N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• pyrazole derivatives (including indazole), benzimidazole, 1,2,3-triazole, indole, carbazole, indoline, quinazoline, and isoquinoline. Nevertheless, many heterocyclic motifs still remain beyond the attention of researchers. For example, glutarimides that incorporate tetrazole and 1,2,4-triazole substituents

• acknowledged to be effective in introducing substituents to the nitrogen atoms of NH-heterocycles by means of carbene insertion into the N–H bond upon catalytic or photolytic decomposition of diazo compounds [25]. Furthermore, the reaction of N-heterocycles containing multiple non-equivalent nitrogen atoms

• also highly regioselective, proceeding via attack on the 2-N atom to give products 6m–o. In the instance of unsubstituted benzotriazole, a minor regioisomer 6m' was identified with a calculated yield of 6% using NMR data. Benzotriazoles featuring electron-withdrawing substituents showed incomplete

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

• -substituted N-tosylimine and 5,10-bis(pentafluorophenyl)tripyrromethane formed A6-hexaphyrin as the main product along with the inevitable formation of side products, A4-porphyrin and higher expanded porphyrins [28]. meso-Phenyloligopyrroles having electron-rich substituents at the 2-, 4-, or 6-positions were

• elucidate the role of substituents present in the aromatic part of the N-tosylimines, the monohalogenated N-tosylimines 2d–f and N-tosylimine 2g with a strongly electron-withdrawing CF3 substituent in the 4-position were subjected to the reaction with tripyrrane 1. These para-substituted N-tosylimines

• reactions with N-tosylimines for both A4B2-hexaphyrins and A3B-porphyrins (Table S1 in Supporting Information File 1). Until now, we have investigated the effect of substituents present in the aryl substituent of the N-tosylimines on the product formation. At this point, we chose 5,10-bis(4

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• C [10], leptomerine [11], and punarivine [12]. The fruit of Evodia rutaecarpa is a particularly rich source of 4-quinolones with long-chain substituents at position 2. Various alkaloids isolated from this source have been shown to possess anti-Helicobacter pylori activity [13], inhibitory effects on

• substituents at the C-2 position. As a way of expanding the scope of this methodology, we resorted to the α-C-acylation of β-enamino amides, a reliable reaction, the utility of which we have already demonstrated in other contexts [62][63]. Results and Discussion As the starting point of our synthetic

• key o-nitrobenzoyl intermediates 3 in a reaction with o-nitrobenzoyl chloride (Scheme 1, conditions ii). The acylation of 2 to 3 proceeded with variable yields, depending on the substituents R1 and R2. Derivatives 2 with a primary carboxamide group (R2 = H) gave generally lower and poorly reproducible

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• substituents of molecules 1 and 2. The π electron systems of both molecules are predominantly planar, with 2-iso showing a slight deviation from planarity due to the sterical proximity of the dicarboximide oxygens with the adjacent bay hydrogens. The frontier orbitals and their energies are shown in Figure 8b

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• ; phenol acidity; ring substituents; XRD; Introduction N-Acylhydrazones are a class of compounds that contain the hydrazonic functional group (–NH–N=C–) attached to an acyl group, which can be modified to generate a range of different structures with varying properties [1]. The versatility of this class

• proved the promising anti-PD and metallophoric effect, especially towards intracellularly relevant copper(I) ions, of X1INH (1-methyl-1H-imidazole-2-carboxaldehyde isonicotinoyl hydrazone) [32]. This year, we evaluated the effects of the presence of three methoxy substituents in an N-acylhydrazone

• display a role in neurodegeneration [38]. A comparative study between these two N-acylhydrazones is interesting, especially considering that they possess different substituents at the same position in the phenol ring: the electron-donating methyl group (hdz-CH3) and the electron-withdrawing nitro group

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• . explored the modulation of optoelectrochemical properties and thermal characteristics of pyridopyrazino[2,3-b]indole-based Qx46 series with varying substituents, i.e., bromine, chlorine, methyl and nitro group. Their study revealed inbuilt ICT and aggregation-induced emission (AIE) effects, forming

• emissive nanoaggregates in a THF/H2O mixture. Altering the substituents proved as an effective approach to tune the electrochemical properties of the compounds, resulting in comparable LUMO energy levels. The products therefore hold potential as solid-state emitters and n-type materials for organic

• -phenylindoloquinoxaline (PhIQ) derivatives, shown in Figure 6 as Qx50 series, by chemically modifying the PhIQ groups. In particular, substituents at the 2- and 3-positions of PhIQs were introduced, allowing regulation of the reduction–oxidation potentials of the compounds. The PhIQs exhibited fluorescent solvatochromism

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• cations, while 4,7-dimethoxy substitution leads to more reducing E(1+/1•) values, as well as cathodic shifts in E(12•+/12) and E(1H•+/1H) values. Both the use of 3,4-dimethoxy and 2-aryl substituents accelerates the reaction of the 1H species with PC61BM. Because 2-aryl groups stabilize radicals, 1b2 and

• , which can be advantageous [19]. Although the impact of different 2-aryl Y groups on the reactivity of 1H species have been examined [9][24], there has been no direct comparison of the solution reactivity (or doping behavior) of 1H or 12 reductants with Y = aryl substituents to that of their Y = alkyl

• counterparts, while there has also been limited effort on examining the effects of substituents on the benzimidazole 6-membered ring in either class of reductant [16][24]. Furthermore, there has been little work on Y = 2-thienyl 1H derivatives. Here, we report two new dimers (1g2 and 1h2) and three new hydride

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

• macrocycles in systems designed for reaction-centre-like processes and their usage as potential energy transduction devices [51][76][77]. meso-Crowned porphyrins One of the conceptually most straightforward methods to introduce a crown ether unit into the porphyrin is functionalising the meso-substituents

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• and acceptor molecules (N···F and N···H bonding when using the acceptor Y6), as well as an induced dipole moment in the molecule for increased work function tuning of the cathode. The use of benzyl and pentafluorobenzyl substituents was to evaluate the impact of H vs F on the electrochemical

Cyclodextrins permeabilize DPPC liposome membranes: a focus on cholesterol content, cyclodextrin type, and concentration

• Ghenwa Nasr,
• Hélène Greige-Gerges,
• Sophie Fourmentin,
• Abdelhamid Elaissari and
• Nathalie Khreich

Beilstein J. Org. Chem. 2023, 19, 1570–1579, doi:10.3762/bjoc.19.115

• hydroxypropyl substituents are bulkier and less hydrophobic than the methyl groups resulting in a lower CHOL solubilizing capacity and a weaker hemolytic activity for HP-β-CD [28]. Besides, the ionic β-CD derivatives are less effective in promoting CHOL extraction given that the charge decreases the affinity of

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

• beneficial to the reaction outcome than electron-rich groups in the phenyl ring (3a–f). The crystal structure of product 3i is shown in Figure 2. Also, substituents in different positions of the phenyl ring in acetylene 1 smoothly reacted with NaNO2 under the reaction conditions affording the products in

• , which is an internal alkyne instead of a terminal alkyne, but no desired product was obtained. Next, we explored the substrate scope of 2-methylquinolines under the standard conditions. 2-Methylquinoline bearing different substituents at various positions gave the corresponding products with moderate to

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

• since the selective introduction of substituents at three different positions on the 1,2,3-triazole ring can augment the features of the molecule. Triazoles are also found in many biologically important molecules and functionalized materials [11][12][13][14][15][16]. 1,4,5-Trisubstituted-1,2,3-triazoles

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• affinity and selectivity of the R[4]A–amine complexes depend on several factors, including the size, shape, and functional groups of both the host and the guest molecules. For example, R[4]A derivatives with different substituents on the aromatic rings [12] have been synthesized to enhance the binding

• substituents with R[4]A in ethanol were synthesized. The composition of the complexes was determined based on the integration of amine proton signals in the 1H NMR spectra. For small molecule sec-amines such as N,N-dimethylamine, N,N-diethylamine, and cyclic amines (pyrrolidine, piperidine, morpholine, N

• -methylpiperazine), the complexes with 1:1 stoichiometry were formed. For sec-amines with larger alkyl substituents (dipropylamine, diisopropylamine), complexes with 1:2 stoichiometry were formed. The structure of the complexes with 1:1 stoichiometry varies depending on the type and polarity of the solvent. In DMSO

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

• , chelerythrine analogs with modifications to the ring substituents can be seen as ubiquitous with sanguinarine analogs. Our group has been focused on exploring new compounds with antibacterial and antifungal properties, which may serve to ease the strain caused by the ever-growing list of drug-resistant

• is consistent with previous reports that showed antimicrobial improvement for variants with hydrophobic substituents at position-13 [26][42]. On the other hand, variant B1 was significantly more active against Gram-positive bacteria when compared to original berberine (B). It was also found B1 was

• berberine variants none are as easily modulated to rapidly install substituent diversity [31][43][44][45][46][47][48]. The method deemed most amenable to varying substituents involves substituted 2-bromo-1-aminonaphthalenes which are used in subsequent palladium cross-coupling reactions [45]. As such, our

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• form of the starting compound [Cl3CCH=CHC(=OH+)Me]. The presence of two strong electron-withdrawing substituents, the trichloromethyl group (CCl3) and a protonated carbonyl (C(OH+)Me), at the carbon–carbon double bond makes this O-protonated species electrophilic enough to react with arenes (Scheme 1a

• ). The second protonation of the C=C bond is hampered due to a strong acceptor character of the substituents, contrary to other more donating enones. As a continuation of the research on the electrophilic activation of electron-poor alkenes bearing two electron-withdrawing substituents at the C=C bond

• electron-donating substituents in the aromatic ring gave oligomeric materials. Presumably, in these cases, after dehydration and formation of the corresponding enone 2, the latter underwent subsequent cationic oligomerization. Next we studied the intramolecular cyclization of compounds 1 and 2 in TfOH. It

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• arylaluminium reagents to five-, six-, and seven-membered β-substituted cyclic enones (Scheme 42). It is obvious that the NHC–Cu(I) complexes are generated in situ through transmetallation. For arylation reactions, Me2(Ar)Al reagents were used. The substrates having a variety of substituents (R = CH2Bn, n-Bu

• -hydroboration products. Furthermore, the presence of 2,6-dimethylphenyl-derived N-substituents on the NHC were optimal for the catalysis. Hoveyda and co-workers [87] reported the NHC–Cu(I)-catalyzed site- and enantioselective hydroboration of 1,1-disubstituted aryl olefins to obtain α-alkyl-β-pinacolatoboranes

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• azide was combined with a subsequent copper-catalyzed (3 + 2) cycloaddition with terminal alkynes. This one-pot process was developed with a simple model alkyne, but then applied to more complex alkynes bearing enantiopure 1,2-oxazinyl substituents. Hence, the precursor compounds 1,2-, 1,3- or 1,4-bis

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• attention. Todd et al. reported a method for the cross-dehydrogenation coupling of isochroman C(sp3)–H bonds with anisole C(sp2)–H bonds using CuCl as a catalyst and DDQ as an oxidant (Scheme 11) [61]. However, this method is not ideal for tolerating substrates with electron-donating substituents (such as 1

• -economical CDC reaction of coumarin and flavonoids with different ethers through a C(sp3)–H activation process and obtained two novel ether-substituted derivatives (Scheme 24) [85]. This method can introduce ether substituents at the electron-rich α-position of coumarin and the β-H position of flavonoids. In

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

• conditions in hand, the scope of the reaction was investigated by using various substrates. The results are summarized in Table 2. All reactions proceeded smoothly to give the desired dispiro compounds 3a–m in satisfactory yields. Various isatins with different substituents can be successfully used in the

• reaction. The substituents showed marginal effects on the yields. On the other hand, the dimedone adducts of alkyl 2-(2-oxoindolin-3-ylidene)acetate with various substituents were also successfully employed in the reaction to give the desired products. It can be seen that the dimedone adducts of alkyl 2-(2

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

• Liang also assessed the effect of ortho-substituents on iodonium ylides undergoing radiofluorination, similar to that encountered with diaryliodonium salts [135][136][137][138]. They prepared a series of ylides (61a–d) with substituents situated ortho- or para- to iodine, and found the radiochemical

• bonding occurring between the Lewis basic ether and a σ-hole on the electropositive iodine (Scheme 14, inset). These results suggest that with iodonium ylides, ortho-substituents impose an electronic effect (compare 62a vs 62b and 62b vs 62c), contrary to the steric effect observed for radiofluorination

• reaction’s outcome. Additional examples of intramolecular secondary interactions also exist in the literature, in which ortho-substituents on iodoarene-derived ylides have been key to tuning reactivity and improving reaction outcomes. Zhdankin et al. first reported on this concept, testing ortho-alkoxy

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

• limited to electron-poor arenes like diazonium/iodonium salts or aryl iodides with electron-withdrawing substituents as aryl radical precursors, due to the limited accessible reducing power of photocatalysts that relied on a monophotonic excitation event. However, the vast majority of inexpensive

Synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazines

• Dmitry B. Vinogradov,
• Alexei N. Izmest’ev,
• Angelina N. Kravchenko,
• Yuri A. Strelenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2023, 19, 1047–1054, doi:10.3762/bjoc.19.80

• ][1,2,4]triazine or imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazine and the expansion of the thiazolidine ring to a thiazine core. The methodology proved to be effective for the preparation of a series of target compounds with different substituents in the tricyclic fragment. Examples of natural and

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• capability of the PTZ and NI moieties, respectively, by oxidation of the PTZ unit, or by using different aryl substituents attached to the NI unit. This tuning effect was manifested in the UV–vis absorption and fluorescence emission spectra, e.g., in the change of the charge transfer absorption bands. TADF

• was observed for the dyads containing the native PTZ unit, and the prompt and delayed fluorescence lifetimes changed with different aryl substituents on the imide part. In polar solvents, no TADF was observed. For the dyads with the PTZ unit oxidized, no TADF was observed as well. Femtosecond

• different aryl substituents, which contain both electron-donating and -withdrawing moieties. Although we reported NI-PTZ analogous dyads recently, they were not studied by fs-TA spectroscopy and the molecular structures are different from the current dyads [39][47]. The photophysical processes of the dyads

Copper-catalyzed N-arylation of amines with aryliodonium ylides in water

• Kasturi U. Nabar,
• Bhalchandra M. Bhanage and
• Sudam G. Dawande

Beilstein J. Org. Chem. 2023, 19, 1008–1014, doi:10.3762/bjoc.19.76

• -methoxyphenyl)-λ3-iodaneylidene)cyclohexane-1,3-dione (2b) under identical reaction conditions. The arylamines with having p-OMe, m-NO2, and p-bromo substituents reacted efficiently with iodonium ylide 2b to form their diarylamine derivatives 3o–q with 74–86% yields. Next, we scrutinized the CuSO4·5H2O