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Search for "reaction mechanism" in Full Text gives 546 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

  • Olfa Mhasni,
  • Jalloul Bouajila and
  • Farhat Rezgui

Beilstein J. Org. Chem. 2023, 19, 1251–1258, doi:10.3762/bjoc.19.93

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  • elimination of imidazole (2a) finally providing the allylated derivative 6a (Scheme 2) [24][25][26][31]. It is notable, that such reaction mechanism involving the intermediate I was previously explored by Smith [32] and supported by studies of Tamura [33]. Next, in order to explore the scope of the above
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Published 01 Sep 2023

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

  • Ziying Xiao,
  • Fengshun Xu,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

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  • substituent. A plausible reaction mechanism is proposed to explain the formation of the different spirooxindoles. Keywords: cascade reaction; dimedone; isatin; 3-methyleneoxindole; multicomponent reaction; spirooxindole; Introduction Spirooxindole is one important privileged structural skeleton and is found
  • to explain the formation of different cyclic compounds, a plausible reaction mechanism was proposed in Scheme 2 on the basis of the present experiments and the previous works [51][52][53]. Firstly, 3-isatyl-1,4-dicarbonyl compound 1 was converted to a carbanion in the presence of base. In the
  • . This reaction provided efficient synthetic protocols for the synthesis of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] derivatives. A plausible reaction mechanism was proposed to explain the selective formation of the different polycyclic compounds
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Published 22 Aug 2023

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

  • Carlee A. Montgomery and
  • Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

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  • studies revealed that the C2–H bond of pyrrole did not participate in the rate-determining step. This led the authors to propose a multi-step reaction mechanism, where irradiation of an initial halogen-bonded EDA complex 47 led directly to iodocyclobutane 48 (Figure 10). Reductive elimination of
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Published 07 Aug 2023

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

  • Damiano Diprima,
  • Hannes Gemoets,
  • Stefano Bonciolini and
  • Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

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  • a study was conducted to explore possible additives that can further enhance the reaction rate (Figure 1) thus increasing the overall productivity. Also, analyzing the effect of the additives on the kinetics might give further clues for the extensive elucidation of the reaction mechanism. For a
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Published 31 Jul 2023

Photoredox catalysis harvesting multiple photon or electrochemical energies

  • Mattia Lepori,
  • Simon Schmid and
  • Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

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Published 28 Jul 2023

The unique reactivity of 5,6-unsubstituted 1,4-dihydropyridine in the Huisgen 1,4-diploar cycloaddition and formal [2 + 2] cycloaddition

  • Xiu-Yu Chen,
  • Hui Zheng,
  • Ying Han,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 982–990, doi:10.3762/bjoc.19.73

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  • -configured. For explaining the formation of the various cyclic compounds, a plausible reaction mechanism was proposed on the base of the previously reported works [41][42][43][44] and the present experiments (Scheme 2). Initially, the nucleophilic addition of isoquinoline to dimethyl acetylenedicarboxylate
  • -dihydropyridines. Plausible reaction mechanism for the various products 4, 5, and 6. Optimizing the reaction conditions.a Synthesis of isoquinolino[1,2-f][1,6]naphthyridines 4a–o.a Synthesis of the bicyclic compounds 5a–o and 6a–o.a Supporting Information The crystallographic data of compounds 4k (CCDC 2260340
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Published 29 Jun 2023

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

  • Dileep Kumar Singh and
  • Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

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  • nanoorganocatalysts. Various solvent systems, such as aqueous conditions, different organic solvents, solvent-free conditions, ionic liquids, and DESs, have been reported in modified Clauson–Kaas reactions at room temperature, under thermal and microwave-assisted conditions. In the Clauson–Kaas reaction mechanism
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Published 27 Jun 2023

Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine

  • Alessio Regni,
  • Francesca Bartoccini and
  • Giovanni Piersanti

Beilstein J. Org. Chem. 2023, 19, 918–927, doi:10.3762/bjoc.19.70

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  • different classes of ergot alkaloids. (b) and (c) Strategies for the photoredox-catalyzed radical decarboxylative cyclization cascade reaction of DMAT derivatives (this work). Proposed reaction mechanism for photoredox-catalyzed radical decarboxylative cyclization. Proposed reaction mechanism for photoredox
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Published 26 Jun 2023

Pyridine C(sp2)–H bond functionalization under transition-metal and rare earth metal catalysis

  • Haritha Sindhe,
  • Malladi Mounika Reddy,
  • Karthikeyan Rajkumar,
  • Akshay Kamble,
  • Amardeep Singh,
  • Anand Kumar and
  • Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

Graphical Abstract
  • styrenes 64 using a Ni–Al bimetallic system and NHC ligand 65 through intermolecular hydroarylation with high levels of enantio- and regioselectivity in the alkylated products 66 (Scheme 13). Also, the authors performed DFT studies revealing the reaction mechanism and supported that the interaction of the
  • plays a role as an activator and is subsequently eliminated via deoxygenative elimination furnishing the C-2-functionalized pyridines 167. The reaction mechanism (Scheme 32b) involves the initial C–H-cupration of 166 producing an oxazolyl–copper intermediate 168. Nucleophilic addition followed by C–H
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Published 12 Jun 2023

Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

  • Constantine V. Milyutin,
  • Andrey N. Komogortsev,
  • Boris V. Lichitsky,
  • Mikhail E. Minyaev and
  • Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

Graphical Abstract
  • developed for this reaction, allowing for the synthesis of pyrimidines 9 containing an allomaltol unit in good yields (Scheme 2). The process is of a general nature and is suitable for the synthesis of various target products 9 with electron-rich or deficient substituents. The plausible reaction mechanism
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Published 07 Jun 2023

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

  • Joydev K. Laha,
  • Pankaj Gupta and
  • Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

Graphical Abstract
  • single electron transfer (SET), is proposed to be involved in the plausible reaction mechanism. Keywords: arylsulfonylimine; benzylic oxidation; benzyl sulfonamide; K2S2O8; sulfate radical anion; Introduction Among various imine compounds [1], N-arylsulfonylimines are perhaps the most prominent due to
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Published 05 Jun 2023

Photocatalytic sequential C–H functionalization expediting acetoxymalonylation of imidazo heterocycles

  • Deepak Singh,
  • Shyamal Pramanik and
  • Soumitra Maity

Beilstein J. Org. Chem. 2023, 19, 666–673, doi:10.3762/bjoc.19.48

Graphical Abstract
  • reaction mechanism. Reaction optimization.a Supporting Information Supporting Information File 110: Experimental section and characterization of synthesized compounds. Funding Financial support from SERB (CRG/2021/004140), India, is gratefully acknowledged. D.S and S.P thank IIT(ISM) and CSIR, New Delhi
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Published 12 May 2023

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

  • Grédy Kiala Kinkutu,
  • Catherine Louis,
  • Myriam Roy,
  • Juliette Blanchard and
  • Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

Graphical Abstract
  • furfural derivatives by C–H activation, a) in batch: previous works, and b) in continuous flow: this work. C3-alkylation of bidentate imine 1 performed in batch. Optimization of the heating for the alkylation reaction on the homemade pulsed-flow setup. Proposed reaction mechanism for the alkylation
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Published 03 May 2023

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

  • Martina Mamone,
  • Giuseppe Gentile,
  • Jacopo Dosso,
  • Maurizio Prato and
  • Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

Graphical Abstract
  • desired product 3a in low chemical yield (entry 15, Table 1). On the other hand, 3a was obtained in moderate yield (60%) using methanol as solvent (entry 16, Table 1). To shed light on the reaction mechanism, the formation of an EDA complex between the α-iodosulfone 2a and DABCO was investigated using
  • absorption spectra recorded in acetonitrile in 1 cm path quartz cuvettes. [DABCO]: 0.5 M; [2a]: 0.5 M. 1H NMR titration of DABCO in a solution of 2a in ACN-d3 to detect their halogen-bonding association through the shift of the signal of Hα. Proposed reaction mechanism for the photochemical alkylation of 1a
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Published 27 Apr 2023

Access to cyclopropanes with geminal trifluoromethyl and difluoromethylphosphonate groups

  • Ita Hajdin,
  • Romana Pajkert,
  • Mira Keßler,
  • Jianlin Han,
  • Haibo Mei and
  • Gerd-Volker Röschenthaler

Beilstein J. Org. Chem. 2023, 19, 541–549, doi:10.3762/bjoc.19.39

Graphical Abstract
  • confirm the lack of selectivity during the cyclopropanation process with terminal alkenes, the reaction mechanism between the diazo reagent 5 and styrene as a model substrate in the presence of CuI catalyst was investigated by density functional theory (DFT) calculations (Table 2). In the first step, CuI
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Published 25 Apr 2023

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

  • Austin Pounder,
  • Eric Neufeld,
  • Peter Myler and
  • William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

Graphical Abstract
  • salicylaldehydes with EWGs failed to react. The authors hypothesized the reaction mechanism begins with the association of the Rh(III) catalyst with the hydroxy group of salicylaldehyde (151a) resulting in a selective cleavage of the aldehyde C–H bond producing the rhodocycle 153 which side-on coordinates with the
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Published 24 Apr 2023

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

  • Louis Monsigny,
  • Floriane Doche and
  • Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

Graphical Abstract
  • , respectively). Regarding the reaction mechanism, the active Co(III) complex G was obtained from the dimeric catalyst [Cp*CoI2]2 in the presence AgSCF3 and/or NaOPiv·H2O. Then, the reversible formation of the metallacycle H occurs, which after a ligand exchange in the presence of AgSCF3 leads to the formation
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Published 17 Apr 2023

Group 13 exchange and transborylation in catalysis

  • Dominic R. Willcox and
  • Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

Graphical Abstract
  • ]. Through a series of single-turnover experiments a reaction mechanism was proposed where H-B-9-BBN catalysed the dehydrocoupling of carboxylic acids 47 with HBpin through B‒O/B‒H transborylation, to give the acyloxy boronic ester 49. This underwent direct defluoronative carboxylation with the alkyl
  • -catalysed hydroboration of unsaturated compounds and the general reaction mechanism. a) Gallium-catalysed asymmetric hydroboration of ketones and the proposed mechanism. b) Gallium-catalysed hydroboration of CO2. c) Gallium-catalysed hydroboration of ketones and imines. Gallium(I)-catalysed allylation
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Published 21 Mar 2023

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

  • Tharun K. Kotammagari,
  • Sweta Misra,
  • Sayantan Paul,
  • Sunita Kunte,
  • Rajesh G. Gonnade,
  • Manas K. Santra and
  • Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

Graphical Abstract
  • dimerized product (±)-4. Proposed reaction mechanism for the formation of compound (±)-4 under TBAF-mediated Rauhut–Currier reaction. Synthesis of (±)-incarvilleatone (1) from RC dimerized product (±)-4. Separation of rac-incarvilleatone (1) and determination of absolute configurations of both the
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Published 21 Feb 2023

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

  • Bilge Banu Yagci,
  • Selin Ezgi Donmez,
  • Onur Şahin and
  • Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

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  • analysis of lactam 19l. In order to shed light on the details of the reaction mechanism, we have performed carefully designed mechanistic studies which consist of experiments on the effect of β-silicon stabilization, the alkene geometry of the α,β-unsaturated acyl chloride reactants, and adventitious water
  • and control experiments provided valuable insights on the reaction mechanism including the importance of the β-silicon effect and the alkene geometry of the α,β-unsaturated acyl chloride reactants on reactivity, different potential modes of cyclization, and the effect of adventitious water on the aza
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Published 17 Jan 2023

NaI/PPh3-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

  • Dan Liu,
  • Yue Zhao and
  • Frederic W. Patureau

Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5

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  • oxindole 3ap in 63% yield. In order to gain insight into the reaction mechanism, some control experiments were further performed. When a radical scavenger such as 2,2,6,6-tetramethyl-1-piperidinyloxyl (TEMPO) was added to the catalytic system under standard conditions, the reaction was fully inhibited, and
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Published 16 Jan 2023

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

  • Elena R. Lopat’eva,
  • Igor B. Krylov,
  • Dmitry A. Lapshin and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

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  • -diamines [111] (Scheme 21A). The proposed reaction mechanism suggests the generation of a triarylamine radical cation, which oxidizes the vinylarene by a SET mechanism. The resultant vinylarene cation radical X is attacked by the sulfamide nucleophile with Y formation. The second oxidative SET leads to the
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Published 09 Dec 2022

Navigating and expanding the roadmap of natural product genome mining tools

  • Friederike Biermann,
  • Sebastian L. Wenski and
  • Eric J. N. Helfrich

Beilstein J. Org. Chem. 2022, 18, 1656–1671, doi:10.3762/bjoc.18.178

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  • secondary metabolite biosynthetic enzymes are distant paralogs of enzymes involved in primary metabolism [63][71]. These NP biosynthetic enzymes are hypothesized to have undergone significant sequence and selectivity changes while still operating based on the same reaction mechanism (e.g., fatty acid
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Published 06 Dec 2022

Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone

  • Motoyuki Isoda,
  • Kazuyuki Sato,
  • Kenta Kameda,
  • Kana Wakabayashi,
  • Ryota Sato,
  • Hideki Minami,
  • Yukiko Karuo,
  • Atsushi Tarui,
  • Kentaro Kawai and
  • Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1642–1648, doi:10.3762/bjoc.18.176

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  • . Mechanistic investigation of the intramolecular cyclization The reaction mechanism of the intramolecular cyclization can only be speculative at this stage. We have already reported the generation of a rhodium hydride (Rh–H) complex from RhCl(PPh3)3 and Et2Zn, in which the reaction with tert-butyl acrylate
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Published 02 Dec 2022

One-pot double annulations to confer diastereoselective spirooxindolepyrrolothiazoles

  • Juan Lu,
  • Bin Yao,
  • Desheng Zhan,
  • Zhuo Sun,
  • Yun Ji and
  • Xiaofeng Zhang

Beilstein J. Org. Chem. 2022, 18, 1607–1616, doi:10.3762/bjoc.18.171

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  • different R1 was employed for the synthesis to give 7f with COMe in a trace amount and no product 7g with a Ph group. The following reactions with aliphatic aldehydes gave 7h and 7i as complex mixtures [54][55][56][57][58][59][71]. The reaction mechanism of the double annulations for sequential N,S
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Published 28 Nov 2022
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