- Preparation method of 7-alkylindole derivative
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The invention discloses a preparation method of a 7alkyl indole derivative as shown in a formula (4), which comprises the following steps: by using Nprotective indole as shown in a formula (1) and halogenated hydrocarbon as shown in a formula (2) as raw materials, carrying out C-H alkylation reaction by a mechanical grinding method under the action of a manganese catalyst, magnesium metal and an additive, and carrying out deprotection reaction to obtain the 7alkyl indole derivative as shown in the formula; obtaining a 7alkyl indole derivative as shown in a formula (4); according to the method,carrying out cheap metal catalyzed indole C7-site alkylation reaction in a mechanical grinding mode for the first time, the 7alkyl indole derivative is rapidly and efficiently prepared, the adaptability of an indole substrate is greatly widened, and the method has the remarkable advantages of simple reaction system, convenience in operation, mild reaction conditions, specific reaction sites and the like.
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Paragraph 0009; 0022
(2020/12/29)
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- 3-(o-Trifluoroacetamidoaryl)-1-propargylic esters: common intermediates for the palladium-catalyzed synthesis of 2-aminomethyl-, 2-vinylic, and 2-alkylindoles
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3-(o-Trifluoroacetamidoaryl)-1-propargylic esters have been used as common synthetic intermediates for the preparation of a variety of 3-unsubstituted 2-substituted indoles. Treating ethyl 3-(o-trifluoroacetamidoaryl)-1-propargylic carbonates unsubstituted or containing an aryl substituent at the propargylic carbon with piperazines and Pd(PPh3)4 in THF at 80 °C affords 2-(piperazin-1-ylmethyl)indoles in excellent yields. Good to excellent yields of 2-aminomethylindoles are also obtained with other secondary amines. Ethyl 3-(o-trifluoroacetamidoaryl)-1-propargylic carbonates bearing an alkyl substituent at the propargylic carbon and ethyl 3-(o-trifluoroacetamidoaryl)-1-propargylic acetates disubstituted at the propargylic carbon give 2-vinylic indoles with the Pd(OAc)2/PPh3 combination and Et3N in THF at 80 °C. Formation of 2-vinylic indoles is quite stereoselective, generating trans vinylic derivatives, at least with the substrates that we have investigated. In the presence of formic acid, Et3N, and Pd(PPh3)4 in MeCN at 80 °C, ethyl 3-(o-trifluoroacetamidoaryl)-1-propargylic carbonates afford 2-alkylindoles in good to excellent yields.
- Ambrogio, Ilaria,Cacchi, Sandro,Fabrizi, Giancarlo,Prastaro, Alessandro
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scheme or table
p. 8916 - 8929
(2009/12/07)
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- Pd PEPPSI-IPr-mediated reactions in metal-coated capillaries under MACOS: The synthesis of indoles by sequential aryl amination/heck coupling
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A method has been devised for the microwave-assisted, continuous-flow preparation of indole alkaloids by a two-step aryl amination/cross-coupling sequence of bromoalkenes and 2-bromoanilines. This process requires both the presence of a metal-lined flow tube (a 1180 micron capillary) and the Pd PEPPSI-IPr catalyst; without either, the catalyst or the film, there is zero turnover of this catalytic process. A silver film has been shown to provide some conversion (48-62%), but optimal results (quantitative) across a variety of bromoalkenes and bromoanilines were achieved by using a highly porous palladium film. Possible roles for the Pd film are considered, as is the interplay of the catalyst and the film.
- Shore, Gjergji,Morin, Sylvie,Mallik, Debasis,Organ, Michael G.
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p. 1351 - 1356
(2008/09/17)
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- 2-Alkylindoles via palladium-catalyzed reductive cyclization of ethyl 3-(o-trifluoroacetamidophenyl)-1-propargyl carbonates
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The reaction of ethyl 3-(o-trifluoroacetamidophenyl)-1-propargyl carbonates with formate anions in the presence of Pd(PPh3)4 affords 2-alkylindoles in good to excellent yields.
- Ambrogio, Ilaria,Cacchi, Sandro,Fabrizi, Giancarlo
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p. 7721 - 7725
(2008/03/30)
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