Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• batteries, due to the ease of their structural modification, rich redox chemistry, and robust coordination M–N4 environment [100][101][102][103][104][105]. The key processes employed in energy transfer and storage are the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• properties. Due to the low solubility of violanthrone in the majority of organic solvents, special attention has been drawn to its dihydroxy derivative (Figure 1), which allows further modification to the materials via etherification or esterification [29][30]. There has been a report on the structural

• modification of dihydroxyviolanthrone where the effect of three alkoxy substituents on the 16,17-bis(2-ethylhexyloxy)anthra[9,1,2-cde]benzo[rst]pentaphene-5,10-dione, on aggregation and photovoltaic properties was studied [30]. It was found that derivatives with the shortest linear alkyl chain (n-hexyl

Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• influence on the properties and thus performance of the resulting heterogeneous catalyst. However, immobilisation and structural modification introduce additional steps in the synthesis of the catalyst. Moreover, the catalytic activity and selectivity of immobilised catalysts are often lower than those of

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• pentacyclic scaffolds. The designed and chemically synthesized substrate analog 96 was tolerated by the key NRPS module SfmC despite the structural modification (Scheme 10A). In vitro enzymatic conversion of 96 with tyrosine derivative 86 [103] followed by the addition of KCN concisely furnished the

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

• circumstances, considerably impacting their pharmacological utility [19][20], Moreover, the conventional CRBN recruiters restrict structural modification options necessary to maintain satisfactory affinity for the E3-ligase [21][22][23][24]. These limitations underscore the relevance of expanding the chemical

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

• of structural modification, the introduction of various functional groups into Qx derivatives has allowed for the precise control of energy levels, bandgaps, and carrier transport properties. For instance, Sharma et al. fine-tuned the intermolecular charge transfer (ICT) transitions and emission

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

• structural modification, this was chosen as the path towards enhancing the activity of B1. As shown in Scheme 5, we reduced B1 to produce B14, which was then screened against our panel of microbial organisms (Table 2). We were very pleased with the results of B14, representing a near universal improvement

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

• installation of the phosphocholine moiety (67%) followed by the deprotection of the secondary alcohol (100%) and its acetylation (53%) produced 13.6. Wissner et al. also reported the incorporation of a gem-dimethyl substituent on the glycerol backbone [97]. One illustration of this structural modification is

• alcohol produced 27.6 that, in a two-step sequence, was used to install the phosphocholine moiety to produce 27.8. The double structural modification of edelfosine that consists to link the lipid chain via a thioether function and to replace the phosphate moiety by a thiophosphate was reported by

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• mediators that can be recycled photo- and electrochemically [45][49]. As illustrated in Figure 5, structural modification of the benzimidazole core alters the redox behavior and allows tuning of the oxidation potential. The benzimidazoles shown all have enough reducing power to reductively quench Ru(bpy)3

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

• hard fluoride interacts with the stronger σ-hole. Structural modification of the β-dicarbonyl auxiliary has led to improved outcomes, due to increased ylide stability rather than decreasing activation energies of the fluorination reaction. There are, however, other conflicting pieces of evidence that

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

• 15 and 19 was also performed with the aim to increase the enantiomeric purity of the corresponding nitroaldol products 21–26. The structural modification consisted in the introduction of different alkyl moieties to the carbamate functional group of the aldehyde intermediates 15–20. As bulky and/or

•  2). The bulky (R2 = t-Bu) or chiral (R2 = ʟ-menthyl or (−)-bornyl) alkoxy groups (derived from relatively inexpensive and readily available alcohols) were introduced into the carbamate moiety instead of an ethyl group as in aldehydes 15 and 19. Here, the influence of this structural modification of

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

• Shrikant D. Tambe,
• Kwan Hong Min,
• Naeem Iqbal and
• Eun Jin Cho

Beilstein J. Org. Chem. 2020, 16, 1335–1342, doi:10.3762/bjoc.16.114

• hypothesized that the structural modification of the substrate might affect its reactivity, and to our delight, the introduction of an ortho-phenyl moiety on the N-benzylideneaniline species provided the desired 1,2-diamine product, wherein the N,N-dicyclohexylmethylamine (Cy2NMe) acted as both the coupling

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• approximation, to study the effect of these structural modification on the pharmacodynamics, we performed a molecular docking over two MPPs. In Table 4, the interaction energy value (MolDock Score) [38] of each compound with the two different MMPs obtained from the docking calculation is displayed. Also, the

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• (Figure 2A), which show prominent fluorescence not only in dilute solution, but also in the crystalline state [27][28][29][30][31]. As a powerful tool to develop novel pure organic phosphorescent molecules, we envisioned the structural modification of the carbon–carbon triple (C≡C) bond in fluorinated

• effects of structural modification (i.e., the benzil structure with a tolane vs bisbenzil moiety) and incorporation of fluorine atoms on the phosphorescence, the ratio between the peak intensities at ≈395 and ≈560 nm (I560/I395) was quantitatively calculated, and the results are summarized in Table 1. The

Synthesis of 9-O-arylated berberines via copper-catalyzed C_Ar–O coupling reactions

• Qiaoqiao Teng,
• Xinhui Zhu,
• Qianqian Guo,
• Weihua Jiang,
• Jiang Liu and
• Qi Meng

Beilstein J. Org. Chem. 2019, 15, 1575–1580, doi:10.3762/bjoc.15.161

• 9-O-phenylene-bridged berberine dimer (5) was synthesized by copper-catalyzed cross-coupling of tetrahydroberberrubine and aryl iodides, followed by oxidation with I2. Keywords: arylation; berberines; cross-coupling; copper; lipophilicity; structural modification; Introduction Berberine (BBR) is a

Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce

• Hidekazu Komatsu,
• Takashi Shirakawa,
• Takeo Uchiyama and
• Tsutomu Hoshino

Beilstein J. Org. Chem. 2019, 15, 299–309, doi:10.3762/bjoc.15.27

• treatment had no activity, supporting that a macrocyclic peptide would be essential for biological activity. The sequence Z-dhThr17-D-alloThr18 of cichorinotoxin was converted to Z-dhThr17-E-dhThr18 by alkaline hydrolysis. This additional structural modification may have further decreased the activity

Semi-synthesis and insecticidal activity of spinetoram J and its D-forosamine replacement analogues

• Kai Zhang,
• Jiarong Li,
• Honglin Liu,
• Haiyou Wang and
• Lamusi A

Beilstein J. Org. Chem. 2018, 14, 2321–2330, doi:10.3762/bjoc.14.207

• as the glycosylation donor of C9–OH, but also the protecting group of C17–OH, greatly reducing the synthetic steps and costs. Macrolide compounds are a new kind of insecticides and fungicides which have also been widely applied in medicine [14][15]. Currently, research on structural modification of

Functionalization of graphene: does the organic chemistry matter?

• Artur Kasprzak,
• Agnieszka Zuchowska and
• Magdalena Poplawska

Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177

• effects and to open new avenues for the application of GO and RGO, a chemical functionalization was conducted [9][10][11][12]. There are two approaches for the structural modification of GO and RGO: (i) the reaction of oxygen-bearing groups or (ii) the functionalization of sp2 carbons from the graphene

• functionalization of the graphene-family material. In fact, the structural modification of GO and RGO constitutes a key starting point of such research. Even though many studies on chemical functionalization have presented very interesting and novel applications of GO and RGO derivatives they also present yet

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• between hundreds of nanoseconds to several microseconds, constituting a formally spin-forbidden transition (phosphorescence). Structural modification of the TMCs and proper tailoring of coordinated ligands can independently act on the nature, energy and topology of frontier orbitals. In fact, a fine

Synthesis of fluoro-functionalized diaryl-λ³-iodonium salts and their cytotoxicity against human lymphoma U937 cells

• Prajwalita Das,
• Etsuko Tokunaga,
• Hidehiko Akiyama,
• Hiroki Doi,
• Norimichi Saito and
• Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

• suggested that antitumor drug candidates could be designed by further structural modification of these compounds 3. Moreover, with 3p exhibiting the greatest potency against U937 cells with comparably lower toxicity against AGLCL cells, further biological studies using 3p including in vivo evaluation should

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• Cs2CO3 for 3 hours finally afforded phenytoin in an excellent 84% isolated yield (Scheme 16c). The introduction of a sulfonyl group on the urea framework has been found to be the crucial structural modification in the development of the 1st generation antidiabetic drugs such as tolbutamide and

Synthesis of acylhydrazino-peptomers, a new class of peptidomimetics, by consecutive Ugi and hydrazino-Ugi reactions

• Angélica de Fátima S. Barreto,
• Veronica Alves dos Santos and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2016, 12, 2865–2872, doi:10.3762/bjoc.12.285

• peptidomimetics with potential biological activity. Keywords: acylhydrazino-peptomers; consecutive Ugi reactions; peptide-peptoid hybrid; peptomer; Introduction In the last decades, increasing efforts have been extensively carried out to improve the pharmacological properties of natural peptides by structural

• modification of the amino acids [1][2][3][4][5][6][7][8]. These modifications allowed the obtention of molecules that mimic the properties of peptides (peptidomimetics) but usually exhibit greater proteolytic stability, increased cellular permeabilities and avoid stereochemical constraints. Figure 1 represents

Towards the development of continuous, organocatalytic, and stereoselective reactions in deep eutectic solvents

• Davide Brenna,
• Elisabetta Massolo,
• Alessandra Puglisi,
• Sergio Rossi,
• Giuseppe Celentano,
• Maurizio Benaglia and
• Vito Capriati

Beilstein J. Org. Chem. 2016, 12, 2620–2626, doi:10.3762/bjoc.12.258

• advantages in terms of reaction sustainability. In particular, the possibility to strongly reduce the amounts of organic solvent and the recyclability of the catalyst were demonstrated [23]. Moreover, in this approach, no structural modification of the precious chiral catalyst was necessary. A well-explored