61-70-1Relevant academic research and scientific papers
Thermally induced reaction of diazoamides with isatins: A complementary approach to the 3,3′-bioxindole derivatives
Zheng, Yang,Bao, Ming,Qiu, Lihua,Xu, Xinfang
, p. 3390 - 3393 (2017)
An efficient and thermally induced reaction of diazoamide with isatin under mild reaction conditions is described, which provides a complementary approach to the 3,3′-bioxindole in high yields with excellent diastereoselectivity. In comparison to the metal-catalyzed versions, this is the only example under catalyst-free conditions via a non-carbene reaction pathway.
Electrophilic Etherification of α-Heteroaryl Carbanions with Monoperoxyacetals as a Route to Ketene O, O- And N, O-Acetals
Paris, Timothy J.,Schwartz, Chris,Willand-Charnley, Rachel
, p. 2369 - 2384 (2021/02/06)
Alkyl ketene acetals are useful reactants in a variety of synthetic processes, and yet, there are limited routes to their formation as isolable products. We now report the successful synthesis and isolation of heteroaryl ketene acetals through intermolecular transfer of alkoxyl (δ+OR) from electrophilic peroxides to lithiated benzofurans, indoles, and pyridines. Primary and secondary peroxyacetals enable selective transfer of the nonanomeric alkoxy group in moderate to high yield; substrates bearing an electron-donating substituent show enhanced reactivity toward electrophilic oxygen. Heteroaryl ketene acetals are remarkably stable throughout traditional purification techniques; the superior stability of ketene N,O-acetals compared to ketene O,O-acetals is presumably due to increased aromaticity of the indole and pyridine structures. The presented method overcomes typical problems associated with alkyl ketene acetal synthesis as reported products withstood workup and flash column chromatography procedures.
Reaction of 2-chloro-1-alkyl-1H-indole-3-carbaldehydes with barbituric acids and 5-methyl-2-phenyl-2,4-dihydropyrazol-3-one. Formation of compound with extremely short intramolecular hydrogen bond in eight-membered pseudocycle
Suzdalev, Konstantin F.,Babakova, Maria N.,Kartsev, Victor G.,Krasnov, Konstantin A.
, p. 64 - 75 (2015/05/12)
New indolin-2-one derivatives, containing in its molecules eight-membered pseudo-cycle with unusually short intramolecular hydrogen bond in OHO-bridge have been synthesized by reaction of 2-chloro-1-alkyl-1H-indole-3-carbaldehyde with barbituric acids or 5-methyl-2-phenyl-2,4-dihydropyrazol-3-one. Under the action of amines they undergo fragmentation to 5-aminomethylenebarbituric acids or 4-aminomethylenepyrazolones and 1-alkyl-1,3-dihydroindol-2-ones.
Palladium-Catalyzed Inter- and Intramolecular α-Arylation of Amides. Application of Intramolecular Amide Arylation to the Synthesis of Oxindoles
Shaughnessy, Kevin H.,Hamann, Blake C.,Hartwig, John F.
, p. 6546 - 6553 (2007/10/03)
2A palladium-catalyzed α-arylation of amides is reported. Intermolecular arylation of N,N-dimethylamides and lactams occurs using aryl halides, silylamide base, and a palladium catalyst. Intramolecular arylation of N-(2-halophenyl)amides occurs using alkoxide base and a palladium catalyst. The palladium catalyst was formed in situ from Pd(dba)2 (dba = trans,trans-dibenzylidene acetone) and BINAP (2,2′-bis(diphenylphosphino)-1,1′-binaphthalene). Although the intermolecular arylation of amides is less general than that reported previously for ketones, unfunctionalized and electron-rich aryl halides gave α-arylamides in 48-75% yield and N-methyl-α-phenylpyrrolidinone in 49% yield. These reactions provided the highest yields yet reported for regioselective amide arylations. Intramolecular amide arylation of 2-bromoanilides gave oxindoles in 52-82% yield. Mono- and disubstituted acetanilides gave 1,3-di- and 1,3,3-trisubstituted oxindoles. The use of dioxane, rather than THF, solvent was important for some of the amide arylations.
Selective photo-reduction of 1-alkylisatins in degassed alcoholic solutions
Tatsugi, Jiro,Ikuma, Kenji,Izawa, Yasuji
, p. 7 - 10 (2007/10/02)
Irradiation of 1-alkylisatins (1) in degassed alcohols afforded 1-alkyl-3-hydroxyoxindoles (2) and 1-alkyloxindoles (3) as chemoselective photoproducts.
Tandem Radical Translocation and Homolytic Aromatic Substitution: a Convenient and Efficient Route to Oxindoles
Beckwith, Athelstan L. J.,Storey, John M. D.
, p. 977 - 978 (2007/10/02)
Suitable o-bromo-N-methylanilides are efficiently converted into oxindoles by treatment with tributylstannane at 160 degC via tandem translocation of the initially formed aryl radical and intramolecular homolytic substitution.
A New and Practical Synthesis of Indolones
Boivin, Jean,Yousfi, Mohammed,Zard, Samir Z.
, p. 9553 - 9556 (2007/10/02)
A variety of indolones can be obtained from α-haloanilides through a radical cyclisation mediated by a combination of nickel powder and acetic acid.
Photoinduced Cyclizations of Mono- and Dianions of N-Acyl-o-chloroanilines and N-Acyl-o-chlorobenzylamines as General Methods for the Synthesis of Oxindoles and 1,4-Dihydro-3(2H)-isoquinolinones
Goehring, R. Richard,Sachdeva, Yesh P.,Pisipati, Jyothi S.,Sleevi, Mark C.,Wolfe, James F.
, p. 435 - 443 (2007/10/02)
Formation of the monoanions of a series of N-acyl-N-alkyl-o-chloroanilines by means of LDA in THF followed by irradiation with near-UV light affords 1,3-dialkyloxindoles in good yields.Similar photoinduced cyclizations of dianions derived from N-acyl-o-chloroanilines leads to 3-alkyloxindoles.Photocyclizations of mono- and dianion prepared from α,β-unsaturated o-haloanilides proceed to form 3-alkylideneoxindoles.Carbanions derived from N-acyl-o-chlorobenzylamines also undergo photoassisted ring closure to afford 1,4-dihydro-3(2H)-isoquinolinones.The influence of near-UV light and the effect of inhibitors implicate a radical-chain mechanism as the major reaction pathway in this convenient new method for oxindole and isoquinolinone synthesis.
SPECTROSCOPIC PROPERTIES OF VIOLACEIN AND RELATED COMPOUNDS: CRYSTAL STRUCTURE OF TETRAMETHYLVIOLACEIN
Laatsch, Hartmut,Thomson, Ronald H.,Cox, Philip J.
, p. 1331 - 1340 (2007/10/02)
Violacein and deoxyviolacein have been isolated from cultures of Alteromonas Luteoviolacea.The violacein-type lactams (1) and lactones (3) have a merocyanine chromophore which was confirmed by the effects of substituents on the visible spectra and by HMO calculations.Using parameters derived from an X-ray crystal structure analysis of tetramethylviolacein, PPP calculations of the electronic spectra of violacein and isoviolacein derivatives showed good agreement with observed values.
SELECTIVITY IN CYCLOADDITIONS-IX CYCLOADDITIONS OF NITRILE OXIDES TO INDOLES. REACTIVITY AND REGIOCHEMISTRY
Caramella, P,Corsico, A. Coda,Corsaro, A,Del Monte, D.,Albini, F. Marinone
, p. 173 - 182 (2007/10/02)
Cycloadditions of benzonitrile oxide and mesitonitrile oxide to N-methylindole and indole yield the acid sensitive cycloadducts 1 a-d with high regioselectivity.With N-carbethoxyindole the stable cycloadducts 1 e,f and minor amounts of the regioisomeric 2 e,f are isolated.The electron withdrawing substituent reduces both the regioselectivity and the reactivity of the cycloadditions.Frontier orbital considerations, based on MINDO/3 calculations, allow elucidation of the observed changes in reactivity and regiochemistry.
