A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• derivative and an estrone derivative. Mechanistically, the process begins with the coordination of a chiral rhodium-based catalyst to the 2-acylimidazole substrate. Deprotonation by the base 2,6-lutidine activates the substrate for anodic oxidation by raising the level of the highest occupied molecular

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• reversible coordination of BINOLs 13 or 21 to the prenyl- or geranylboronic acids 14, favouring one of the four possible chair-like transition states. The reaction scope for indoles 15 was demonstrated on a limited set of 5-methoxyindole, 5-bromoindole, and 4-indolyl-pinacol boronates reacting with E- and Z

• between COBI 72 and coordinated COBI–imine complex 74 as 1 to 4.6. Despite the low accuracy of this estimate, it is clear that both species 72 and 74 are present, and that coordination is reversible under the reaction conditions. The formation of the COBI–imine complex was further evidenced by comparing

• by a nucleophile, is energetically favoured over pathway via 77, in which the imine is activated directly by coordination to the Lewis acidic boron atom of the free imine complex. This supports the mechanism proposed in the original study based on the NMR experiments. In 2021, Jacobsen and co-workers

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• catalysts or photochemical procedures have been developed to enable this transformation [7][8][9]. The reactivity of hypervalent iodine reagents can be enhanced via Lewis acid catalysis [10]. For example, PIDA becomes a stronger oxidant upon coordination of BF3·OEt2, enabling chemistry that was not

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

• when describing coordination compounds as commonly found in transition metal catalysis for example [57]. Another kind of representation that has found considerable application for ML in organocatalysis, is the use of descriptors. These are sets of numerical or categorical values to encode a molecule. A

Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

• Andrey R. Galeev,
• Maksim V. Dmitriev,
• Alexander S. Novikov and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

• (Figure 1). On the other hand, 3,5-diarylanilines can be regarded as meta-terphenyls which are of great interest for material and coordination chemistry [5][6][7][8][9][10][11][12][13][14][15][16]. Moreover, compounds with diverse bioactivities and natural products contain the meta-terphenyl moiety as a

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• coordination of the magnesium ions and subsequent hydrazine inactivation. The diversity-oriented nature of this consecutive four-component synthesis was used to synthesize 17 different donor/acceptor-substituted pyrazoles 108 in moderate to good yields (Scheme 39) [136]. The synthesis of bispyrazoles was also

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• similar to 6. They observed high N1-selectivity using NaH in THF with pentyl bromide and electron-deficient indazoles, postulating a coordination of the indazole N2-atom and an electron-rich oxygen atom in a C-3 substituent with the Na+ cation from NaH. Under anhydrous conditions the yields ranged from 44

• system (Figure 10). Under conditions A, deprotonation and cesium coordination were heavily favored by 11.1 kcal/mol (18(N-H)). Transition states 18-N2-Cs and 18-N1-Cs were found leading to N1- and N2-products, respectively. NCIs between the cesium cation with the ester and sulfonate oxygens, and

• support the claim made by Alam and Keeting that a tight ion pair drives N1-selectivity when electron-withdrawing groups that can coordinate the cation are present at the 3-position. When 3-cyanoindazole is employed and no bidentate coordination is possible with N2, the nucleophilicity of N1 drives the

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• inert atmosphere and oxidizing 64 in the presence of CoBr2 (Scheme 24, conditions c and d; one-pot: 10–43%, two steps: 11–37% yields). Interestingly, polycycles 69 were formed when I2 was employed as the oxidant (Scheme 24, conditions e), which was presumably due to the coordination between the oxidant

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• coordination of the triflate to two positions of the iodane. Thermal ellipsoids are displayed with 50% probability. Selected bond lengths and angles: I1–N1: 2.44(4) Å; I1–O1: 1.94(9) Å; I1–O2: 3.04(1) Å; C1–I1–N1: 73.5(8)°; O1–I1–N1: 166.6(5)°; N1–I1–C1–O1: 177.8(3)°. 1H NMR spectra of the time-dependent

Divergent role of PIDA and PIFA in the AlX₃ (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study

• Kevin A. Juárez-Ornelas,
• Manuel Solís-Hernández,
• Pedro Navarro-Santos,
• J. Oscar C. Jiménez-Halla and
• César R. Solorio-Alvarado

Beilstein J. Org. Chem. 2024, 20, 1580–1589, doi:10.3762/bjoc.20.141

• –AlCl2 complex yields the final product 1-chloro-2-naphthol (P–Cl). The calculated mechanism for the chlorination reaction starts with coordination of a PIFA oxygen atom to aluminum chloride. This generates a highly exergonic PIFA–AlCl3 adduct. In Figure 1, the Gibbs free energy of this adduct is set as

• stoichiometry or the formation of PhICl2 as chlorinating species, were also investigated and ruled out. Thus, for the chlorination of 2-naphthol with the PIFA/AlCl3, 1:1 system, we found that in general, once the intermediate I-1–Cl is formed, the following coordination of 2-naphthol with the TFAO ligand via

• reaction proceeds through a stepwise mechanism. Thus, the reaction starts with the coordination of aluminum bromide to an acetate ligand in PIDA to form the PIDA–AlBr3 adduct in a highly exergonic process. Similar to the previous section, the Gibbs free energy at this point was set as 0 kcal/mol for

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• vacant coordination site. By installing a cleavable directing group, the authors were able to extend the scope reported by Sanford and co-workers outside of 8-aminoquinoline substrates. Multiple electron-donating and withdrawing groups on the ring were tolerated, including the pinacolborane group

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• has a tetrameric structure, displays a high affinity for ᴅ-galactose (ᴅ-Gal, with Kd = 34 μM) and galactosides. The 3- and 4-hydroxy function on the ᴅ-Gal unit are involved in the coordination of Ca2+ in the binding site [5][6][7][8][32]. A large range of galactosyl conjugates have been synthetized

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

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

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

• carbon atom of isocyanide has both a lone electron pair and empty orbitals, so it has outstanding electrophilic and nucleophilic reactivity. At the same time, isocyanide also has good coordination ability to coordinate with metals to form diverse metal complexes [1][2][3]. Therefore, isocyanides have

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• transformation of the aryl glyoxals is outlined below (Scheme 4), which depicts the coordination of the hemiacetal B with the metal catalyst to give C, followed by hydride transfer to form the metal-coordinated Cannizzaro product D. Another intramolecular asymmetric Cannizzaro reaction was reported by Wu et al

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• complexation, a significant red-shift of the dipyrrin band to 465 nm was observed due to the metal coordination with the dipyrrin moieties in 4b. To compare the structures of 1a and 1b, they are calculated through geometry optimization with the density functional theory (DFT) method. The alkyl chains at the

Introduction of peripheral nitrogen atoms to cyclo-meta-phenylenes

• Koki Ikemoto and
• Hiroyuki Isobe

Beilstein J. Org. Chem. 2024, 20, 1207–1212, doi:10.3762/bjoc.20.103

• equilibrium. These results show that the coordination chemistry associated with nitrogen dopants may well be controlled by the locations and directions of the nitrogen atoms. Conclusion Macrocycles with nitrogen atoms doped at the periphery were designed and synthesised, and their electronic properties were

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• methanolysis, the hemiaminal ether product 3 is formed. We hypothesize that the enantioselectivity-determining step consists of the migratory insertion of the aryl group bonded to palladium to the pyrroline. The steric effect of the t-Bu group favors the coordination of the pyrroline with the protecting group

Three-component N-alkenylation of azoles with alkynes and iodine(III) electrophile: synthesis of multisubstituted N-vinylazoles

• Jun Kikuchi,
• Roi Nakajima and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2024, 20, 891–897, doi:10.3762/bjoc.20.79

• ). Observing no byproducts originating from phenylacetylene, we speculate that the lack of reactivity stems from the relatively low electron density of the terminal alkyne, which likely leads to direct coordination of pyrazole to the iodine(III) reagent. To probe the relative reactivity of different azoles

• attributed to its much greater Lewis basicity compared to other azoles, likely killing the reactivity of the iodine(III) electrophile by direct coordination. The present reaction could be performed on a preparative scale. Thus, 1 mmol-scale synthesis of the vinylazoles 4aa and 4ba could be successfully

New variochelins from soil-isolated Variovorax sp. H002

• Jabal Rahmat Haedar,
• Aya Yoshimura and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63

• structure – a linear hexapeptide with β-hydroxyaspartate and hydroxamate functional groups, serving in iron-binding coordination. Three new variochelins C–E (3–5) were characterized by varied fatty acyl groups at their N-termini; notably, 4 and 5 represent the first variochelins with N-terminal unsaturated

Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• explained by the sterical demand of the aldehyde (R = t-Bu), leading to suppressing its coordination with the complex. The ee values achieved with the complex of ligand Ia were variable (29–83%), whereas better enantioselectivity was found for less reactive aldehydes (aliphatic and bearing electron-donating

• -enantiomer. A possible explanation of these results is illustrated in Figure 2, which shows plausible transition structures for the Henry reaction. Due to the Jahn–Teller effect, i.e., distortion of the octahedral Cu(II) complex forming four equatorial and two perpendicular coordination sites [18], the

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• first part will be devoted to chemically responsive tweezers, including stimuli such as pH, metal coordination, and anion binding. Then, redox-active and photochemical tweezers will be presented. Keywords: coordination; molecular recognition; molecular switches; photoswitch; redox; supramolecular

• , influence magnetic interactions, or serve as multilevel switches. These new directions will be highlighted in the following. Review Coordination-responsive tweezers Coordination-responsive switchable systems hold great potential thanks to the tunability and dynamic nature of the coordination bond. This is

• direction since the beginning of the 21st century concomitantly with the growth of the field [11][18]. Because of their ability to respond to chemical stimuli, coordination-responsive switchable tweezers have the potential to be used in many applications including but not limited to supramolecular sensors

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• substrate is the most active. In 2012, Kojima and Mikami utilized bimetallic tropos BIPHEP [bis(phosphino)biphenyl]–digold complexes for enantioselective intramolecular hydroamination of N-alkenylureas [9], and they hypothesized that N-alkenylureas could be activated through bimetallic coordination not only

• with alkene but also the urea carbonyl. The Bronsted acidity of the urea would be increased by coordination to gold, and if such coordination is key to enabling reactivity, this would confirm the higher reactivity of urea 1a. The divergent behavior of sulfonamide 1d does not find an easy explanation

• -centered while being C-centered in analogous anions alpha to sulfonamides [51]. Sulfonamides are known to protonate at nitrogen [31]. Gold coordination to carbonyls would be predicted to retain N-centered nucleophilicity, while gold coordination to the sulfonamide nitrogen would not. Sulfonamides are less

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

• radical cation species 89 and the radical anion 90 with the corresponding charges balanced by the LiBF4 additive. Notably, it was suggested that LiBF4 could also facilitate the reduction of the NHPI ester substrate, potentially by the coordination of Li cation to the phthalimide moiety. Next

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• with a carbohydrate here. It is found in a shallow groove, supporting our data on the lack of a distinct distal binding specificity. We report a tight coordination of the O3 and O4 hydroxy groups of the galactose residue involving Asp21, Asn43, and Gln41 side chains, as well as the Gly24 main chain

• coordination with the Trp36 ring nitrogen (alpha anomer) or the Gly24 main chain oxygen (beta anomer). Conclusion Our work presents a substantial exploration of the binding specificity and mechanism of the hitherto uncharacterized lectin CMA1 from melons. The binding specificity of CMA1, C2-substituted

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

• of quinoquinolines, their planar structure, and very easy coordination to acidic and electrophilic sites (including water [15][22] or the C–H bond of chloroform [11]) almost always lead to co-crystallization. For example, there is no such crystallographic information for quinoquinoline 3 itself. In