3469-20-3Relevant articles and documents
The first regioselective palladium-catalyzed indolization of 2-bromo- or 2-chloroanilines with internal alkynes: A new approach to 2,3-disubstituted indoles
Shen, Ming,Li, Guisheng,Lu, Bruce Z.,Hossain, Azad,Roschangar, Frank,Farina, Vittorio,Senanayake, Chris H.
, p. 4129 - 4132 (2004)
(Chemical Equation Presented) The first practical and economical process for synthesis of 2,3-disubstituted indole compounds has been developed with high regioselectivity by palladium-catalyzed indolization of 2-bromo- or chloroanilines and their derivatives with internal alkynes.
Rhodium(I)-catalyzed Addition of Tolane to Azobenzene: A New Route to Indole Derivatives
Reisser, P.,Wakatsuki, Y.,Kisch, H.
, p. 1 - 12 (1995)
RhCl(PPh3)3 catalyzes the formation of N-anilino-2,3-diphenylindole (1) and small amounts of 2,3-diphenylindole (2) from azobenzene and diphenylacetylene.Weak acids or silica gel accelerate the reaction and induce an almost quantitative conversion to 1.Other rhodium(I) complexes are less active while rhodium(III) compounds inhibit the reaction.A preliminary reaction mechanism of the homogeneous catalysis is proposed and the structure of two key intermediates is substantiated by ab initio MO calculations. - Keywords: Azobenzene; Diphenylacetylene; Indoles; Rhodium(I)-catalysis; Silica gel supported catalysis.
Synthesis of indolo[2,1-a]isoquinolines via a triazene-directed C-H annulation cascade
Sun, Huan,Wang, Chengming,Yang, Yun-Fang,Chen, Ping,Wu, Yun-Dong,Zhang, Xinhao,Huang, Yong
, p. 11863 - 11872 (2014)
(Chemical Equation Presented) Indole-containing polyaromatic scaffolds are widely found in natural products, pharmaceutical agents, and π-conjugated functional materials. Often, the synthesis of these highly valuable molecules requires a multistep sequence. Therefore, a simple, one-step protocol to access libraries of polyaromatic indole scaffolds is highly desirable. Herein we describe the direct synthesis of polysubstituted indolo[2,1-a]isoquinoline analogues via a double C-H annulation cascade using triazene as an internally cleavable directing group. Evidence from HRMS and theoretical calculations suggests that an unprecedented 1,2-alkyl migration might be responsible for the in situ cleavage of the directing group. Both kinetic isotope effects and DFT calculations suggested that the alkyne insertion step is rate-limiting for the second C,N annulation reaction.
Rh(III)-catalyzed coupling of nitrones with alkynes for the synthesis of indolines
Kong, Lingheng,Xie, Fang,Yu, Songjie,Qi, Zisong,Li, Xingwei
, p. 925 - 932 (2015)
Rh-catalyzed redox-neutral coupling between N-aryl nitrones and alkynes has been achieved under relatively mild conditions. The reaction proceeded via C-H activation at the N-aryl ring with subsequent O-atom transfer, affording trisubstituted indolines in good chemoselectivity and moderate to good diasteroselectivity.
Chiral-Phosphoric-Acid-Catalyzed C6-Selective Pictet-Spengler Reactions for Construction of Polycyclic Indoles Containing Spiro Quaternary Stereocenters
Huang, Wen-Jun,Wang, Han,Wang, Xin-Wei,Wu, Bo,Zhou, Yong-Gui
supporting information, p. 1727 - 1731 (2022/03/14)
Compared with the well-established asymmetric Pictet-Spengler reactions on the pyrrole ring of indoles, the catalytic asymmetric Pictet-Spengler reaction on the benzene ring of indoles has been rarely studied. Herein the C6-selective Pictet-Spengler react
Visible-Light Photocatalytic Tri- A nd Difluoroalkylation Cyclizations: Access to a Series of Indole[2,1- A[isoquinoline Derivatives in Continuous Flow
Yuan, Xin,Duan, Xiu,Cui, Yu-Sheng,Sun, Qi,Qin, Long-Zhou,Zhang, Xin-Peng,Liu, Jie,Wu, Meng-Yu,Qiu, Jiang-Kai,Guo, Kai
supporting information, p. 1950 - 1954 (2021/04/05)
A process for achieving photocatalyzed tri- A nd difluoromethylation/cyclizations for constructing a series of tri-or difluoromethylated indole[2,1-a]isoquinoline derivatives is described. This protocol utilized an inexpensive organic photoredox catalyst and provided good yields. Moreover, the combination of continuous flow and photochemistry, designed to provide researchers with a unique green process, was also shown to be key to allowing the reaction to proceed (product yield of 83% in flow vs 0% in batch).
Sequential Sonogashira/intramolecular aminopalladation/cross-coupling ofortho-ethynyl-anilines catalyzed by a single palladium source: rapid access to 2,3-diarylindoles
Wang, Jiwei,Wang, Gendi,Cheng, Xiang,Liu, Ye,Zhang, Jun
supporting information, p. 1329 - 1333 (2021/02/26)
We have developed a practical and efficient one-pot protocol for the synthesis of 2,3-diarylindolesviaPd-catalyzed bis-arylative cyclization of variouso-ethynylanilines with aryl iodides. Mechanism studies showed that a Pd-catalyzed Sonogashira reaction took place firstly, giving an internal alkyne intermediate, which subsequently underwent intramolecular aminopalladation/cross-coupling to give access to 2,3-diarylindoles. The present methodology exhibits a broad substrate scope, producing various 2,3-diaryl indoles bearing two different aryl groups.
