200345-71-7Relevant academic research and scientific papers
Carboxylic Acid-Promoted Single-Step Indole Construction from Simple Anilines and Ketones via Aerobic Cross-Dehydrogenative Coupling
Ren, Long,Nan, Guanglei,Wang, Yongcheng,Xiao, Zhiyan
, p. 14472 - 14488 (2018)
The cross-dehydrogenative coupling (CDC) reaction is an efficient strategy for indole synthesis. However, most CDC methods require special substrates, and the presence of inherent groups limits the versatility for further transformation. A carboxylic acid-promoted aerobic catalytic system is developed herein for a single-step synthesis of indoles from simple anilines and ketones. This versatile system is featured by the broad substrate scope and the use of ambient oxygen as an oxidant and is convenient and economical for both laboratory and industry applications. The existence of the labile hydrogen at C-3 and the highly transformable carbonyl at C-2 makes the indoles versatile building blocks for organic synthesis in different contexts. Computational studies based on the density functional theory (DFT) suggest that the rate-determining step is carboxylic acid-assisted condensation of the substrates, rather than the functionalization of aryl C-H. Accordingly, a pathway via imine intermediates is deemed to be the preferred mechanism. In contrast to the general deduction, the in situ formed imine, instead of its enamine isomer, is believed to be involved in the first ligand exchange and later carbopalladation of the α-Me, which shed new light on this indolization mechanism.
Synthesis method for preparing 2-substituted indole derivative
-
Paragraph 0167-0170, (2019/05/28)
The invention relates to a synthesis method for preparing a 2-substituted indole derivative. The method includes the following steps: mixing aromatic amine compounds (I), ketone compounds (II) and a drying agent in an organic solvent; adding a palladium catalyst; and reacting in an aerobic weak acid environment to prepare the indole compounds (III). (I), (II) and (III) are as shown in the specification, wherein R1 is selected from hydrogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkanoyl, C2-C6 alkenyl, C2-C6 alkynyl, halogen, hydroxyl, substituted or unsubstituted amino, substituted or unsubstituted phenyl, pyridyl and heterocyclic aryl; (I) can be pyridylamine, pyrimidylamine, pyridazinam or pyrazinamide which may further be substituted or unsubstituted; and the substituents are selected fromone or more C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkanoyl, C2-C6 alkenyl, C2-C6 alkynyl, halogen, hydroxyl, amino; and R2 is selected from C1-C6 alkyl, formate groups or C1-C6 alkylamide groups.
Synthesis of Indole-2-carboxylate Derivatives via Palladium-Catalyzed Aerobic Amination of Aryl C-H Bonds
Clagg, Kyle,Hou, Haiyun,Weinstein, Adam B.,Russell, David,Stahl, Shannon S.,Koenig, Stefan G.
supporting information, p. 3586 - 3589 (2016/08/16)
A direct oxidative C-H amination affording 1-acetyl indolecarboxylates starting from 2-acetamido-3-arylacrylates has been achieved. Indole-2-carboxylates can be targeted with a straightforward deacetylation of the initial reaction products. The C-H amination reaction is carried out using a catalytic Pd(II) source with oxygen as the terminal oxidant. The scope and application of this chemistry is demonstrated with good to high yields for numerous electron-rich and electron-poor substrates. Further reaction of selected products via Suzuki arylation and deacetylation provides access to highly functionalized indole structures.
ZrCl4-promoted facile synthesis of indole derivatives
Tummatorn,Gleeson,Krajangsri,Thongsornkleeb,Ruchirawat
, p. 20048 - 20052 (2014/05/20)
Zirconium(iv) chloride effectively activates nitrogen (N2) extrusion from aryl azidoacrylates followed by annulation to provide the desired indole products in moderate to good yields. The reaction proceeds at low temperature and in short reaction time and is applicable to a variety of substrates.
Synthesis of (E)-8-(3-chlorostyryl)caffeine analogues leading to 9-deazaxanthine derivatives as dual A2A antagonists/MAO-B inhibitors
Rivara, Silvia,Piersanti, Giovanni,Bartoccini, Francesca,Diamantini, Giuseppe,Pala, Daniele,Riccioni, Teresa,Stasi, Maria Antonietta,Cabri, Walter,Borsini, Franco,Mor, Marco,Tarzia, Giorgio,Minetti, Patrizia
, p. 1247 - 1261 (2013/04/10)
A systematic modification of the caffeinyl core and substituents of the reference compound (E)-8-(3-chlorostyryl)caffeine led to the 9-deazaxanthine derivative (E)-6-(4-chlorostyryl)-1,3,5,-trimethyl-1H-pyrrolo[3,2-d]pyrimidine- 2,4-(3H,5H)-dione (17f), w
New findings on the hemetsberger-knittel reaction (synthetic studies on indoles and related compounds. XLIII(1))
Murakami, Yasuoki,Watanabe, Toshiko,Suzuki, Hideharu,Kotake, Nobuyo,Takahashi, Tomoko,Toyonari, Kiyono,Ohno, Masami,Takase, Kyoko,Suzuki, Takayuki,Kondo, Kazuhiro
, p. 1739 - 1744 (2007/10/03)
In the Hemetsberger-Knittel reaction for indole synthesis, the intermediate ethyl 2-azido-3-hydroxy-3-aryl-propionate (4) was found to be formed in the reaction of arylaldehyde 1 with ethyl azidoacetate at a lower temperature (-30°C) as the main product,
