104919-73-5Relevant academic research and scientific papers
One-pot approach to 2,3-disubstituted-2,3-dihydro-4-quinolones from 2-alkynylbenzamides
Okamoto, Noriko,Takeda, Kei,Ishikura, Minoru,Yanada, Reiko
experimental part, p. 9139 - 9143 (2011/12/16)
Concise and efficient syntheses of various trans-2,3-disubstituted-2,3- dihydro-4-quinolones have been achieved via tandem Hofmann-type rearrangement of 2-alkynylbenzamides, nucleophilic addition of alcohols to the isocyanate intermediates, intermolecular
InBr3-promoted divergent approach to polysubstituted indoles and quinolines from 2-ethynylanilines: Switch from an intramolecular cyclization to an intermolecular dimerization by a type of terminal substituent group
Sakai, Norio,Annaka, Kimiyoshi,Fujita, Akiko,Sato, Asuka,Konakahara, Takeo
, p. 4160 - 4165 (2008/09/21)
(Chemical Equation Presented) Use of a 2-ethynylaniline having an alkyl or aryl group on the terminal alkyne selectively produced a variety of polyfunctionalized indole derivatives in moderate to excellent yields via indium-catalyzed intramolecular cyclization of the corresponding alkynylaniline. In contrast, employment of a substrate with a trimethylsilyl group or with no substituent group on the terminal triple bond, exclusively afforded polysubstituted quinoline derivatives in good yields via indium-promoted intermolecular dimerization of the ethynylaniline. This indium catalytic system successfully accommodated the intramolecular cyclization of other arylalkyne skeletons involving a carboxylic acid and an amide group.
Development of an Efficient Procedure for Indole Ring Synthesis from 2-Ethynylaniline Derivatives Catalyzed by Cu(II) Salts and Its Application to Natural Product Synthesis
Hiroya, Kou,Itoh, Shin,Sakamoto, Takao
, p. 1126 - 1136 (2007/10/03)
The development of efficient methods for the indole synthesis catalyzed by Cu(II) salts and its applications were investigated. Cu(OAc)2 has been proved to be the best catalyst for the synthesis of various 1-p-tolylsulfonyl or 1-methylsulfonylindoles, which have both electron-withdrawing and electron-donating groups on the aromatic ring and C2 position of indoles. For the primary aniline derivatives, Cu(OCOCF 3)2 showed good activities, while Cu(OAc)2 was a good catalyst for the cyclization of secondary anilines. This methodology could be applied to the sequential cyclization reaction for the compounds which have the electrophilic part in the same molecule. By prior treatment with KH, the sequential cyclization was realized to provide the tricyclic ring systems, but it was limited to five- and six-membered rings for the second cyclization. Finally, formal and total synthesis of hippadine with the Cu(II)-promoted indole synthesis as the key step was accomplished.
Convenient synthesis of 2-substituted indoles from 2-ethynylanilines with tetrabutylammonium fluoride
Yasuhara, Akito,Kanamori, Yuichi,Kaneko, Masashi,Numata, Atsushi,Kondo, Yoshinori,Sakamoto, Takao
, p. 529 - 534 (2007/10/03)
The cyclization reaction of various 2-ethynylanilines, which were easily synthesized from 2-haloanilines by the palladium-catalyzed reaction with terminal alkynes, with tetrabutylammonium fluoride (TBAF) to yield 2-substituted indoles proceeded at refluxing or room temperature in THF in excellent yields without affecting the bromo, chloro, cyano, ethoxycarbonyl, and ethynyl groups.
Condensed Heteroaromatic Ring Systems. XIII. One-Step Synthesis of 2-Substituted 1-Methylsulfonylindoles from N-(2-Halophenyl)methanesulfonamides
Sakamoto, Takao,Kondo, Yoshinori,Iwashita, Shigeki,Nagano, Tatsuo,Yamanaka, Hiroshi
, p. 1305 - 1308 (2007/10/02)
The reaction of N-(2-bromophenyl)- and N-(2-iodophenyl)methanesulfonamide with terminal acetylenes in the presence of dichlorobis(triphenylphosphine)palladium yielded 1-methylsulfonylindoles having carbon-functional groups at the 2-position, such as hydroxymethyl, 2-hydroxyethyl, diethoxymethyl, 2-ethoxycarbonylethyl, etc., in one step.Keywords - palladium-catalyzed reaction; dichlorobis(triphenylphosphine)palladium; N-(2-halophenyl)methanesulfonamide; acetylene; 2-substituted 1-methylsulfonylindole.
FACILE SYNTHESIS OF 2-SUBSTITUTED INDOLES FROM o-BROMOANILINE
Sakamoto, Takao,Kondo, Yoshinori,Yamanaka, Hiroshi
, p. 31 - 32 (2007/10/02)
The condensation of ethyl o-bromocarbanilate (4) with trimethylsilylacetylene in the presence of dichlorobis(triphenylphosphine)palladium, followed by treatment with sodium ethoxide in boiling ethanol gave indole (3a) in 72percent overall yield from 4.Similarly, 2-substituted indoles (3b,c) were synthesized from 4 and the corresponding 1-alkynes.
