31676-43-4Relevant academic research and scientific papers
A three-step, highly enantioselective synthesis of (R)-2-methyl tryptophane ethyl ester: Comparison with chemical resolution
Solladie-Cavallo, Arlette,Schwarz, Johanes,Mouza, Cyrille
, p. 3861 - 3864 (1998)
(R)-2-Methyltryptophan ethyl ester, (R)-2, having an enantiomeric purity >,=96% was obtained in 3 steps and using (SSS)-hydroxypinanone, 1, as the recoverable chiral auxiliary. The synthesis of the alkylating agent, 5a, was improved (to a reproduceble 55% overall yield from 2,3-dimethylindole). The resolution of racemic-2 through chromatographic separation of the corresponding iminoester derived from (RRR)-1 also proved to be easy and efficient (-25% yield).
Intramolecular cooperative C-C bond cleavage reaction of 1,3-dicarbonyl compounds with 2-iodoanilines to give o-(N-Acylamino)aryl ketones and multisubstituted indoles
Xing, Qi,Lv, Hui,Xia, Chungu,Li, Fuwei
, p. 8591 - 8596 (2015/06/02)
A copper-catalyzed C-C bond cleavage reaction of 1,3-dicarbonyl compounds with 2-iodoanilines was developed. In this process, the ortho effect played an important role in the reactivity and a new reaction pathway that involved a (2-aminophenyl)-bis-(1,3-dicarbonyl) copper species was clearly observed by a time-course HRMS analysis of the reaction mixture. Unlike the previous reports, both the nucleophilic and electrophilic parts of the 1,3-dicarbonyl compound were coupled with 2-iodoaniline by C-C bond cleavage to form o-(N-acylamino)aryl ketones, which could be efficiently converted into multisubstituted indoles.
Regioselective hydroarylation reactions of C3 electrophilic N-acetylindoles activated by FeCl3: An entry to 3-(Hetero)arylindolines
Beaud, Rodolphe,Guillot, Regis,Kouklovsky, Cyrille,Vincent, Guillaume
supporting information, p. 7492 - 7500 (2014/06/23)
A method for the direct and rare umpolung of the 3 position of indoles is reported. The activation of N-acetylindole with iron(III) chloride allows the C-H addition of aromatic and heteroaromatic substrates to the C2-C3 double bond of the indole nucleus to generate a quaternary center at C3 and leads regioselectively to 3-arylindolines. Optimization, scope (50 examples), practicability (gram scale, air atmosphere, room temperature), and mechanistic insights of this process are presented. Synthetic transformations of the indoline products into drug-like compounds are also described.
Dirhodium(II) carboxylate catalyzed formation of 1,2,3-trisubstituted indoles from styryl azides
Jones, Crystalann,Nguyen, Quyen,Driver, Tom G.
supporting information, p. 785 - 788 (2014/01/23)
Dirhodium(II)-carboxylate complexes were discovered to promote the selective migration of acyl groups in trisubstituted styryl azides to form 1,2,3-trisubstituted indoles. The styryl azides are readily available in three steps from cyclobutanone and 2-iod
Rh(III)-catalyzed tandem C-H allylation and oxidative cyclization of anilides: A new entry to indoles
Cajaraville, Ana,Lopez, Susana,Varela, Jesus A.,Saa, Carlos
supporting information, p. 4576 - 4579 (2013/09/24)
RhIII-catalyzed tandem C-H allylation and oxidative cyclization of anilides with allyl carbonates in the presence of a slight excess of AgSbF6 salt and Cu(OAc)2 as oxidant affords easy, economical access to important bioac
Reactions of N-Acylated Indoles with Singlet Oxygen
Zhang, Xiaojun,Foote, Christopher S.,Khan, Saeed I.
, p. 47 - 51 (2007/10/02)
Reactions of seven N-acyl indole derivatives with singlet oxygen have been investigated. 1-Acetyl-(1a) and 1-(chloroacetyl)-2,3-dimethylindole (1b) gave exclusively 1-acetyl- (2a) and 1-(chloroacetyl)-2-hydroperoxy-3-methyleneindoline (2b), respectively, in high yields via ene reaction on irradiation with oxygen in the presence of TPP sensitizer. 1-Acetyl-3-methylindole (1c) gave only 1-acetyl-2-hydroperoxy-3-methyleneindoline (2c) in low yield under the same conditions.In contrast, 1-acetyl-2-methyl-3-ethylindole (3a) and 1-acetyl-2-methyl-3-isopropylindole (3b) gave a mixture of ene products, 2-hydroperoxy- and 3-hydroperoxyindolines (4a and b and 5a and b), in addition to 2,3-bond cleavage products 6a and 6b, respectively.In the case of 1-acetyl-2-methyl-3-tert-butylindole (7), only the product of 2,3-bond cleavage (8) was obtained.A 1,2-dioxetane is intermediate in the cleavage and could be observed after photooxygenation of 7 at -5 deg C by NMR and was reduced by trimethylphosphite and dimethyl sulfide.The decomposition rate constant of 1,2-dioxetane 10 was measured by NMR; Ea is 24.6 kcal/mol.
Reactions of Electron-rich Heterocycles with Orthocarboxylic Acid Derivatives, 9. - Acylation of Indole and Methylindoles with Dialkoxycarbenium Tetrafluoroborates
Pindur, Ulf,Flo, Camran,Akguen, Eyuep,Tunali, Mustafa
, p. 1621 - 1627 (2007/10/02)
Indole and some methylindoles 1 were acylated regioselectively with dialkoxycarbenium tetrafluoroborates 2 under mild conditions.The formyl cation equivalent 2a' reacts with excess of indoles 1 to give the bisindolylcarbenium tetrafluoroborates 13a-d.
A CONVENIENT SYNTHETIC METHOD OF 1-ACYL-2-ARYL-3,3-DIMETHYLINDOLINE INVOLVING ISOLABLE DIASTEREOMERIC ATROPISOMERS
Kitamura, Takeo,Koga, Toshitaka,Taguchi, Tanezo,Harano, Kazunobu
, p. 1315 - 1318 (2007/10/02)
The synthesis of 1-acyl-2-aryl-3,3-dimethylindoline was improved by the reaction of 1-acyl-2-hydroxy-3,3-dimethylindoline with an arene in the presence of BF3*O(C2H5)2 in dioxane, and stable diastereomeric atropisomers were isolated as products when the a
Effect of steric factors in the heterogeneous-catalytic E. Fischer reaction. XII. Heterogeneous-catalytic E. Fischer reaction
Suvorov, N. N.,Shkil'kova, V. N.,Podkhalyuzina N. Ya.
, p. 649 - 652 (2007/10/02)
The effect of steric factors on the indolization under the conditions of heterogeneous catalysis was investigated for the case of a series of N-alkyl- and N-aryl-substituted phenylhydrazones of methyl ethyl ketone.There is a definite correlation between the stereochemical structure of the arylhydrazones and their ability to undergo cyclization to the corresponding indole.
