3-Aryl-2H-azirines as annulation reagents in the Ni(II)-catalyzed synthesis of 1H-benzo[4,5]thieno[3,2-b]pyrroles

• Julia I. Pavlenko,
• Pavel A. Sakharov,
• Anastasiya V. Agafonova,
• Derenik A. Isadzhanyan,
• Alexander F. Khlebnikov and
• Mikhail S. Novikov

Beilstein J. Org. Chem. 2025, 21, 1595–1602, doi:10.3762/bjoc.21.123

• unique ability of these compounds to undergo selective opening of the three-membered ring at either of the two nitrogen–carbon bonds under certain conditions and to be incorporated into the target molecule as a N‒C‒C synthon is successfully used to obtain a variety of heterocyclic and acyclic nitrogen

pH-Controlled isomerization kinetics of ortho-disubstituted benzamidines: E/Z isomerism and axial chirality

• Ryota Kimura,
• Satoshi Ichikawa and
• Akira Katsuyama

Beilstein J. Org. Chem. 2025, 21, 1568–1576, doi:10.3762/bjoc.21.120

• calculated the distance between the imino carbon atom and the nitrogen atom of the NMe₂ moiety (d) for local minimum and transition-state structures (Figure 2). In the local minimum and transition state of the C–N rotation and C–N/C–C concerted rotation, protonation leads to a shortening of the C–N bond by

• made with little effect on the molecular structure and are widely used in areas such as carbon materials. If the three-dimensional structure of molecules can be manipulated by various external stimuli through such modifications, we can expect to develop useful molecular switches that can be applied to

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• ][2][3][4][5]. In addition to these promising functionalities, their cyclic polyaromatic frameworks can be further transformed into fused structures. To this end, belt-like polyaromatic architectures can be developed, inspiring ongoing efforts toward the construction of carbon nanotube analogs (Figure

Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins

• Juliana V. Petrova,
• Varvara T. Tkachenko,
• Victor A. Tafeenko,
• Anna S. Pestretsova,
• Vadim S. Pokrovsky,
• Maxim E. Kukushkin and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118

• another cycle via the single quaternary carbon atom C5 demonstrated significant biological activity, greater than analogs with non-spiro-bonded cyclic fragments [3][4]. Hydantoin derivatives also exhibit a wide range of biological activities. Compounds containing the hydantoin pharmacophore group, are

• more electronegative oxygen or nitrogen atoms, both in the HOMO of dipole and dipolarophile [36][39]. In contrast, the carbon atoms have a significantly higher orbital coefficient than the heteroatoms, both in the LUMOdipolarophile and the LUMOdipole. Thus, nitrile oxide tends to react with an imine to

• form two new carbon–heteroatom bonds in a 1,2,4-oxadiazoline ring through both variants of orbital overlap. It should be noted that, in this case, NMR spectroscopy is not applicable to assign the product structure due to the presence of only quaternary carbon atoms in the tetrasubstituted 1,2,4

Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent Cyrene^TM under one-pot conditions

• Zoltán Medgyesi and
• László T. Mika

Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117

• and atom-economical strategies for efficiently assembling new carbon–carbon [1][2][3] and carbon–heteroatom [4][5][6] bonds. Thus, it has become the most attractive and facile methodology for creating various complex organic molecular structures from the laboratory to the industrial scale. Among these

• successfully introduced into homogeneous [26][27][28][29] and heterogeneous [30][31] carbon–carbon and carbon–heteroatom bond-forming protocols. Although its reactive carbonyl group could limit its application when a strong base (aldol condensation [29]) or amines (potential Schiff-base formation) are present

• -triazoles in CyreneTM (Figure 4). It was shown that the protocol resulted in the formation of products 3a and 5b–f with yields of 57–91% depending on the structure of the bromide derivatives. The isolated yields were in the same range as reported by Citarella et al. [39]. The presence of a terminal carbon

General method for the synthesis of enaminones via photocatalysis

• Paula Pérez-Ramos,
• Raquel G. Soengas and
• Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

• ; enaminones; nickel; photocatalysis; Introduction Enaminones are relevant intermediates in organic chemistry and the pharmaceutical industry [1][2][3][4][5][6]. These enamines have a carbonyl group conjugated to a carbon–carbon double bond, owing its great versatility in organic synthesis to its ability to

• electrophilicity of the β-carbon due to the electron-donating nature of the methyl group. Subsequently, we turned our attention to investigate a range of amine derivatives 8 under the standard conditions. When morpholine was replaced by piperidine, the expected enaminone 9g was provided, albeit in lower yield

• mechanism for this reaction is proposed in Scheme 5. A ternary complex is initially formed upon complexation of 3-bromochromone (7a) with NiBr2-dmbpy. By virtue of being coordinated to a Ni-center, the β-carbon is activated toward nucleophilic attack of the amine, furnishing 2-amino-3-bromochromenone I

Calcium waste as a catalyst in the transesterification for demanding esters: scalability perspective

• Anton N. Potorochenko and
• Konstantin S. Rodygin

Beilstein J. Org. Chem. 2025, 21, 1520–1527, doi:10.3762/bjoc.21.114

• phase (with reflections at 2θ = 32.4, 37.5, 54.0, 64.3, 67.5) to 73.5 wt % was detected due to the decomposition of the Ca(OH)2 phase; the amount of the Ca(OH)2 phase after calcination was 2.4 wt %. The amount of the CaCO3 phase increased to 17.6 wt %, probably due to the sorption of carbon dioxide or

Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones

• Grzegorz Mlostoń,
• Małgorzata Celeda,
• Marcin Palusiak,
• Heinz Heimgartner,
• Marta Denel-Bobrowska and
• Agnieszka B. Olejniczak

Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113

• of non-concerted, step wise cycloadditions leading to mixtures of five- and seven-membered heterocyclic products (cycloadducts), and respective zwitterionic intermediates were postulated to explain the unexpected reaction pathway [11]. Due to the practically equal electronegativity of carbon and

• analysis (Figure 1a and Figure 1b, respectively). Single crystals of 9i and 10i were obtained by slow evaporation from a hexane/CH2Cl2 solution and subsequently used for crystallographic X-ray measurements. In the case of 9i, the molecule is strongly disordered in the outer carbon ring regions. However

Heterologous biosynthesis of cotylenol and concise synthesis of fusicoccane diterpenoids

• Ye Yuan,
• Zhenhua Guan,
• Xue-Jie Zhang,
• Nanyu Yao,
• Wenling Yuan,
• Yonghui Zhang,
• Ying Ye and
• Zheng Xiang

Beilstein J. Org. Chem. 2025, 21, 1489–1495, doi:10.3762/bjoc.21.111

• enzymatic terpene cyclization and chemical synthesis [30][31][32][33]. Briefly, the carbon scaffolds are forged by terpene cyclases, followed by concise chemical transformations to yield the desired natural products. Here, we describe heterologous biosynthesis of cotylenol by engineering the biosynthetic

• biosynthetic pathway for brassicicenes, which share the same carbon skeleton and similar oxidation and unsaturation states as cotylenol and cotylenin A [36]. In a previous study, Oikawa and co-workers reported the identification of brassicicene BGC in Pseudocercospora fijiensis [37]. By heterologous expression

Copper catalysis: a constantly evolving field

• Elena Fernández and
• Jaesook Yun

Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109

• allenes with diisobutylaluminum hydride, which is followed by the allylation with p-toluenesulfonyl cyanide in a regio- and stereoselective manner. They propose a new way to access accessing acyclic β,γ-unsaturated nitriles with α-all-carbon quaternary centers. In the process, they managed to achieve a

Wittig reaction of cyclobisbiphenylenecarbonyl

• Taito Moribe,
• Junichiro Hirano,
• Hideaki Takano,
• Hiroshi Shinokubo and
• Norihito Fukui

Beilstein J. Org. Chem. 2025, 21, 1454–1461, doi:10.3762/bjoc.21.107

• containing one or two exocyclic olefin units. Owing to the transformation of carbonyl groups, the resulting products exhibit several unique physical and chemical properties: (1) the enhancement of configurational stability, (2) the appearance of fluorescence, and (3) the reductive carbon–carbon-bond

• . A tentative mechanism that may be plausible is shown in Supporting Information File 1, Figure S21, which consists of (1) the nucleophilic attack of methylenetriphenylphosphorane to the exo-methylene group of 3, (2) the intramolecular carbon–carbon-bond formation at the carbonyl group, and (3) the

• Cc space groups, respectively. The bond lengths at the exocyclic olefin units of 3 and 5 are 1.336(2) and 1.333(3)–1.337(3) Å, respectively, which are typical for carbon–carbon double bonds. The (CH2CH2O)-substituted DBC derivative 4 adopts a double-helicene-like structure similarly to other

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• structures, enhance solubility, and expand functional diversity [6]. Substituting carbon atoms with electron-deficient nitrogen atoms introduces new opportunities to fine-tune redox potentials, charge-transport behavior, and intermolecular interactions [7]. These modifications have proven especially valuable

• demonstrated absorption at 368 and 516 nm, strong emission at 553 nm, a high PLQY of 0.96, |gabs| of 1.1 × 10−2, |glum| of 9.1 × 10−4, and BCPL of 30.1 M−1 cm−1 – surpassing the performance of its all-carbon and thiadiazole counterparts [29]. In a related study, Hu’s team synthesized double aza[5]helicenes 17a

Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds

• Lidia Zaharieva,
• Vera Deneva,
• Fadhil S. Kamounah,
• Nikolay Vassilev,
• Ivan Angelov,
• Michael Pittelkow and
• Liudmil Antonov

Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105

• is a result of fast exchange between 1E and 1KE and the minor conformer can be attributed to 1KK. The measured carbon spectrum of 1 in CD3CN at 243 K (Figure S8 in Supporting Information File 1) supports this assignment as well. The HSQC spectrum (Figure S9 in Supporting Information File 1) helps in

• the assignment of the carbon spectrum. The proton signal at 16.59 ppm seems to be a sum of two signals and a deconvolution with Lotenzian bandshape function was performed (Figure S5 in Supporting Information File 1). The obtained two signals have an integral intensity of 78 to 22, which is in

• GIAO approximation [120]. The calculated absolute shieldings were transformed to chemical shifts using the reference compound tetramethylsilane (Si(CH3)4), for hydrogen and carbon atoms: δ = δcalc(ref) − δcalc. Both δcalc(ref) and δcalc were evaluated at the same computational level (M06-2X/TZVP

Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles

• Vladimir G. Ilkin,
• Pavel S. Silaichev,
• Valeriy O. Filimonov,
• Tetyana V. Beryozkina,
• Margarita D. Likhacheva,
• Pavel A. Slepukhin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104

• 2,3-dihydro-1,2-thiazole ring are in the range of 75.3–72.4 ppm and signals of the carbon atom of the cyano group in the range of 117.7–116.6 ppm. The structure of 2,3-dihydro-1,2-thiazole 3aa was additionally confirmed by single crystal X-ray diffraction (Figure 2). According to the X-ray diffraction

N-Salicyl-amino acid derivatives with antiparasitic activity from Pseudomonas sp. UIAU-6B

• Joy E. Rajakulendran,
• Emmanuel Tope Oluwabusola,
• Michela Cerone,
• Terry K. Smith,
• Olusoji O. Adebisi,
• Adefolalu Adedotun,
• Gagan Preet,
• Sylvia Soldatou,
• Hai Deng,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2025, 21, 1388–1396, doi:10.3762/bjoc.21.103

• File 1, Figures S1–S4) of 1 measured in deuterated DMSO revealed well-defined proton signals identified as four aromatic sp2 methines, two aliphatic sp3 methines, a methyl group and four quaternary carbon signals at δC 157.7 (C-1), δC117.8 (C-6), δC 167.2 (C-7), and δC 172.9 (C-10). The presence of a

• (δH 1.10, d, J = 6.9 Hz) revealed the presence of a threonine moiety in 1. Strong HMBC correlations from H-5, H-8 and H-9 to the carbonyl carbon C-7 (δC 167.2) confirmed an amide bond by which the salicylic acid and threonine residues were linked. The deshielded carbon signal at δC 172.9 was assigned

• signal at δH 8.97 (s, H-18), δH 7.41 (s, H-20) and a quaternary carbon (C-16) assigned at δC 131.4 that reminiscences a histamine subunit absent in compound 1. This observation was supported by the 1H-1H COSY spectrum that displayed a cross-peak coupling of H2-14 to both carboxamide protons H-13 and H2

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• after deprotonation of a suitably functionalised ether at the α-carbon. Therefore, a stabilising group must be incorporated to control regioselectivity of the deprotonation as well as to increase the acidity of the α-hydrogen. Mordini et al. showed that even weakly stabilising groups such as phenyl

• react through the terminal carbon and deliver tetrahydrooxepines, especially, if the oxirane is monosubstituted (58, R1 = H). The deprotonation step can also be enabled by employing classical electron-withdrawing groups such as esters, and a particularly powerful methodology was disclosed by Bull and

• to a potentially even larger library of amide isosteres. The scope of the carbon nucleophiles is very broad and includes alkyls, alkenyls, alkynyls, aryls and heteroaryls (e.g., pyridine, indole, thiophene), as well as (poly)substituted phenyls bearing a nitrile or halogen(s). On the other hand, the

Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• 450002, PR China National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Nanjing Forestry University, Nanjing 210037, PR China 10.3762/bjoc.21.100 Abstract In recent years, amidyl radicals have emerged as highly efficient and versatile reagents for hydrogen atom

• the concurrent generation of the carbon cation 55. This cation was subsequently trapped by a nucleophile, leading to the formation of product 54. This system demonstrated a broad applicability for the general nucleophilic amination of benzylic C–H bonds. The substrate's scope and selectivity were

• it into the byproduct 46 and generating a carbon-centered radical 62. Species 62 is trapped by heteroarene 60, leading to the formation of the intermediate 63. This intermediate 63 undergoes SET and proton transfer with the assistance of O-anion 64 and the Br-5CzBN+• radical cation, delivering the

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• has sparked a continuously growing interest in synthesis of new carbon-rich unsaturated molecules and materials [1]. Graphene is a revolutionary material with exceptional properties, driving advancements across various scientific, industrial, and technological fields like organic electronics [2

• nonlinear optics (NLO) [20]. Furthermore, azulene subunits are present in many hypothetical allotropic two-dimensional carbon allotropes. In recent years many 2D graphenoid allotropic forms of carbon were theoretically predicted like a family based on the azulenoid kekulene [21], phagraphene (Figure 2a) [22

• ], TPH-graphene (Figure 2b) [23], PHH-graphene [24] and ψ-graphene [25]. Notably, fragments phagraphene and TPH-graphene have already been synthesized via on-surface chemistry and characterized using low-temperature scanning probe microscopy with CO-functionalized tips [23]. These non-alternant carbon

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

• years, particularly in the domain of oxidative radical difunctionalization reactions employing carbon radical reagents. This approach provides a powerful and versatile strategy for the concurrent introduction of two distinct functional groups across the double bond of N-arylacrylamides, facilitating the

• rapid construction of complex molecular architectures. This review aims to summarize the diverse strategies for inducing intramolecular transformations of N-arylacrylamides using various carbon radical reagents, including methods initiated by photonic, thermal, or electrochemical processes, which have

• been extensively investigated by researchers. Keywords: carbon radical reagents; intramolecular transformations; N-arylacrylamides; oxidative difunctionalization; radical reactions; Introduction Alkenes, as abundant and versatile feedstocks, have been widely employed in organic synthesis

Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers

• Kenichi Kato,
• Tatsuki Hiroi,
• Seina Okada,
• Shunsuke Ohtani and
• Tomoki Ogoshi

Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95

• followed by acid-mediated condensation. The linear copolymers show good solubility and carbon dioxide adsorption. Keywords: alternating copolymer; building block; formylation; gas adsorption; propellane; Introduction Combination of sp2- and sp3-hybridized atoms in core π-skeletons [1][2][3] is a key to

• % yield. Alcohol products, [4.3.3]_CH2OH and [3.3.3]_CH2OH, were then tested in acidic conditions using anhydrous FeCl3 as a Lewis acid. After the reactions, the alcohol proton signals at 1.54–1.58 ppm disappeared in the 1H NMR spectra, and aliphatic carbon ones at 63.1–63.2 ppm were largely up-field

Enhancing chemical synthesis planning: automated quantum mechanics-based regioselectivity prediction for C–H activation with directing groups

• Julius Seumer,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2025, 21, 1171–1182, doi:10.3762/bjoc.21.94

• Julius Seumer Nicolai Ree Jan H. Jensen Department of Chemistry, University of Copenhagen, Copenhagen, Denmark 10.3762/bjoc.21.94 Abstract The mild and selective functionalization of carbon–hydrogen (C–H) bonds remains a pivotal challenge in organic synthesis, crucial for developing complex

• carbon–hydrogen (C–H) bonds represent a fundamental challenge in modern organic chemistry, particularly because of the inherent stability and prevalence of these bonds in organic molecules. These bonds, which typically exhibit bond energies ranging from 90 to 110 kcal·mol−1, constitute the majority of

• activation, transforming these inert bonds into reactive carbon–transition metal (C–M) bonds. Subsequent transformations of these complexes enable the formation of an array of new functional groups, such as carbon–carbon and carbon–heteroatom bonds, underpinning a plethora of synthetic applications

Synthetic approach to borrelidin fragments: focus on key intermediates

• Yudhi Dwi Kurniawan,
• Zetryana Puteri Tachrim,
• Teni Ernawati,
• Faris Hermawan,
• Ima Nurasiyah and
• Muhammad Alfin Sulmantara

Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91

• . Intermediate 25 was prepared through TBDMS protection and desulfonylation of 24, itself derived from the condensation of epoxide 23b and sulfone 27. The precursor 27 was synthesized from Roche ester 29 via a sequence of steps, including reduction, three-carbon homologation, and enzymatic desymmetrization. An

• constructing Omura’s C1–C11 fragment Yadav and Yadav, in 2013, reported their work on preparing the C1–C11 fragment 61 of borrelidin. Their approach employed an iterative sequence of oxidation, Wittig olefination, hydrogenation, and asymmetric methylation for carbon homologation, alongside Sharpless

• ’ amide, and asymmetric methylation. Intermediate 65, in turn, would be obtained from the known five-carbon precursor 66 through the iterative sequence of oxidation, Wittig olefination, hydrogenation, asymmetric methylation, followed by reduction of the carboxyl group and protection of the resulting

Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• α-CD and cyanoaurate A commonly used step in cyanide leaching is to pass gold-bearing cyanide solutions through activated carbon beds to help concentrate the gold. Following this step, the gold that adsorbed onto carbon is removed either by aggressive solutions (cyanide or hydroxide leaching), or by

• processes with high energetic costs such as heating or applying high pressure. Seeking to find an eco-friendlier method to strip the gold from carbon, the Stoddart group investigated the use of α-CD in a series of tests at the laboratory scale in which suspensions of KAu(CN)2-loaded carbon (50 mg

• silver in solution showed that not only the striping process was quite selective for gold, but also that the presence of silver helps to increase the yield of gold extraction to 31% (with 10% α-CD). This result was attributed to a competing effect of KAg(CN)2 on the carbon surface that promoted the

A versatile route towards 6-arylpipecolic acids

• Erich Gebel,
• Cornelia Göcke,
• Carolin Gruner and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88

• , heterogeneous catalytic hydrogenation of the enamine with palladium on carbon was chosen. While the hydride reduction of the acyliminium intermediate gave a nearly 1:1 diastereomer ratio, a 9:1 ratio was obtained for the catalytic hydrogenation (Scheme 4). While the hydride reduction of the N-acyliminium

• species did not show any significant diastereofacial discrimination, the catalytic hydrogenation occurs stereospecifically, particularly in the case of hydrogenation with palladium on carbon [49][50][51][52]. In this case, we propose that the restraints exerted by the first stereocenter lead to a

• kinetically controlled diastereofacial selectivity. The resulting diastereomers are separable by chromatography. 1H NMR was used to assign the configuration of the 2 diastereomers [53][54][55]. Carbon C2 is R-configured, as ᴅ-2-aminoadipic acid (1) was employed as the starting material. The minor diastereomer

Supramolecular assembly of hypervalent iodine macrocycles and alkali metals

• Krishna Pandey,
• Lucas X. Orton,
• Grayson Venus,
• Waseem A. Hussain,
• Toby Woods,
• Lichang Wang and
• Kyle N. Plunkett

Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87

• Supporting Information File 1, Figure S1). In addition, the crystal structure also demonstrates that the three iodine atoms, three carbonyl carbon atoms and six oxygen atoms circumscribe a small bowl-like cavity within the macrocycle. With the consideration of all primary and secondary bonds, the small

• macrocycle’s cavity, we considered the charge distribution on three iodine atoms, three carbonyl carbon atoms and six oxygen atoms that constitute a small cavity within the macrocycle. The Mulliken charge distribution diagram of HIM 1 (Figure 3, middle) shows that the summation of the overall charge on three

• curcumscribe the small cyclic core represented by blue color. Three carbonyl amides project outward. B) DFT image of 1 displaying the distribution of Mulliken charges on iodine (purple), oxygen (red), and carbon (grey); benzyl groups are ommited for clarity. C) Calculated electrostatic potential map showing