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Search for "alkene" in Full Text gives 532 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization

  • Miao Xiao,
  • Liuyang Pu,
  • Qiaoli Shang,
  • Lei Zhu and
  • Jun Huang

Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152

Graphical Abstract
  • used as a powerful method for synthesizing complex natural products [20][21]. We envisaged that the A-ring in 4 could be constructed from the alkene-substituted β-keto ester precursor A via a bioinspired oxidative radical cyclization (Scheme 1D). Herein, we report the full details of our efforts to
  • connection of C8 and C12 in compound 21 could be realized through a photoredox-catalyzed radical cyclization of unactivated alkene-substituted β-ketoester 27. This reaction was expected to involve a 5-exo-trig radical cyclization via transition state TS-3 [38], in which the diastereoselectivity could be
  • proposed mechanism to 21 involved the formation of an electron-deficient, resonance-stabilized radical species, followed by intramolecular alkylation of the unactivated alkene to generate radical 29 via a diastereoselective 5-exo-trig cyclization step. Radical intermediate 29 was trapped by 2,4,6
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Published 24 Sep 2025

Photoswitches beyond azobenzene: a beginner’s guide

  • Michela Marcon,
  • Christoph Haag and
  • Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

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  • reaction can also be used to prepare precursors for the Ullman–Goldberg coupling (Scheme 12B and 12C); however, in the presence of halogens, an alternative reduction pathway of the alkene with tosylhydrazine and NaOAc must be used [55]. Hetereodiazocines 35b and 35c are synthesised by coupling of o
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Published 08 Sep 2025

Fe-catalyzed efficient synthesis of 2,4- and 4-substituted quinolines via C(sp2)–C(sp2) bond scission of styrenes

  • Prafull A. Jagtap,
  • Manish M. Petkar,
  • Vaishnavi R. Sawant and
  • Bhalchandra M. Bhanage

Beilstein J. Org. Chem. 2025, 21, 1799–1807, doi:10.3762/bjoc.21.142

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  • the FeIII species. An alternative mechanism involving a concerted [4 + 2] cycloaddition between the aza-butadiene moiety in II and the alkene, leading to intermediate IV, cannot be ruled out. Conclusion In summary, we have successfully developed a highly efficient method for the oxidative C–C bond
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Published 05 Sep 2025

Influence of the cation in hypophosphite-mediated catalyst-free reductive amination

  • Natalia Lebedeva,
  • Fedor Kliuev,
  • Olesya Zvereva,
  • Klim Biriukov,
  • Evgeniya Podyacheva,
  • Maria Godovikova,
  • Oleg I. Afanasyev and
  • Denis Chusov

Beilstein J. Org. Chem. 2025, 21, 1661–1670, doi:10.3762/bjoc.21.130

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  • an important role in medicinal and pharmaceutical chemistry [23][24][25] (Scheme 1a). Sodium hypophosphite exhibited good chemoselectivity – it selectively reduced imines while leaving other functional groups intact, e.g., nitro (NO₂), cyano (CN), alkene (C=C), and benzyloxy (OBn) groups. In contrast
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Published 20 Aug 2025

Catalytic asymmetric reactions of isocyanides for constructing non-central chirality

  • Jia-Yu Liao

Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129

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  • reaction between alkene 43 and 2,2′-dienone 44. The corresponding spirooxindole 45 was obtained in >19:1 dr, 63% yield, and 89% ee. Dynamic kinetic resolution of configurationally labile bridged biaryls The catalytic asymmetric dynamic kinetic resolution (DKR) of configurationally labile bridged biaryls
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Published 19 Aug 2025

Transition-state aromaticity and its relationship with reactivity in pericyclic reactions

  • Israel Fernández

Beilstein J. Org. Chem. 2025, 21, 1613–1626, doi:10.3762/bjoc.21.125

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  • resembles the trends found for Diels–Alder reactions discussed above. For the parent Alder–ene reaction, which involves an alkene as the enophile, we previously reported that the corresponding six-membered transition state can be considered as in-plane aromatic in view of its highly negative NICS(3, +1
  • the destabilizing 4-electron interaction with the C–C double bond of the alkene partner, dramatically reducing the barrier of the process. Other non-catalyzed pericyclic reactions Double group transfer reactions Double group transfer reactions (DGTRs) are a particular type of pericyclic reaction
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Published 12 Aug 2025

General method for the synthesis of enaminones via photocatalysis

  • Paula Pérez-Ramos,
  • Raquel G. Soengas and
  • Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

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  • -bromochromones via a Michael reaction of an amine with an electron-deficient alkene moiety and subsequent photocatalyzed debromination. With this dual catalytic system, a range of structurally diverse enaminone derivatives have been achieved in good yields with total trans selectivity. Mechanistic studies
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Published 29 Jul 2025

Wittig reaction of cyclobisbiphenylenecarbonyl

  • Taito Moribe,
  • Junichiro Hirano,
  • Hideaki Takano,
  • Hiroshi Shinokubo and
  • Norihito Fukui

Beilstein J. Org. Chem. 2025, 21, 1454–1461, doi:10.3762/bjoc.21.107

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  • formation between carbonyl and alkene units. Keywords: bathtub; chirality; cyclobisbiphenylenecarbonyl; figure-eight; Wittig reaction; Introduction Figure-eight π-conjugated molecules represent chiral macrocycles with a twisted crossover structure [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15
  • conformation (Sa,Sa)-A is feasible with a small activation barrier of 9.9 kcal mol−1. The figure-eight conformer (M,M)-B untwists to adopt an achiral conformation C with the exo-alkene units rotated inwards in opposite directions. These conformational changes are almost identical to those of CBBC 1. However
  • conditions. Mono-olefin 3 undergoes a reductive carbon–carbon-bond formation between carbonyl and alkene units upon treatment with TiCl4. The current study demonstrates that the transformation of the carbonyl groups of CBBC results in products with altered physical and chemical properties which may be
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Published 14 Jul 2025

Oxetanes: formation, reactivity and total syntheses of natural products

  • Peter Gabko,
  • Martin Kalník and
  • Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

Graphical Abstract
  • of the resulting alkene [36]. In addition, this intramolecular etherification corresponds to the 4-exo-tet cyclisation which, in terms of kinetics, is the least favoured n-exo-tet cyclisation mode where n ≤ 7 [37]. Nevertheless, the Williamson etherification still remains one of the most common
  • /RPC mechanism starts with a single-electron oxidation of the cobalt catalyst followed by a reaction with the siloxane to generate a cobalt–hydride complex. Subsequent hydride transfer to the alkene produces radical pair 23 which collapses to alkylcobalt intermediate 24. Another single-electron
  • butyraldehyde in a mercury vapour illuminator and since then, the reaction has become known as the Paternò–Büchi reaction. Throughout the years after the report, investigations in this field were focused on identifying new reactive alkene and carbonyl components, developing photosensitisers that would allow
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Published 27 Jun 2025

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

  • Jiangfei Chen,
  • Yi-Lin Qu,
  • Ming Yuan,
  • Xiang-Mei Wu,
  • Heng-Pei Jiang,
  • Ying Fu and
  • Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

Graphical Abstract
  • subsequently adds to the activated alkene of N-arylacrylamide, followed by intramolecular cyclization, ultimately leading to the formation of the hydroxy-containing oxindole via the loss of a hydrogen radical. In 2016, Han and colleagues developed a novel methodology in which TBHP served dual roles as both
  • to generate t-BuO and OH radicals. The t-BuO radical then abstracts a hydrogen atom from the β,γ-unsaturated ketoxime, forming the iminoxyl radical 10. This is followed by a 5-exo-trig cyclization, yielding a C-centered radical 11, which then adds to the alkene moiety of the N-arylacrylamide, forming
  • from N-cyanamide alkenes (Scheme 27) [16]. This approach is notable for its alignment with the principles of green chemistry, utilizing the metal-free photocatalyst 4CzIPN under visible light conditions. In this system, N-cyanamide alkene 54 and BrCF2CO2Et 55 were used as model substrates, with 4CzIPN
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Published 24 Jun 2025

Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates

  • Alexander S. Budnikov,
  • Igor B. Krylov,
  • Fedor K. Monin,
  • Valentina M. Merkulova,
  • Alexey I. Ilovaisky,
  • Liu Yan,
  • Bing Yu and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96

Graphical Abstract
  • various synthetically useful transformations, including alkene synthesis via Horner–Wadsworth–Emmons reaction [14][15], heterocycle construction [16][17], and the synthesis of chiral β-amino and β-hydroxy phosphonic acids [18][19]. Furthermore, they exhibit metal-complexing abilities [20], and anti
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Published 20 Jun 2025

Synthetic approach to borrelidin fragments: focus on key intermediates

  • Yudhi Dwi Kurniawan,
  • Zetryana Puteri Tachrim,
  • Teni Ernawati,
  • Faris Hermawan,
  • Ima Nurasiyah and
  • Muhammad Alfin Sulmantara

Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91

Graphical Abstract
  • stereoselectivity. The authors emphasized that, as the alkene moiety in 54 was in a terminal position, the stereoselectivity of the products was determined solely by the chiral environment of the catalysts. The application of this method to construct the C3–C11 fragment 60 of borrelidin is summarized in Scheme 8
  • compound 84 through a series of sequential steps, including chemoenzymatic (ω-1)-hydroxylation, regioselective dehydration of the resulting alcohol to form a terminal alkene, ozonolysis of the alkene to yield an aldehyde, reduction of the aldehyde product to a primary alcohol, and protection of the alcohol
  • subsequently dehydrated using Martin’s sulfurane to produce terminal alkene 90 in 97% yield. A sequence of ozonolysis, reduction with sodium borohydride, and PMB protection using camphorsulfonic acid and PMB-trichloroacetimidate reagents followed, yielding compound 87 in 62% yield. Next, the ester
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Published 12 Jun 2025

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

  • Chun-Yu Mi,
  • Jia-Yuan Zhai and
  • Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

Graphical Abstract
  • first report by Stork in the 1950s [1][2][3]. Compared with enols, enamines benefit from the lone pair of electrons on the nitrogen atom, which enhances the nucleophilicity of the alkene, enabling it to react with a broad range of electrophiles. This activation mode of carbonyl compounds has been so
  • , the terminal alkene remains intact during this process, and the initial protonation proceeds with full stereocontrol, rendering this transformation both highly chemo- and diastereoselective. From the cyclization result, it is presumed that the higher nucleophilicity of the alkyne functionality over
  • the terminal alkene and the conformational strain of forming a bridge[3.2.1]bicycle might be responsible for a selective 6-exo-trig cyclization. From tricyclic compound 4, anti-Markovnikov oxidation catalyzed by palladium led to the formation of aldehyde 5. When treated with p-TsOH, the intramolecular
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Published 22 May 2025

Harnessing tethered nitreniums for diastereoselective amino-sulfonoxylation of alkenes

  • Shyam Sathyamoorthi,
  • Appasaheb K. Nirpal,
  • Dnyaneshwar A. Gorve and
  • Steven P. Kelley

Beilstein J. Org. Chem. 2025, 21, 947–954, doi:10.3762/bjoc.21.78

Graphical Abstract
  • Abstract We present the first examples of alkene amino-sulfonoxylation reactions that leverage the unique reactivity of carbamate tethered N-alkoxy nitrenium ions. In almost all cases examined, the reactions deliver product with exquisite regioselectivity and diastereoselectivity. The protocols followed
  • are operationally very simple and only use commercial I(III) reagents and sulfonic acids, amounting to a metal-free protocol for alkene amino-oxygenation. No special precautions need be taken to exclude air or ambient moisture, and the products are amenable to further transformations. Keywords
  • : alkene; amino-sulfonoxylation; metal-free; tethered nitrenium; Introduction Our laboratory has a programmatic focus on the development of metal-free oxidation reactions that avoid the use of toxic reagents such as osmium and chromium [1][2][3]. In line with this agenda, we recently explored a mild amino
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Published 19 May 2025

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

  • Zhiyang Zhang,
  • Jialei Hu,
  • Hanfeng Ding,
  • Li Zhang and
  • Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

Graphical Abstract
  • at C10 was then introduced via a Michael addition (MeMgBr, CuI) to afford 22 in a yield of 65% (4:1 dr at C10). Initial attempts on the carbonyl 1,2-transposition protocol reported by Dong and co-workers were ineffective [45], leading to premature hydride termination and the formation of alkene 23
  • . As an alternative solution, by treating 22 with KHMDS and PhNTf2, enol triflation took place successfully. The resultant triflate was coupled with n-Bu3SnH to afford Δ1,29-alkene 23 in 83% yield over two steps. Subsequent hydroboration–oxidation by employing BH3·THF proceeded smoothly, providing a
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Published 12 May 2025

Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines

  • Muhammad Hasan,
  • Anatoly A. Peshkov,
  • Syed Anis Ali Shah,
  • Andrey Belyaev,
  • Chang-Keun Lim,
  • Shunyi Wang and
  • Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74

Graphical Abstract
  • scaffolds (Scheme 6) [64][65]. First, we attempted heterogeneous hydrogenation of the alkene functionality in compound 16a under 1 atm hydrogen pressure using Pd/C as a catalyst. Although the reaction proved sluggish, we were able to drive it to completion over a prolonged reaction time of 14 days
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Published 08 May 2025

Recent advances in controllable/divergent synthesis

  • Jilei Cao,
  • Leiyang Bai and
  • Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

Graphical Abstract
  • , the Shu group developed a catalyst-controlled regioselective and enantioselective hydroamination reaction of electron-deficient alkenes (Scheme 7) [30]. By efficiently regulating the regioselectivity and enantioselectivity of alkene 23 hydrometallation through catalytic systems, they overcame the
  • C(sp3)–C(sp3) coupling via distal stereocontrol, efficiently producing C3-alkylated pyrrolidines, while the nickel catalytic system afforded C2-alkylated pyrrolidines through a tandem alkene isomerization/hydroalkylation process. This method utilized readily accessible catalysts, chiral BOX ligands
  • insertion to achieve C3 selectivity, whereas nickel catalysis involved alkene isomerization to generate a (2,3-dihydropyrrolyl) intermediate Int-35, followed by C2-selective coupling. In 2024, the Zheng group reported a catalyst-controlled cyclization reaction of bicyclo[1.1.0]butanes (BCBs) 32 with α
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Published 07 May 2025

Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

  • Lewis McGhie,
  • Hannah M. Kortman,
  • Jenna Rumpf,
  • Peter H. Seeberger and
  • John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

Graphical Abstract
  • energy sensitizers, would represent an attractive platform for future reaction design. Here, we disclose the photoactivation of simple alkenylboronic esters established using alkene scrambling as a rapid reaction probe to identify a suitable catalyst and boron motif. Cyclic voltammetry, UV–vis analysis
  • facilitated landmark organic transformations, such as the venerable Paternò–Büchi [6][7][8], Norrish–Yang [9][10][11], and enone–alkene cycloadditions [12][13][14], that proceed via the generation of a singlet or triplet diradical through the activation of an unsaturated bond [2][14]. While these seminal
  • contributions have enabled the efficient activation of carbonyl and alkene moieties, the inability of most organic molecules to efficiently absorb photons at longer wavelengths often preclude their use in direct excitation strategies, requiring unique experimental set ups and light sources that are
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Published 30 Apr 2025

Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers

  • Seeun Lim,
  • Teresa Kim and
  • Yunmi Lee

Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63

Graphical Abstract
  • % yield under basic conditions using sodium hydroxide and tert-butanol. The reduction of nitrile 3q with lithium aluminum hydride generated amine 7 in an 85% yield, whereas the selective hydrogenation of the alkene moiety of 3q using a Pd/C catalyst in a H2 gas environment smoothly produced product 8 in a
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Published 17 Apr 2025

Origami with small molecules: exploiting the C–F bond as a conformational tool

  • Patrick Ryan,
  • Ramsha Iftikhar and
  • Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

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Published 02 Apr 2025

Recent advances in allylation of chiral secondary alkylcopper species

  • Minjae Kim,
  • Gwanggyun Kim,
  • Doyoon Kim,
  • Jun Hee Lee and
  • Seung Hwan Cho

Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51

Graphical Abstract
  • wide range of 1,1-diborylalkanes bearing an N-tosyl-protected amine as well as alkene and alkyne moieties underwent efficient coupling with allylic bromides. A notable advantage of this synthetic approach is that it provides a distinct alternative to traditional CuH-catalyzed allylic alkylation
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Published 20 Mar 2025

Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters

  • Olesja Koleda,
  • Janis Sadauskis,
  • Darja Antonenko,
  • Edvards Janis Treijs,
  • Raivis Davis Steberis and
  • Edgars Suna

Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50

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  • , the cyclization of the amino acid fragment-containing monoesters 9l,m afforded dipeptides 6l,m in 36% and 50% yield, respectively. Notably, the decarboxylative cyclization is compatible with the alkene moiety (product 6m). Both dipeptides 6l,m were obtained as a 67:33 mixture of diastereomers. In the
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Published 19 Mar 2025

Formaldehyde surrogates in multicomponent reactions

  • Cecilia I. Attorresi,
  • Javier A. Ramírez and
  • Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

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  • –Alder reaction between an imine and an alkene (Scheme 6). Very successfully, the multicomponent version of the Povarov reaction using aldehydes, anilines, and alkenes has been explored in a three-component cascade reaction to quinolines [28][29][30][31] (Scheme 6). Furthermore, protocols have been
  • developed in which the alkene compound has been replaced with other surrogates for electrophilic addition, such as ketones [32][33][34]. In the case of the carbonyl component, it is generally an aromatic aldehyde [30][33][34] and there are not many reports on using formaldehyde in the Povarov reaction. In a
  • the alkene moiety of the amine. The resulting stabilized carbocation 15 is then captured by formaldehyde (generated in situ from DMSO) leading to an intermediate oxocarbenium 16 that undergoes a cyclization to obtain the sulfenylated oxazinane derivative 13. In isotope labelling experiments using DMSO
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Published 13 Mar 2025

Cryptophycin unit B analogues

  • Thomas Schachtsiek,
  • Jona Voss,
  • Maren Hamsen,
  • Beate Neumann,
  • Hans-Georg Stammler and
  • Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

Graphical Abstract
  • containing a dimethylamino motif did not require an additional protecting group, ring closure was performed through alkene cross metathesis, which has been accomplished reliably and with good yields for other cryptophycins [11][26][27]. However, for the synthesis of a cryptophycin with a monomethylated amino
  • group in unit B a suitable protecting group, i.e., allyloxycarbonyl (Alloc), must be used. Since the presence of this allylic double bond would most likely interfere with a clean reaction outcome after alkene cross metathesis, we decided for a more classical ring-closure strategy through
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Published 07 Mar 2025

Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles

  • Yujun Pang,
  • Jinglan Yan,
  • Nawaf Al-Maharik,
  • Qian Zhang,
  • Zeguo Fang and
  • Dong Li

Beilstein J. Org. Chem. 2025, 21, 234–241, doi:10.3762/bjoc.21.15

Graphical Abstract
  • of our ongoing interest in radical cyclization reactions [22][23][24][25][26], we report here a sustainable and efficient protocol for synthesizing difluoromethylated and aryldifluoromethylated polycyclic imidazoles via visible-light-promoted cyclization of unactivated alkene-containing imidazoles
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Published 30 Jan 2025
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