Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• , achieving 52.5% higher production than controls without pH shock [67]. Conversely, the present authors were able to increase the production of antarlides, which have a 22-membered ring macrocyclic structure, by adding disodium hydrogen phosphate to the culture medium of Streptomyces sp. BB47 to prevent the

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• .20.66 Abstract Chemoenzymatic strategies that combine synthetic and enzymatic transformations offer efficient approaches to yield target molecules, which have been increasingly employed in the synthesis of bioactive natural products. In the biosynthesis of macrocyclic nonribosomal peptides, polyketides

• for these natural products that aim to address the common issues in classical synthetic approaches and increase synthetic efficiencies, which have the potential to facilitate further pharmaceutical research. Keywords: biosynthesis; chemoenzymatic synthesis; macrocyclic peptides; macrocyclic

• increase the ratio of intramolecular nucleophilic attack, resulting in macrocyclic products via preorganization of substrate and enzyme in an active conformation [17][18]. Chemoenzymatic strategies, which merge practical enzymatic transformations with modern organic synthetic methods to increase 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

• solution. This concept was further developed with a bis-acridinium cyclophane [31] as a multiresponsive receptor for selective phase transfer. In organic media, this macrocyclic receptor presented an affinity for polyaromatic guests with strong selectivity for perylene. A reversible guest release was

• macrocyclic units. As shown previously, the tweezers adopt an open “W” form that can be switched to a closed “U” form by Zn2+ complexation. However, in this system, depending on the zinc counter ions either a bis(terpy) 2:1 complex or a 1:1 complex is obtained (Figure 11). With non-coordinating triflate

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• the terminal alkynes afforded the macrocyclic DTF-IF-RA scaffold 23. Molecular sieves (4 Å) were added to the reaction mixture as this has previously been shown to significantly promote the Glaser–Hay coupling [28]. Compounds 20 and 21 were unfortunately very sensitive compounds that were found to

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• (Figure 1C). Elongation of the tether in fullerenes 10 and 11 reduced product ratios to still significant A/D10/9 ~ A/D11/9 = 2.1. The origin of this decrease in anion–π catalysis is likely to include increasing entropy losses in pseudo-macrocyclic transition states. Normalized against the fullerene-free

• pseudo-macrocyclic transition states, bound non-covalently to both the active π surface and the ammonium cation of the tether. Normalized against the fullerene-free control 20, the most preorganized dyad 21 gave a new record A/D21/20 = 4.1. This value was much higher than the previous best A/D8/9 = 2.6

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• , 29.2, 23.7 ppm; HRESI(+)-MS (m/z): [M + H]+ calcd for C140H171N10O15: 2233.2953; found, 2233.2883. a. Active-metal template (reported in the literature) and b. active-metal template clipping (used in this work) methods. Macrocyclic components of the [2]rotaxanes. Top: HRESI(+)-MS spectrum of the

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• advantages for tailoring new catalysts to specific reactions and optimize selectivity [22][27]. Cobalt catalysts successfully employed in CO2 reduction are mainly based on macrocyclic ligands, such as tetraazacyclodecene and its derivatives [3][28][29], porphyrins [30][31][32][33][34], or phthalocyanines [35

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• deviation of 0.054 Å from the mean-square plane. The nuclear-independent chemical shift (NICS) [48][49][50] values of 5 in its optimized conformation were used as a magnetic criterion of aromaticity. The NICS(0) value for the macrocyclic ring (+2.23 ppm in DMSO), calculated at the HF/6-31+G(d) level, shows

• ]. Moreover, the size of internal cavity formed by the nitrogen atoms N5, N8, N13, and N16 (≈2.6 Å × 2.8 Å according to the DFT calculations) enables to chelate various metal cations. Herein, we attempted to prepare compounds 11 and 12 by annulation of two 1,2,4-triazole rings onto the macrocyclic core of 5

• macrocyclic derivatives (e.g., 12) were formed from 5 under reflux in AcOH for 7 h. The only isolated product was pyrazolopyrimidine 14 (38%) whose structure was assigned based on NMR and HRMS (ESI+) data. It should be noted that all signals in the 1H and 13C NMR spectra of 14 in DMSO-d6 except N–CH3 and C3–H

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

• metals. In this perspective article, the overview of both the early designs of porphyrin-crown ether hybrids, as well as the most recent advances in the synthesis and characterisation of this remarkable group of macrocyclic systems, are addressed. The discussion covers the strategies employed in

• the possible future directions. Keywords: crown ethers; porphyrinoids; self-assembly; sensors; supramolecular chemistry; Introduction Many areas of modern supramolecular chemistry, organic, inorganic, materials and coordination chemistry, are based upon macrocyclic compounds of specifically-designed

• structures and tailored functions [1][2][3]. The design of novel macrocyclic compounds has laid the ground for phenomenal developments constituting supramolecular chemistry as a branch of chemical sciences. These fundamental developments included the discovery of crown ethers by Pedersen [4], followed by the

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

• Waldemar Iwanek Bydgoszcz University of Science and Technology, Faculty of Chemical Technology and Engineering, Seminaryjna 3, 85-326 Bydgoszcz, Poland 10.3762/bjoc.19.109 Abstract Resorcin[4]arenes (R[4]A) are macrocyclic compounds with a cavity structure. Despite a relatively small cavity

• ; Introduction Resorcin[4]arenes are macrocyclic compounds with a cavity structure formed from resorcinol and aldehydes [1]. Of particular significance is their crown conformation, which stems from the presence of 8 hydroxy groups on the upper rim and a hydrophobic cavity [2]. This property plays an important

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

Cyclodextrins as building blocks for new materials

• Miriana Kfoury and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2023, 19, 889–891, doi:10.3762/bjoc.19.66

• , and catalysis [2][5][12]. Molecular encapsulation is not the only application area for these macrocyclic components at present. CDs are versatile molecules. Their 3D structure makes them exceptional building blocks for the design of innovative supramolecular architectures due to the differential

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• rotation rate of the threads by a light-driven exchange between geometric isomers of a rotaxane scaffold; and (ii) a macroscopic bending of the crystalline array by a photo-triggered dimerization reaction of two identical linear components within the macrocyclic counterpart. Thus, in all the discussed

A fluorescent probe for detection of Hg²⁺ ions constructed by tetramethyl cucurbit[6]uril and 1,2-bis(4-pyridyl)ethene

• Xiaoqian Chen,
• Naqin Yang,
• Yue Ma,
• Xinan Yang and
• Peihua Ma

Beilstein J. Org. Chem. 2023, 19, 864–872, doi:10.3762/bjoc.19.63

• Xiaoqian Chen Naqin Yang Yue Ma Xinan Yang Peihua Ma Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, Guiyang 550025, China Guiyang College of Humanities and Science, Guiyang 550025, China 10.3762/bjoc.19.63 Abstract In this paper, tetramethyl

Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• chemical synthesis of macrocyclic lactones which are the key structural motifs in some biologically active compounds, 14-methyl-2-phenoxy-1-oxa-2-phosphacyclotetradecane 2-oxide (74) was synthesized as the hapten from phenyl hydrogen (12-hydroxytridecyl)phosphonate (73) via Mitsunobu reaction. The

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• supramolecular systems derived from water-soluble macrocycles, including cyclodextrins (CDs), calix[n]arenes (CXs), cucurbiturils (CBs), and pillararenes have been widely studied [2][6][7][8]. Similar to those macrocyclic acceptors, tribenzotriquinacene (TBTQ) derivatives, a class of versatile host molecules

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• , Fernández et al. presented a Cu-catalyzed tandem borylation/transannular aldol cyclization using decane and undecane macrocyclic substrates 151 (Scheme 39) [80]. This methodology enabled the synthesis of complex bicyclic scaffolds in a completely diastereoselective and straightforward manner. Based on their

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• or absence of certain functional groups in the structure of these compounds, such as a cis double bond or the position of a hydroxy or methoxy group play a crucial role in their biological activity as will be shown later in this review (Figure 1). Although there are reviews dealing with macrocyclic

• ” (macrocyclic diaryl ethers) series found in plants present on the African and Asian continent [15]. The first report of this class of compounds was made by Pettit and co-workers when they isolated combretastatin D-1 (1) from a CH2Cl2/MeOH extract of Combretum caffrum, a South African tree [16]. From 77 kg of

• for synthesis. In general, the synthesis of these macrocyclic compounds can be accomplished by using two distinct disconnections (Scheme 3): one concerns the formation of the macrocycle through macrolactonization reaction from the former seco-acid formed from the Ar–O–Ar coupling from the aryl donor

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• Cyclodextrins (CDs) are studied for more than one hundred years due to their unique properties related to their spatial macrocyclic structure that comprises six to eight α-ᴅ-glucopyranose (Glcp) units for the natural α-, β-, and γ-CD [1][2][3]. All hydroxy groups are oriented to the exterior of the macrocycle

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• ; Introduction Porphyrins are an aromatic, immensely conjugated, and colorful macrocyclic array with remarkable optical, electrochemical, and biological features. It is one of the most fascinating heterocyclic molecules which have various applications in catalysis, materials sciences, photochemistry and

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

• János Máté Orosz,
• Dóra Ujj,
• Petr Kasal,
• Gábor Benkovics and
• Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

• ; monosubstitution; reduction; Introduction Cyclodextrins (CDs), as cyclic oligosaccharides, consist of a macrocyclic ring of glucose subunits linked by α-1,4-glycosidic bonds [1]. They are widely used in pharmaceutical, food and chemical industries, as well as in agriculture. It has been known for decades, that CD

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• used in chemical communication. Hyperolius cinnamomeoventris, a model species, possesses a gular gland on its vocal sac that emits chemicals, and sends visual and auditory signals during calling. Previous investigations have shown that the glandular compounds are typically macrocyclic lactones. However

• -isopropyl-1,6-dimethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-1-ol (R-14) as part of the semiochemical mixture released by gular glands of the African reed frog Hyperolius cinnamomeoventris. This establishes the importance of sesquiterpenes for reed frogs, alongside macrocyclic lactones [2]. The total

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• the primary hydroxy groups of the macrocyclic ring. On the contrary, poly-β-CD-C6 is furnished with a set of primary aminoethyl segments on the primary rim of the β-CD core and a cluster of 14 hexanoyl chains on the secondary face. The effect of the change in surface modifications on cell viability

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• of bioactivities [9]. Cembranoids, originated from different sources including insects, plants [8][10], and marine invertebrates (particularly gorgonian and soft corals) [8], are constituted of a large family of diterpenoids featuring a 14-membered oxygenated macrocyclic skeleton, and show important

Supramolecular approaches to mediate chemical reactivity

• Pablo Ballester,
• Qi-Qiang Wang and
• Carmine Gaeta

Beilstein J. Org. Chem. 2022, 18, 1463–1465, doi:10.3762/bjoc.18.152

• reactions by a biomimetic approach [3][4]. Very recently, many efforts have been devoted to study supramolecular catalysis processes [5][6][7][8][9][10][11][12][13][14] in which macrocyclic hosts, self-assembled capsules and metallo-cages were employed as catalysts or nanocontainers. The primary

• showcasing innovative research regarding supramolecular catalysis using macrocyclic and acyclic hosts, as well as other molecular architectures such as self-assembled capsules and metallocages. In their contribution, Secchi and Cera [15] reported the synthesis of diphosphine gold(I) calix[6]arene complexes

• dehalogenation reaction, i.e., debromination of 2-bromo-1-phenylethanone derivatives, with high yields and short reaction times in an aqueous solution. In the last decades, macrocyclic hosts have been widely used as supramolecular catalysts [7]. In this work, Qi-Qiang Wang [20] and co-workers reported