
supporting information, p. 798 - 806 (2022/02/03)
Atropoisomeric (hetero)biaryls are scaffolds with increasing importance in the pharmaceutical and agrochemical industries. Although it is the most obvious disconnection to construct such compounds, the direct enantioselective C–H arylation through the concomitant induction of the chiral information remains extremely challenging and uncommon. Herein, the unprecedented earth-abundant 3d-metal-catalyzed atroposelective direct arylation is reported, furnishing rare atropoisomeric C2-arylated indoles. Kinetic studies and DFT computation revealed an uncommon mechanism for this asymmetric transformation, with the oxidative addition being the rate- and enantio-determining step. Excellent stereoselectivities were reached (up to 96% ee), while using an unusual N-heterocyclic carbene ligand bearing an essential remote substituent. Attractive dispersion interactions along with positive C–H-π interactions exerted by the ligand were identified as key factors to guarantee the excellent enantioselection.
Tandem iridium-catalyzed decarbonylative c-h activation of indole: Sacrificial electron-rich ketone-assisted bis-arylsulfenylation
Kathiravan, Subban,Anaspure, Prasad,Zhang, Tianshu,Nicholls, Ian A.
supporting information, p. 3331 - 3336 (2021/05/29)
Described herein is a decarbonylative tandem C-H bis-arylsulfenylation of indole at the C2 and C4 C-H bonds through the use of pentamethylcyclopentadienyl iridium dichloride dimer ([Cp?IrCl2]2) catalyst and disulfides. A new sacrificial electron-rich adamantoyl-directing group facilitates indole C-H bis-functionalization with a traceless in situ removal. Various differently substituted disulfides can be easily accommodated in this reaction by a coordination to Ir(III) through the formation of six- and five-membered iridacycles at the C2 and C4 positions, respectively. Mechanistic studies show that a C-H activation-induced C-C activation is involved in the catalytic cycle.
Visible-Light-Induced Carbonylation of Indoles with Phenols under Metal-Free Conditions: Synthesis of Indole-3-carboxylates
Qi, Zhuang,Li, Lin,Liang, Ying-Kang,Ma, Ai-Jun,Zhang, Xiang-Zhi,Peng, Jin-Bao
supporting information, p. 4769 - 4773 (2021/06/28)
A visible-light-induced carbonylation of indoles with phenols for the synthesis of indole-3-carboxylates has been developed. The reaction proceeded via a radical carbonylation process in which elementary I2 was used as an effective photosensitive initiator and, thus, avoided the use of transition metal catalysts. A series of different aryl indole-3-carboxylates were prepared in moderate to good yields. The broad applicability of this methodology was further highlighted by the late-stage functionalization of several phenol-containing natural products and pharmaceuticals.
