875-30-9Relevant academic research and scientific papers
A photolabile 'traceless' linker for solid-phase organic synthesis
Horton,Stamp,Routledge
, p. 9181 - 9184 (2000)
A photolabile linker based on a thiohydroxamic acid has been shown to be efficient 'traceless' linker, revealing an aliphatic CH bond on photolysis at 350 nm. Methods for the synthesis, loading and phtolytic cleavage of the linker are described. (C) 2000 Elsevier Science Ltd.
Preparation method of nitrogen-alkyl (deuterated alkyl) aromatic heterocycle and alkyl (deuterated alkyl) aryl ether compound
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Paragraph 0048-0050, (2021/04/03)
The invention provides a method for preparing nitrogen-alkyl(deuterated alkyl)aromatic heterocycle and alkyl(deuterated alkyl)aryl ether compounds. The method adopted in the invention specifically comprises the following steps: firstly, adding an alkoxy base (MOR') or a combination reagent Q (comprising a base M'X, an alcohol C and a molecular sieve E) into a solvent B to be stirred; then, addingan aromatic compound D of nitrogen sulfonyl or oxygen sulfonyl into a mixture; separating and purifying after reaction to obtain nitrogen-alkyl(deuterated alkyl)aromatic heterocycle or alkyl(deuterated alkyl)aryl ether. The method can realize one-step conversion from an electron withdrawing benzenesulfonyl protecting group on a nitrogen or oxygen atom to an electron donating alkyl protecting group, avoids using highly toxic alkyl halide, and has advantages of being efficient, economical, environmentally friendly, mild in condition, good in substrate universality and high in yield; the prepareddeuterated compounds can be widely applied to the fields of pharmaceutical chemistry and organic chemistry synthesis.
Synthesis of 3-halogenated 2,3′-biindoles by a copper-mediated 2,3-difunctionalization of indoles
Gu, Xiaoting,Liang, Taoyuan,Wei, Wanxing,Zhang, Xiaoxiang,Zhang, Yingying,Zhang, Zhuan
supporting information, p. 10403 - 10407 (2021/12/17)
A copper-mediated 2,3-difunctionalization of indoles to afford 3-halogenated 2,3′-biindoles is described herein. The protocol uses readily available feedstocks and a naturally abundant copper catalyst system, which allows the regioselective formation of C-C and C-X (X = Cl & Br) bonds in one single operation. Here the copper metal salt serves not only as a catalyst but also as a reactant to provide the source of halogen. This operationally simple procedure avoids the utilization of environmentally unfriendly reagents and displays good functional group compatibility. Noteworthily, the introduction of halogen into molecules would offer great potential for further chemical transformations. This journal is
Electrochemical Umpolung C-H Functionalization of Oxindoles
Maulide, Nuno,Pastor, Miryam,Vayer, Marie,Weinstabl, Harald
supporting information, (2022/01/12)
Herein, we present a general electrochemical method to access unsymmetrical 3,3-disubstituted oxindoles by direct C-H functionalization where the oxindole fragment behaves as an electrophile. This Umpolung approach does not rely on stoichiometric oxidants and proceeds under mild, environmentally benign conditions. Importantly, it enables the functionalization of these scaffolds through C-O, and by extension to C-C or even C-N bond formation.
Tandem C-H Transformations by a Single Iridium Catalyst: Direct Access to Indoles and Indolines from o-Alkyl-N-methylanilines
Ohmura, Toshimichi,Yagi, Kaito,Kusaka, Satoshi,Suginome, Michinori
, p. 3152 - 3157 (2020/03/04)
In the presence of an iridium catalyst bearing DTBM-SEGPHOS as a ligand and tert-butylethylene as a hydrogen scavenger, 2-ethyl-N-methylanilines were converted directly to 3-methylindoles in high yields. The reaction proceeded efficiently in mesitylene at 150 °C through transfer dehydrogenation of the ethyl group and following intramolecular dehydrogenative C-H/C-H coupling of the N-methyl group with the vinyl group formed in situ. The iridium catalyst system was applied to the asymmetric conversion affording enantioenriched indolines bearing a quaternary stereogenic carbon center at the C3 position.
Reductive aromatization of oxindoles to 3-substituted indoles
Mandal, Tirtha,Chakraborti, Gargi,Dash, Jyotirmayee
supporting information, (2020/06/21)
A practical and scalable approach for the synthesis of 3-substituted indoles is delineated via hydride nucleophilic addition to 3-substituted-2-oxindoles. The reaction proceeds through reductive aromatization involving indolinium ion intermediate. A wide range of 3-functionalized indoles have been synthesized. The method is employed for the synthesis of 3,3?-bis-indoles and a dimeric 3-indole derivative. Moreover, this protocol is used to obtain naturally occuring amino acid tryptamine.
Metal and Oxidant Free Construction of Substituted- and/or Polycyclic Indoles: A Useful Alternative to Bischler and Related Syntheses
De Crescentini, Lucia,Favi, Gianfranco,Mantellini, Fabio,Mari, Giacomo,Santeusanio, Stefania
, (2020/08/27)
A wide range of substituted indoles or polycyclic derivatives containing the indole core are easily accessible by acidic treatment of aromatic amines and 1,2-diaza-1,3-dienes. Unlike the related indole-Bischler synthesis, the regioselectivity of the method here reported is unique and predictable, the yields are generally good and also electron withdrawing substituted indoles are smoothly recovered.
A rhodium(ii) catalysed domino synthesis of azepino fused diindoles from isatin tethered: N -sulfonyl-1,2,3-triazoles and indoles
Kahar, Nilesh,Jadhav, Pankaj,Reddy, R. V. Ramana,Dawande, Sudam
supporting information, p. 1207 - 1210 (2020/02/04)
An efficient and convenient protocol for the synthesis of a novel class of azepino fused diindoles from isatin tethered N-sulfonyl-1,2,3-triazoles and indoles has been disclosed. The reaction proceeds via denitrogenative aza-vinyl rhodium carbene formation to give a carbonyl ylide, which with indole results in 1,3-dipolar cycloaddition followed by sequential semipinacol rearrangement/ring expansion/oxidation to produce azepino fused diindoles. The reaction shows a broad substrate scope giving up to 81% yield. Furthermore, reversible catalytic hydrogenation and photophysical studies were carried out to demonstrate the application of these molecules.
Solid-State Radical C?H Trifluoromethylation Reactions Using Ball Milling and Piezoelectric Materials
Ito, Hajime,Kubota, Koji,Lee, Joo Won,Pang, Yadong
supporting information, p. 22570 - 22576 (2020/10/21)
The application of piezoelectricity for the generation of trifluoromethyl (CF3) radicals is reported together with the development of a method for the mechanochemical C?H trifluoromethylation of aromatic compounds. As compared to conventional solution-based approaches, this mechanoredox C?H trifluoromethylation enables cleaner and more sustainable access to a wide range of trifluoromethylated N-heterocycles and peptides, which are important structural motifs in modern drug discovery. This study thus represents an important milestone for future applications of mechanoredox systems to medicinal and pharmaceutical science.
Tethered Counterion-Directed Catalysis: Merging the Chiral Ion-Pairing and Bifunctional Ligand Strategies in Enantioselective Gold(I) Catalysis
Frison, Gilles,Guinchard, Xavier,Marinetti, Angela,Retailleau, Pascal,Smal, Vitalii,Voituriez, Arnaud,Zhang, Zhenhao
supporting information, p. 3797 - 3805 (2020/03/10)
Tethering a metal complex to its phosphate counterion via a phosphine ligand enables a new strategy in asymmetric counteranion-directed catalysis (ACDC). A straightforward, scalable synthetic route gives access to the gold(I) complex of a phosphine displaying a chiral phosphoric acid function. The complex generates a catalytically active species with an unprecedented intramolecular relationship between the cationic Au(I) center and the phosphate counterion. The benefits of tethering the two functions of the catalyst are demonstrated here in a tandem cycloisomerization/nucleophilic addition reaction, by attaining high enantioselectivity levels (up to 97% ee) at an unusually low 0.2 mol % catalyst loading. Remarkably, the method is also compatible with a silver-free protocol.
