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

• tetrachlorophthalimide (TCPhth) active esters towards C(sp3)–N cross-couplings with nitrogen heterocycles (Scheme 27). The catalytic reaction was proposed to begin by oxidative addition of RAE 104 to catalyst Bi-1, forming an in cage radical pair consisting of BiII species 130 and α-amino radical 107 (Scheme 27B

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• carry out the catalytic reaction homogeneously. The solubility of the lipophilic catalyst 2 was investigated in ten solvents with low polarity, including a new, bio-based polar aprotic solvent, MeSesamol [33]. The catalyst’s precipitation – which is necessary for its recycling – was tested by adding a

Radical ligand transfer: a general strategy for radical functionalization

• David T. Nemoto Jr,
• Kang-Jie Bian,
• Shih-Chieh Kao and
• Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

• functionalization via the canonical organometallic steps of oxidative addition/reductive elimination was ruled out via catalytic reaction of the macrocyclic Groves-type porphyrin catalyst V, a species that is unable to accommodate the mutual cis-orientation of ligands for metal-centered reductive elimination. The

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

• Arisu Koyanagi,
• Yuki Murata,
• Shiori Hayakawa,
• Mio Matsumura and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

• thioamide. Further investigations to expand the cyclodesulfurization reaction to other substrates and the development of a catalytic reaction using bismuth reagent are in progress, and the results will be reported in due course. Experimental General procedure for the synthesis of 2-arylazoles A mixture of

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

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

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• ''-indoline] 8a as the major product. The loading of tri(n-butyl)phosphine played an important role for the formation of the products. When 2.0 equiv of P(n-Bu)3 were used, the reaction gave the spiro compound 8a in 71% yield. Thus, this reaction is not a simple catalytic reaction and tri(n-butyl)phosphine

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• reactivity and selectivity because the cage provides a second coordination sphere around the catalyst thus controlling the catalytic reaction. This idea has been impressively demonstrated by Reek [69], Ballester [70], and Raymond [71], where a single gold-based catalytic unit is encapsulated inside a

• trans-styrylboronic acid (43, Figure 10). The catalytic reaction inside the chiral cavity of (S)-40 provided a yield up to 91% with a very high enantioselectivity (94% ee). In contrast, the larger chiral macrocycle (S)-41 afforded a slightly lower catalytic activity (87%), however, at a similar

• functionality. For instance, a particular catalytic reaction can be efficiently carried out by choosing a specific functionality. The functional entity responsible for catalysis can either be incorporated with the building blocks, or the catalyst itself may be encapsulated into the cavity. Unfortunately, the

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

• and activation ability. Catalytic reaction optimization The synthesized macrocycles were then applied as catalysts in the decarboxylative addition of malonic acid half thioesters (MAHTs) to isatin-derived ketimines [48]. The reaction between ketimine 6a and MAHT 7a was initially performed in THF at

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• photochemical catalytic reaction in aqueous medium. In addition, our group [30] reported the construction of a supramolecular photocatalytic system with a two-step FRET process through the supramolecular assembly of water-soluble pillar[5]arene and TPE derivatives as donor and EsY and Nile Red (NiR) as

• FRET process, whilst the m-TPEWP5G-EsY nanorod assembly could act as a nanoreactor providing a suitable environment for the photochemical catalytic reaction in aqueous solution under visible light irradiation. In the presence of 0.5 mol % m-TPEWP5G-EY in aqueous solution, 2-bromo-1-phenylethanone (1a

Diametric calix[6]arene-based phosphine gold(I) cavitands

• Gabriele Giovanardi,
• Andrea Secchi,
• Arturo Arduini and
• Gianpiero Cera

Beilstein J. Org. Chem. 2022, 18, 190–196, doi:10.3762/bjoc.18.21

• that the catalytically active gold(I) nuclei are too far to be influenced by the cavity or by the macrocycle itself. Finally, the catalytic reaction was attempted using C’(AuCl). We thus observed a selectivity towards product 2a (1.5:1) which might be caused by the different orientation of the

Enantioselective PCCP Brønsted acid-catalyzed aminalization of aldehydes

• Martin Kamlar,
• Robert Reiberger,
• Martin Nigríni,
• Ivana Císařová and
• Jan Veselý

Beilstein J. Org. Chem. 2021, 17, 2433–2440, doi:10.3762/bjoc.17.160

• example, when benzaldehydes substituted with fluorine or chlorine in the para-position were employed in catalytic reaction with anthranilamide (1a), the corresponding derivatives 3i,j were isolated in 58 and 69% yield, respectively. The rates of enantioselectivity for both reactions were lower and

Base-free enantioselective S_N2 alkylation of 2-oxindoles via bifunctional phase-transfer catalysis

• Mili Litvajova,
• Emiliano Sorrentino,
• Brendan Twamley and
• Stephen J. Connon

Beilstein J. Org. Chem. 2021, 17, 2287–2294, doi:10.3762/bjoc.17.146

• catalytic reaction exhibited poor enantioselectivity and none of the catalysts employed were able to promote the reaction with product ee higher than 22% (Scheme 1C – for more details see Supporting Information File 1). Over the last decade, Maruoka and co-workers discovered that phase-transfer-catalysed

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• efficient HAT photocatalyst to perform the desired C–H abstraction (Scheme 10) [62]. The catalytic reaction required near-ultraviolet light irradiation (Kessil 34 W 390 nm LEDs) and the exclusion of both oxygen and water to the success of the reaction. A variety of cyclic, acyclic, and bicyclic aliphatic

• arylated with moderate to good yields. When both primary and secondary C(sp3)‒H bonds are present in the substrate, regioselectivity favors the secondary position. The catalytic reaction conditions were compatible with the C(sp3)‒H arylation of tetrahydrothiophene (28a) as well [68]. The enantioselective C

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• role of the photochemical macrocyclic-host-assisted catalytic reaction of different guests as well as hybrid materials in energy transfer were summarized. Moreover, the mechanisms of these supramolecular systems during the photochemical reactions were also highlighted. Due to the inherent limiting

Selective and reversible 1,3-dipolar cycloaddition of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with 1,3-diphenylprop-2-en-1-ones under microwave irradiation

• Alexander P. Molchanov,
• Mariia M. Efremova,
• Mariya A. Kryukova and
• Mikhail A. Kuznetsov

Beilstein J. Org. Chem. 2020, 16, 2679–2686, doi:10.3762/bjoc.16.218

• earlier that the electronic properties of the substituted aryl group of diaziridines and chalcones showed a profound influence on the yields of a catalytic reaction (scandium triflate with a chiral ligand); when a phenyl or p-chloro/methylphenyl-substituted diaziridine was employed, the cycloaddition

Regioselective cobalt(II)-catalyzed [2 + 3] cycloaddition reaction of fluoroalkylated alkynes with 2-formylphenylboronic acids: easy access to 2-fluoroalkylated indenols

• Tatsuya Kumon,
• Miroku Shimada,
• Jianyan Wu,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 2193–2200, doi:10.3762/bjoc.16.184

• corresponding trimer of the fluoroalkylated alkyne, as reported by our group [27]. Finally, only 2-iodoaryl ketones (R3 = Me, Cy, Ph) were applicable in this catalytic reaction, whereas the cycloaddition using 2-iodobenzaldehyde (R3 = H) did not work at all. Therefore, the development of practical protocols for

Stereoselective Biginelli-like reaction catalyzed by a chiral phosphoric acid bearing two hydroxy groups

• Xiaoyun Hu,
• Jianxin Guo,
• Cui Wang,
• Rui Zhang and
• Victor Borovkov

Beilstein J. Org. Chem. 2020, 16, 1875–1880, doi:10.3762/bjoc.16.155

• asymmetric Biginelli reaction of unsubstituted and electron-rich aromatic aldehydes [17]. To further expand the application of this type of chiral phosphoric acids, the asymmetric Biginelli-like catalytic reaction was examined. Firstly, coupling of benzaldehyde (4a), cyclohexanone, and N-benzylthiourea was

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• silico based design of possible GlfT2 inhibitors that mimic the TS structure. The galactofuranosyltransferase GlfT2 is a bisubstrate enzyme with a single catalytic domain and its catalytic reaction transition state shares some structural similarities with the previously modeled N

• development of the drugs against tuberculosis. Despite that the studied structures do not contain the galacto configuration on the furanose ring, the studied compounds mimic the TS structure of the GlfT2 catalytic reaction. The TS structure mimetics are stable compounds designed to mimic the unstable TS

• proposed structures nicely follow the probable TS structure of the GlfT2 catalytic reaction as is shown in Supporting Information File 1, Figure S2. The available GlfT2 X-ray structure contains only the UDP part of the native UDP-Galf donor substrate (PDB ID: 4FIY). The structure of the UDP-Galf was docked

Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

• Zhenghui Liu,
• Peng Wang,
• Zhenzhong Yan,
• Suqing Chen,
• Dongkun Yu,
• Xinhui Zhao and
• Tiancheng Mu

Beilstein J. Org. Chem. 2020, 16, 645–656, doi:10.3762/bjoc.16.61

• , the appropriate amount of Et3N was set at 1.2 mmol. Effect of solvents Solvents act as the reaction media and strongly influence the catalytic reactions [52][53]. We screened nine representative solvents in the catalytic reaction and the results are summarized in Figure 1c. Apparently, protic solvents

Aerobic synthesis of N-sulfonylamidines mediated by N-heterocyclic carbene copper(I) catalysts

• Faïma Lazreg,
• Marie Vasseur,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2020, 16, 482–491, doi:10.3762/bjoc.16.43

• reaction between 6 and 8. Synthesis of copper-acetylide intermediate A via [Cu(Cl)(Triaz)]. Catalytic reaction involving copper-acetylide complex A. Catalyst and solvent optimisation.a,b Supporting Information Supporting Information File 139: Experimental and characterisation data. Supporting Information

Synthesis of six-membered silacycles by borane-catalyzed double sila-Friedel–Crafts reaction

• Yafang Dong,
• Masahiko Sakai,
• Kazuto Fuji,
• Kohei Sekine and
• Yoichiro Kuninobu

Beilstein J. Org. Chem. 2020, 16, 409–414, doi:10.3762/bjoc.16.39

• in terms of the functional group tolerance and versatility of these previously reported synthetic methods due to the use of a stoichiometric amount of the organolithium reagents. In addition, despite these contributions, catalytic reaction systems have not been developed as much [26][27]. The sila

• benzosiloles [39]. We have also contributed to the synthesis of silafluorenes from biphenyls and dihydrosilanes using a borane-catalyzed double sila-Friedel–Crafts reaction [40][41]. Subsequently, we envisaged that the catalytic reaction between diaryl ethers and dihydrosilanes may be a useful protocol to

Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors

• Man-Man Wang,
• Hao Huang,
• Lei Shu,
• Jian-Min Liu,
• Jian-Qiu Zhang,
• Yi-Le Yan and
• Da-Yong Zhang

Beilstein J. Org. Chem. 2020, 16, 233–247, doi:10.3762/bjoc.16.25

• dark blue sphere. The commonly recognized HPPD catalytic reaction mechanism. Synthetic route of the title compounds I. Reagents and conditions: (a) methyl chloroacetate, K2CO3, CH3CN, 65 °C; (b) K2CO3, H2O, 65 °C; (c) aqueous HCl solution (10%), rt; (d) substituted 1,3-cyclohexanediones, EDCI, DMAP

Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

• Gerardo M. Ojeda,
• Prabhat Ranjan,
• Pavel Fedoseev,
• Lisandra Amable,
• Upendra K. Sharma,
• Daniel G. Rivera and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 2447–2457, doi:10.3762/bjoc.15.237

• rhodium catalyst to promote C(sp2)–H activation in the presence of a suitable directing group. The Ugi-azide reaction provides broad molecular diversity and enables the introduction of the tetrazole moiety, which may further assist the catalytic reaction by coordinating the metal center. The scope of the

• tetrazole ring takes part in the catalytic reaction mechanism by chelating Rh(III) upon activation of the amide ortho-position. This work illustrates the synthetic potential of combining isocyanide-based multicomponent reactions with metal-catalyzed transformations to generate structural diversity and

Naphthalene diimides with improved solubility for visible light photoredox catalysis

• Barbara Reiß and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 2043–2051, doi:10.3762/bjoc.15.201

• catalytic activity was representatively tested by the MacMillan benchmark reaction [53]. For this type of photoredox catalytic reaction, solubility of cNDIs in DMF is a crucial prerequisite. Results and Discussion Synthesis of cNDIs 2–6 and their solubility The commercially available precursor for all NDIs

• %. The emission of this LED overlays well with the absorbance of cNDI 6 (Figure 2). As expected, the photoredox catalytic reaction with cNDI 6 is much “cleaner” than with NDI 1 and the substrate conversion differs only slightly from the product yield. Taken together, cNDI 6 is a suitable visible light

• evaluated for the MacMillan benchmark reaction. This photoredox catalytic reaction in the presence of cNDI 6 was much “cleaner” than with NDI 1 since the conversions differed only slightly from the product yields. Irradiations were performed with LEDs in the visible light range between 520 nm and 640 nm

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Synthesis of non-racemic 4-nitro-2-sulfonylbutan-1-ones via Ni(II)-catalyzed asymmetric Michael reaction of β-ketosulfones

• Alexander N. Reznikov,
• Anastasiya E. Sibiryakova,
• Marat R. Baimuratov,
• Eugene V. Golovin,
• Victor B. Rybakov and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2019, 15, 1289–1297, doi:10.3762/bjoc.15.127

• , and, on the other hand, the ratio of diastereomers in the presence of the same catalyst strongly depends on the solvent used. This suggests that the dr is determined by the rates ratio of the catalytic reaction (which can occur with high or low diastereoselectivity) and the epimerization of products