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Search for "elimination" in Full Text gives 773 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Enhanced reactivity of Li+@C60 toward thermal [2 + 2] cycloaddition by encapsulated Li+ Lewis acid

  • Hiroshi Ueno,
  • Yu Yamazaki,
  • Hiroshi Okada,
  • Fuminori Misaizu,
  • Ken Kokubo and
  • Hidehiro Sakurai

Beilstein J. Org. Chem. 2024, 20, 653–660, doi:10.3762/bjoc.20.58

Graphical Abstract
  • , photoirradiation triggered the elimination of the addends, reforming the starting Li+@C60 (Figure 3). No other insoluble or undetectable products by HPLC were identified during the study. On the other hand, the reactions of 3 and 4 with Li+@C60 did not proceed significantly even under higher temperature reaction
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Published 25 Mar 2024

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

  • Nataliia V. Kirij,
  • Andrey A. Filatov,
  • Yurii L. Yagupolskii,
  • Sheng Peng and
  • Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

Graphical Abstract
  • compound, but led to the elimination of two fluorine atoms with the formation of 1,1,4,4-tetrafluorobuta-1,3-diene [9]. It was also shown that the reactions of the boron reagent (CAACMe)BH2Li(thf)3 with hydrofluoroolefins, including (Z)-1,1,1,4,4,4-hexafluorobut-2-ene, results in defluoroborylation to form
  • defluorosilylation product was obtained [11]. In a related study of the hydrosilylation reaction of olefins 1a,b, it was shown that, depending on the catalyst used, platinum or rhodium compounds, along with the products of the addition of silane to the double bond, the elimination of the fluorine atom occurs with
  • completion of the reaction the mixture of isomers 3a,b was separated from the water phase and distilled at 55 °C. Further increase in the amount of KOH led to the elimination of the second mole of HBr with the formation of hexafluorobut-2-yne (4). By controlling the course of the reaction by the 19F NMR
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Published 27 Feb 2024

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

  • Nahed Ketata,
  • Linhao Liu,
  • Ridha Ben Salem and
  • Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

Graphical Abstract
  • cycle involves the oxidative addition of 1,8-dibromonaphthalene. Then, a concerted metalation–deprotonation of the arene, which usually occurs at the ortho-position of an activating group such as a fluorine or a chlorine atom, followed by reductive elimination, gives the corresponding intermediate 1
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Published 23 Feb 2024

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

  • Periklis X. Kolagkis,
  • Eirini M. Galathri and
  • Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

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Published 22 Feb 2024

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

  • Carlos R. Azpilcueta-Nicolas and
  • Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

Graphical Abstract
  • intermediacy of free radicals, indicating the involvement of the SET pathway (Scheme 21C). Eventually, reductive elimination of 113 afforded product 114 while regenerating the catalytic species 109. It is worth nothing that further transformations of NHPI esters under photoinduced Cu catalysis have been
  • alkyl radical 12 is captured by intermediate 122, resulting in the formation of complex 123. At this point, the metal center has undergone a two-electron oxidation, making it well-suited for reductive elimination yielding the cross-coupling product 124. Under these catalytic conditions, various TM
  • -coupling product 127 is then formed via reductive elimination of 126 which gives NiI intermediate 128. At this stage, it is proposed that the NiI complex 128 can participate in a SET event with another equivalent of substrate 10, generating another equivalent of radical 12, that propagates into the next
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Published 21 Feb 2024

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

  • Aissam Okba,
  • Pablo Simón Marqués,
  • Kyohei Matsuo,
  • Naoki Aratani,
  • Hiroko Yamada,
  • Gwénaël Rapenne and
  • Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

Graphical Abstract
  • conversion in situ, triggered by thermal activation, photoirradiation or redox control. Beside well-established reactions involving the elimination of carbon-based small molecules, i.e., retro-Diels–Alder and decarbonylation processes, the late-stage extrusion of chalcogen fragments has emerged as a highly
  • ultimate elimination of chalcogen fragments upon thermal activation, photoirradiation and electron exchange. Keywords: arenes; chalcogens; extrusion; fused-ring systems; precursor approach; Introduction π-Conjugated polycyclic compounds (π-CPCs), including polycyclic aromatic hydrocarbons and their
  • or crystals, or adsorbed on metallic substrates [9][10][11][12]. Conversion of the non-planar soluble precursor into the flat π-conjugated target compound is triggered on demand by a stimulus such as thermal activation, irradiation with light or injection of electrons, leading to the elimination of
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Published 15 Feb 2024

Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C70 production

  • Cristina Castanyer,
  • Anna Pla-Quintana,
  • Anna Roglans,
  • Albert Artigas and
  • Miquel Solà

Beilstein J. Org. Chem. 2024, 20, 272–279, doi:10.3762/bjoc.20.28

Graphical Abstract
  • energy barrier (ΔΔG = 0.9 kcal·mol−1). The formation of intermediate α-INT 3 and β-INT 3 was found endergonic by 9.3 and 7.6 kcal·mol−1, respectively. Subsequently, both site isomers of INT 3 can undergo reductive elimination with barriers of 6.9 and 9.4 kcal·mol−1 to deliver the corresponding
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Published 13 Feb 2024

Catalytic multi-step domino and one-pot reactions

  • Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

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  • -aminopyrazoles with azlactones under solvent-free conditions, through subsequent elimination of a benzamide molecule in a superbasic medium, is described by the Fisyuk group [13]. A further facile one-pot process toward a new series of copper(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrin analogues is described
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Published 08 Feb 2024

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

  • Ekaterina V. Kolupaeva,
  • Narek A. Dzhangiryan,
  • Alexander F. Pozharskii,
  • Oleg P. Demidov and
  • Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

Graphical Abstract
  • pyridine rings, the naphthalene core at positions 5(8) and the CH2CH2 bridge (dehydrogenation) undergo chemical modifications under mild conditions, giving the corresponding acenaphthylenes. The latter can also be obtained in an unusual way by tele-elimination from 5,8-dibromodipyridoacenaphthene by
  • reaction with neutral or anionic bases. Keywords: dipyrido[3,2-e:2′,3′-h]acenaphthene (acenaphthylene); hydrogen bonding; π-stacking; substitution reactions; tele-elimination; Introduction Quinoline derivatives, classical nitrogen-containing heterocycles, are widely distributed in nature in various forms
  • make molecule 5 (and derivatives) more rigid and flat when compared to compound 3 but it will also affect its reactivity and the sites of functionalization. This work is devoted to the clarification of this circumstance with substitution and elimination reactions chosen as the key transformations. The
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Published 08 Feb 2024

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

  • Yumei Wang,
  • Guangzhu Wang,
  • Yanping Zhu and
  • Kaiwu Dong

Beilstein J. Org. Chem. 2024, 20, 205–211, doi:10.3762/bjoc.20.20

Graphical Abstract
  • (2p). However, when using 3,3-difluoro-2-(naphthalen-2-ylethynyl)-3H-indole or 3,3-difluoro-2-phenyl-3H-indole as the substrate, the generated indoles underwent fast HF elimination/aromatization and finally gave indole derivatives (2q and 2r) in almost quantitative yields. To examine the efficiency
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Published 01 Feb 2024

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

  • Amina Moutayakine and
  • Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

Graphical Abstract
  • careful review of the product structure it was revealed that the purported dibenzodiazepine products were, in fact, diarylimines, which resulted from a nucleophilic addition of the aniline reagents to the aldimine substrates, followed by elimination of an tosylamine product. This was one of the principle
  • (1a), followed by the oxygen-promoted insertion of the phenylboronic acid coupling partner 7 to deliver intermediate II that undergoes reductive elimination to give diarylamine 3a along with regeneration of the copper catalyst (Scheme 5). Then, a palladium-promoted oxidative addition of the C–Br bond
  • elimination of the palladium catalyst. Conclusion In summary, we have reported two one-pot pathways and two step-wise pathways to access dibenzodiazepinone (DBDAP) derivatives via copper-catalyzed Chan–Lam amination/carbonylative cyclization and Buchwald–Hartwig amination/carbonylative cyclization and their
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Published 31 Jan 2024

Comparison of glycosyl donors: a supramer approach

  • Anna V. Orlova,
  • Nelly N. Malysheva,
  • Maria V. Panova,
  • Nikita M. Podvalnyy,
  • Michael G. Medvedev and
  • Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

Graphical Abstract
  • competing elimination from a sialyl donor is the main reason for diminished yields in sialylation” as described previously [37]. Due to possible lability of O-trifluoroacetyl groups, the crude product was treated with MeONa in MeOH in order to remove all O-acyl groups and then with Ac2O in Py to install O
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Published 31 Jan 2024

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

  • Viktoria A. Ikonnikova,
  • Cristina Cheibas,
  • Oscar Gayraud,
  • Alexandra E. Bosnidou,
  • Nicolas Casaretto,
  • Gilles Frison and
  • Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

Graphical Abstract
  • reaction is possible upon elimination of the resulting benzylic alcohol on D, allowing another arylation forming E [18]. This complex sequence of transformations is herein applied to the synthesis of 1-aryltetralines, analogues of cyclolignan natural products having important medicinal applications [19][20
  • methide intermediate 9 upon elimination of the hydroxy group. This highly electrophilic species could trigger a second intramolecular Friedel–Crafts reaction leading to 6. The cyclic connectivity of 6 was determined by bidimensional NMR experiments, incidentally showing a broadening of the signals of
  • % yields. The success of the reaction with an ester substituent to give 12k is surprising if we compare it with other electron-withdrawing groups like CN or NO2, which failed to give the corresponding cyclization products 12l–n (not shown). Instead, olefin products 13l–n arising from an elimination were
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Published 25 Jan 2024
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  • intermediate. Subsequently, following the production of an oxide ion through the ring-opening reaction of the 2,5-dihydrofuran ring, the oxide ion attacks another TCNEO molecule. This sequence culminates in the elimination of the tetracyanodioxetane moiety (either as dioxetane or carbonyl dicyanide molecules
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Published 22 Jan 2024

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF3: the case of alkyne hydration. Chemistry vs electrochemistry

  • Marta David,
  • Elisa Galli,
  • Richard C. D. Brown,
  • Marta Feroci,
  • Fabrizio Vetica and
  • Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

Graphical Abstract
  • of IL). The reference DIPEA/BMIm-BF4 or DBU/BMIm-BF4 solutions were prepared by mixing 0.1 mmol of the appropriate base with 0.5 mL of BMim-BF4. Recycling of ILs The IL sample already used was recycled after the elimination of diethyl ether and water, by keeping the IL under vacuum (7 mbar) under
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Published 28 Dec 2023

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

  • Xing Liu,
  • Wenjing Shi,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

Graphical Abstract
  • and proceeds through a by base-promoted annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates. The reaction mechanism of this formal [4 + 3] annulation includes the in situ generated allylic ylide, nucleophilic substitution, Michael additon, and elimination processes
  • depicted in Scheme 5. At first, MBH carbonates of isatin 2 is attacked at the α-position by the Lewis base to give the ammonium salt A with elimination of carbon dioxide and a tert-butoxide ion. Secondly, the ammonium salt A is deprotonated by the in situ generated tert-butoxide ion to give the allylic
  • elimination of a proton and the Lewis base. Obviously, the spiro compounds 5 and 7 are formed by a similar reaction mechanism. Additionally, the method was applied to a gram-scale reaction of α-halogenated p-toluenesulfonylhydrazone 6c and MBH nitrile of isatin 2c under the standard conditions (Scheme 6). The
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Published 18 Dec 2023

Substituent-controlled construction of A4B2-hexaphyrins and A3B-porphyrins: a mechanistic evaluation

  • Seda Cinar,
  • Dilek Isik Tasgin and
  • Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

Graphical Abstract
  •  1). In our previous works, we have shown that the reaction of pyrrole with N-tosylimines leads to pyrrole sulfonamides as the main products [35]. In another work, in the synthesis of dipyrromethane structures, we have proven the formation of azafulvene intermediates by Cu(OTf)2-appended elimination
  • of sulfonamide groups from pyrrolic sulfonamides [36]. Here in this work, during the reaction at 0 °C, intermediates I–VI were detected (Figure 1). The primary intermediates II and IV are formed by the addition of tripyrrane 1 to tosylimine 2d. Further elimination of N-tosyl group(s) from these
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Published 06 Dec 2023

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

  • Tinglan Liu,
  • Yu Zhou,
  • Junhong Tang and
  • Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

Graphical Abstract
  • radical and I· played a pivotal as an intermediate step in the production of alkyl iodides B. Compound B could undergo a further elimination reaction to yield various olefins 11. Regarding benzyl substrates, the radical I· demonstrated its efficacy as a reagent for hydrogen atom transfer (HAT
  • facilitated by the process of photoexcited radical decarboxylation. On the other hand, the copper catalytic cycle involved the capture of alkyl radicals by the copper complex B, the activation of heteroatom-containing substrates 30 by a base-mediated proton transfer, and the subsequent reductive elimination
  • process. This reductive elimination led to the formation of C(sp3)–X (X = O or N) cross-coupling products 31. Cyclization Radical-involved selective C–H functionalizations [25][26], particularly annulation reactions [26], have emerged as highly effective and powerful techniques in synthesis, possessing
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Published 22 Nov 2023

Tying a knot between crown ethers and porphyrins

  • Maksym Matviyishyn and
  • Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

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  • elimination reactions between in situ generated 16-K2–19-K2 and MCl3(THF)3 yielding 16-Ti, 18a-Ti (structure not shown), 16-V (Scheme 7), 18a-V (structure not shown), and 19-Cr [67]. The Ti(III)-incorporated 16-Ti and 18a-Ti exhibited paramagnetic properties; their identity was confirmed through elemental
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Published 27 Oct 2023

Radical chemistry in polymer science: an overview and recent advances

  • Zixiao Wang,
  • Feichen Cui,
  • Yang Sui and
  • Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

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  • addition. The termination step occurs by either disproportionation (radical β-elimination, Equation 4) or biradical coupling (Equation 5). Chain transfer (Equations 6–8) is usually considered as a type of side effect in radical polymerization [18]. It occurs between the growing chain and a transfer agent
  • corresponding alkoxyamine is very low and it tends to undergo β-elimination in acrylic systems. Thus, TEMPO is only suitable for the polymerization of styrenic monomers at a high temperature and for long time [36]. Functionalized TEMPO was therefore developed for the polymerization of other monomers, such as
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Published 18 Oct 2023

Lewis acid-promoted direct synthesis of isoxazole derivatives

  • Dengxu Qiu,
  • Chenhui Jiang,
  • Pan Gao and
  • Yu Yuan

Beilstein J. Org. Chem. 2023, 19, 1562–1567, doi:10.3762/bjoc.19.113

Graphical Abstract
  • complexed with the starting material 2a to generate intermediate B and HONO [22]. Then, the intermediate B conjugates with HONO to generate intermediate C [22]. Next, the intermediate D is produced by the same progress. The intermediate D then undergoes elimination of nitroxylic acid to produce nitrile
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Published 16 Oct 2023

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

  • Tzu-Yu Huang,
  • Mario Djugovski,
  • Sweta Adhikari,
  • Destinee L. Manning and
  • Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

Graphical Abstract
  • gem-difluoroalkenes with organic azides in morpholine as a solvent to construct fully decorated morpholine-substituted 1,2,3-triazoles. Mechanistic studies revealed the formation of an addition–elimination intermediate of morpholine and gem-difluoroalkenes prior to the triazolization reaction via two
  • cycloaddition or addition–elimination reactions with 1,3-dipoles and gem-difluoroalkenes is largely unexplored and the only report of a cycloaddition is with 2-fluoroindolizines (Figure 1A) via a β-fluoride elimination in an SNV (nucleophilic vinylic substitution)-like transformation [9]. Nucleophilic addition
  • -trisubstituted-1,2,3-triazoles, with a pendant morpholine at the C-4 position are formed with complete regiocontrol via β-fluoride elimination in an SNV-like transformation (Figure 1C). 1,2,3-Triazoles are a privileged scaffold in medicinal chemistry with a myriad of pharmacological activities against cancer [11
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Published 05 Oct 2023

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

  • Jessica Villegas,
  • Bryce C. Ball,
  • Katelyn M. Shouse,
  • Caleb W. VanArragon,
  • Ashley N. Wasserman,
  • Hannah E. Bhakta,
  • Allen G. Oliver,
  • Danielle A. Orozco-Nunnelly and
  • Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

Graphical Abstract
  • synthesis began with the generation of substituted 2-bromo-1-aminonaphthalenes 9 and 10 (Scheme 6). After α-bromination of tetralones 1 and 2, intermediates 3 and 4 underwent elimination/aromatization with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to afford 2-bromo-1-naphthols 5 and 6 in fairly good yield
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Published 29 Sep 2023

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

  • Fatemeh Doraghi,
  • Seyedeh Pegah Aledavoud,
  • Mehdi Ghanbarlou,
  • Bagher Larijani and
  • Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

Graphical Abstract
  • intermediate III. Reductive elimination of Pd from III gave product 5 and species IV. Finaly, Pd(II) species were reproduced by ligand exchange to restart the next cycle (Scheme 4). In 2014, Fu and co-workers described a facile method for the C–H thiolation of phenols 7 with 1-(substituted phenylthio
  • activated the N–S bond in II, which reacted with I to obtain IV, followed by C–S reductive elimination to give the thiolated product 30 or 31. On the other hand, the interaction of I with Cu(OAc)2 activated the N–S bond in III to afford IV, which was subjected to C–N reductive elimination to deliver the
  • reductive elimination to yield ketone 78. In the acylthiolation cycle, the azaphilic ZnCl2 activated NTSE 1’’’ via N–Zn coordination to facilitate the leaving ability of succinimide. Then, nucleophilic substitution of arylmagnesium bromide 75 to intermediate IV provided thioester 79. In 2022, Gao and co
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Published 27 Sep 2023

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

  • Angel Palillero-Cisneros,
  • Paola G. Gordillo-Guerra,
  • Fernando García-Alvarez,
  • Olivier Jackowski,
  • Franck Ferreira,
  • Fabrice Chemla,
  • Joel L. Terán and
  • Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

Graphical Abstract
  • . Trapping of this enolate would lead to β-amino acid units, a class of compounds that has attracted a great deal of attention [19][20][21][22][23][24]. An obvious possible shortcoming that had to be considered was still that the generated zinc enolate III having a β-amino group could undergo β-elimination
  • informative. As discussed previously (Scheme 4), application of the developed protocol for 1,4-addition to 10 only yields N-benzyl-N-tert-butylsulfinamide following β-elimination. By contrast, in the presence of benzaldehyde, 1,4-addition–aldol condensation is predominant, yielding 26 in 56% yield as a 49:25
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Published 21 Sep 2023
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