Synthesis of (macro)heterocycles by consecutive/repetitive isocyanide-based multicomponent reactions

• Angélica de Fátima S. Barreto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2019, 15, 906–930, doi:10.3762/bjoc.15.88

• diastereomers. After converting 68 into aldehyde 69, this was reacted with cyclopropyl isocyanide 57 and acetic acid (Passerini reaction) furnishing compound 70, which was converted to telaprevir (64) in three additional steps. Macrocyclic peptoid synthesis Dömling et al. performed the combination of two

• bifunctional compounds 74 at the end, allowing the obtention of the 16- to 20-membered tetrazolic macrocycles 75 in only five steps (Scheme 14). A similar approach was used shortly afterwards by the same research group in the synthesis of macrocyclic depsipeptides containing a tetrazole nucleus [31]. The

• combination of two isocyanide-based multicomponent reactions (azido-Ugi and Passerini reactions) allowed easy access to a library of macrocyclic depsipeptides in only four steps with variations in the size of the macrocycle as well as in the side chains (Scheme 15). This was the first example in which the

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• –acceptor [2]rotaxanes such as 19 through liquid-assisted mechanochemical milling (Figure 9). The donor–acceptor interaction between the electron-deficient naphthalene diimide moiety and the electron-rich naphthalene moieties embedded in the macrocyclic polyethers played the vital role for the construction

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

• represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, L' is an azobenzene carboxylate co-ligand, and M = Cd(II), Ni(II) or Zn(II), is reported. A series of new complexes were synthesized, namely [M2L(μ-L')]+ (L' = azo-H, M = Cd (1), Ni (2); L' = azo-OH, M = Zn (3), Ni (4); L' = azo-NMe2, M

• with λ = 365 nm reveals a photoisomerization of the co-ligand from the trans to the cis form. Keywords: azobenzene carboxylates; cadmium; complexes; macrocyclic ligands; nickel; zinc; Introduction The macrocyclic N6S2 donor ligand H2L is an effective dinucleating ligand that supports a large number

• '. The co-ligand binds again via its carboxylato function in a μ1,3-bridging mode to give a Zn···Zn distance of 3.440 Å, which is typical for carboxylato-bridged Zn complexes supported by the macrocyclic N6S2 donor ligand. The average Zn–S, Zn–N and Zn–O distances are at 2.536 Å, 2.305 Å, and 2.049 Å

Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: toward the emergence of new building blocks

• Clémence Moitessier,
• Ahmad Rifai,
• Pierre-Edouard Danjou,
• Isabelle Mallard and
• Francine Cazier-Dennin

Beilstein J. Org. Chem. 2019, 15, 721–726, doi:10.3762/bjoc.15.67

• ], thioether macrocycles [11], macrocyclic Schiff bases [12] or even poly(phthalaldehyde) polymers [13]; taking into account that few studies were carried out with modified OPA on position 3 or 4. This could probably be due to the fact that the synthesis of 4-substituted OPA was, to the best of our knowledge

Design, synthesis and spectroscopic properties of crown ether-capped dibenzotetraaza[14]annulenes

• Krzysztof M. Zwoliński and
• Julita Eilmes

Beilstein J. Org. Chem. 2019, 15, 617–622, doi:10.3762/bjoc.15.57

• Krzysztof M. Zwolinski Julita Eilmes Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland 10.3762/bjoc.15.57 Abstract The first crown ether-capped dibenzotetraaza[14]annulenes (DBTAAs), featuring two macrocyclic binding sites fixed in a face-to-face orientation

• ], little research has been undertaken regarding DBTAAs functionalized with crown ether moieties (see Figure 1). Kruse and Breitmaier [24] reported annulated DBTAA‘s containing benzo-15-crown-5 scaffolds fused with benzenoid rings of the macrocyclic core. Both nickel(II) and cobalt(II) complexes were

• showed cation and solvent-induced dimerisation. More recently, Raston et al. reported the synthesis of Goedken’s macrocycle tmtaa nickel(II) complex featuring a single oligo(ethylene glycol) chain strapped across the face of the DBTAA macrocyclic core [28]. However, to the best of our knowledge, there

Synthesis and SAR of the antistaphylococcal natural product nematophin from Xenorhabdus nematophila

• Frank Wesche,
• Hélène Adihou,
• Thomas A. Wichelhaus and
• Helge B. Bode

Beilstein J. Org. Chem. 2019, 15, 535–541, doi:10.3762/bjoc.15.47

• moiety itself are required for bioactivity [16]. These findings suggest a specific interaction of this electrophilic moiety with a nucleophile. Such an interaction was previously reported for the macrocyclic peptide cyclotheonamide A, isolated from marine sponge Theonella sp. Cyclotheonamide A is

Selectivity in multiple multicomponent reactions: types and synthetic applications

• Ouldouz Ghashghaei,
• Francesca Seghetti and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2019, 15, 521–534, doi:10.3762/bjoc.15.46

• interesting case, where this principle does not apply, is introduced by Wessjohann [5][18], who introduced a family of MMCRs leading to complex macrocyclic structures instead of linear polymer chains. In these examples, a low concentration together with the use of specific substrates tune the reactivity

• pattern, promoting intramolecular interactions over intermolecular polymerizations. Thus, the use of the right conditions and the intelligent choice of the polyfunctionalized building blocks, enable an “architectural approach” towards the MMCR synthesis of macrocyclic adducts [19]. This multiple

• [21], supramolecular structures (cryptands, cages, cryptophanes, podands, etc.) [22][23][24], cyclic/macrocyclic peptides [25] and other complex structures in a straightforward manner (Scheme 5). The diversity in these systems arises not only from combining a variety of building blocks (from simple

Design of indole- and MCR-based macrocycles as p53-MDM2 antagonists

• Constantinos G. Neochoritis,
• Maryam Kazemi Miraki,
• Eman M. M. Abdelraheem,
• Ewa Surmiak,
• Tryfon Zarganes-Tzitzikas,
• Beata Łabuzek,
• Tad A. Holak and
• Alexander Dömling

Beilstein J. Org. Chem. 2019, 15, 513–520, doi:10.3762/bjoc.15.45

• ring. It is estimated that 3% of the known natural products consists of a macrocyclic ring [1][2][3][4][5]. Compared to macrocycles in synthetic molecules, the aforementioned occurrence is still over proportional; for that reason, these compounds have delighted scientists worldwide due to their special

• physicochemical properties, their roles in biological systems and the associated synthetic challenges [6][7]. However, only few synthetic methods allow for the convergent and fast access to a large macrocyclic chemical space [8][9][10]; most of the times their synthesis is complex, multistep and sequential [11

• MDM2–p53 interaction could enable p53 and reverse tumor formation [26][27][28]. Based on our knowledge to antagonize the oncogenic protein–protein interaction p53–MDM2 [23][29][30][31][32][33][34][35][36][37][38][39][40] we designed macrocyclic inhibitors in continuation of our previous work [13][23

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

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• -substituted NB with poly(ethylene glycol) (PEG) [69]. Ring-opening metathesis copolymerization of the rather strained cyclooctene (COE) and a strainless 27-membered macrocyclic olefin (MCO) led to the multiblock copolymer consisting of octenylene blocks linked with ring-opened MCO segments (Scheme 6) [70

First synthesis of cryptands with sucrose scaffold

• Patrycja Sokołowska,
• Michał Kowalski and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2019, 15, 210–217, doi:10.3762/bjoc.15.20

• ’,4,4’-penta-O-benzylsucrose and 1’,2,3,3’,4,4’-hexa-O-benzylsucrose. Keywords: cryptands; macrocyclization; sucrose; Introduction The design and synthesis of macrocyclic receptors is one of the main challenges of supramolecular chemistry [1][2]. These artificial systems exhibit interesting properties

• ]. There are also reports on the preparation of ‘distorted’ cyclodextrins in which diverse fragments are incorporated into the original oligosaccharide ring(s) [5]. Another class of sugar receptors is represented by macrocyclic derivatives with the carbohydrate unit being a part of a crown or aza-crown

• sucrose scaffold (e.g., 4) can be also prepared successfully [15][16]. All macrocyclic derivatives, shown in Figure 1, were prepared from hexa-O-benzylsucrose 3 by a connection of the terminal positions of glucose (C6) and fructose (C6’) units. Results and Discussion Diol 3 may be also used as a starting

A tutorial review of stereoretentive olefin metathesis based on ruthenium dithiolate catalysts

• Daniel S. Müller,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2018, 14, 2999–3010, doi:10.3762/bjoc.14.279

• higher catalyst loading (10.0–12.5 mol %) [21]. Macrocyclic ring-closing metathesis (RCM) with (Z)-butene (Z-25) was also studied affording 14–21-membered macrocycles (e.g., 38) in good yield and high stereoretention (Scheme 6b). More recently Hoveyda disclosed his findings concerning the synthesis of Z

Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

• investigated. Keywords: azulene; calixarenes; calixazulenes; supramolecular chemistry; tetraalkylammonium salts; Introduction Among the great variety of synthetic macrocyclic molecular receptors which have been reported, those that are referred to by their generic name “calixarene” loom large [1][2][3]. The

Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps

• Sambasivarao Kotha,
• Milind Meshram and
• Chandravathi Chakkapalli

Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223

• %). Subsequently, hydrogenation of compounds 126 and 125 was accomplished with H2 under Pd/C catalysis conditions to afford the respective saturated macrocyclic products 127 (80%) and 128 (90%). Since the small ring cyclophane is highly strained, compound 125 was formed as a minor product (Scheme 19). Recently, Li

• derivative 134 was realized in the presence of a Pd(OAc)2 catalyst with the aid of the ligand cataCXium A (135) to generate the macrocyclic product 136. Eventually, synthesis of MK-6325 (141) was achieved by adopting saponification followed by amidation (Scheme 20). Conclusion In this review, we have

Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• macrocyclic systems [18][19][20][21][22][23][24][25]. DNA mimics with triazole linkages were constructed [26][27]. The click reaction was used to generate a cyclic ADP-ribose second messenger mimic [28]. Modelling studies using MM+ energy minimization showed that pyrimidine nucleosides are useful synthons for

• (version 6.3) [50]. It is apparent that the 2’-deoxyribofuranosyl moiety of the open chain and the macrocyclic nucleosides favor an S-type sugar puckering with values of 70% S for azido-dU 7 and 68% for azido-dC 2. The values for the cyclic derivatives 8 and 4 are in the same range with 72% S-type pucker

Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis

• Tobias Fiedler,
• Michał Barbasiewicz,
• Michael Stollenz and
• John A. Gladysz

Beilstein J. Org. Chem. 2018, 14, 2354–2365, doi:10.3762/bjoc.14.211

• metatheses to give, after hydrogenations, metal complexes of in,in isomers of macrocyclic dibridgehead diphosphines [1][2][3][4][5][6][7][8][9][10][11][12][13]. Representative examples with square planar complexes are shown in Scheme 1. Analogous sequences with trigonal bipyramidal substrates proceed in

• related species. However, as described in the discussion section, the yields have not been competitive [25]. Another preliminary point concerns the ability of macrocyclic dibridgehead diphosphorus compounds to exhibit in/out isomerism [26]. As shown in Scheme 1, there are three limiting configurations for

• from metatheses of alkenyl groups on the same phosphorus atom – such as 17 (comparable to 6·2BH3) – appear to form in much smaller amounts. To our knowledge, only one macrocyclic dibridgehead diphosphine diborane has been previously reported, (in,in/out,out)-18·2BH3 in Scheme 9 [50][51]. This features

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

• relative insecticidal activities have also been reported [5][6]. Since 1990, there are two generations of commercial products of spinosyns (spinosad) and spinetoram (Figure 1). Structurally, spinosad and spinetoram are both composed of D-forosamine and rhamnose coupled to a macrocyclic tetracycle. Spinosad

Synthesis of a water-soluble 2,2′-biphen[4]arene and its efficient complexation and sensitive fluorescence enhancement towards palmatine and berberine

• Xiayang Huang,
• Xinghua Zhang,
• Tianxin Qian,
• Junwei Ma,
• Lei Cui and
• Chunju Li

Beilstein J. Org. Chem. 2018, 14, 2236–2241, doi:10.3762/bjoc.14.198

• the blood stream, but also be effectively dis-assembled in the acidic tumor environment, and thus improve the anticancer activity of oxaliplatin in vivo. In 2015, we introduced a new class of macrocyclic arenes, 4,4’-biphen[n]arenes (n = 3,4) with 4,4’-biphenol or 4,4’-biphenol ether monomers linked

A switchable [2]rotaxane with two active alkenyl groups

• Xiu-Li Zheng,
• Rong-Rong Tao,
• Rui-Rui Gu,
• Wen-Zhi Wang and
• Da-Hui Qu

Beilstein J. Org. Chem. 2018, 14, 2074–2081, doi:10.3762/bjoc.14.181

• the presence of Grubbs’ catalyst and thiol groups irradiated by UV light. Besides, the shuttling movement of the DB24C8 macrocyclic ring was confirmed by 1H NMR spectroscopy. Results and Discussion The structures of the two states of [2]rotaxane R1 are shown in Scheme 1. In the target structure [2

• station when the DBA site is deprotonated by external base. Besides, in the structure, one side of the chain is terminated by a bulky stopper bearing three long alkyl chains to prevent the macrocyclic moiety from slipping out the thread. Meanwhile, the long alkyl chains make it easy to form gels when the

• alkenyl units are reacted to generate polymers. On the other side, a naked alkenyl bond is introduced in the para position of the aromatic stopper. In the presence of external acid–base stimuli, the macrocyclic ring could be driven back and forth along the linear thread. Deprotonation of the DBA site by

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• -trifluoromethylamines, which are attractive due to their low basicity, ability to act as amide bioisosteres [42] and higher metabolic stability. The number of medicinal chemists who specialise in peptides has been increasing in recent years. This is largely due to the increasing interest in macrocyclic peptides. A key

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• comparison with ADP and ATP [11]. Another polyammonium receptor synthesized by Mascaros et al. [12] showed selective recognition of ADP in the presence of ATP in water. Undoubtedly, macrocyclic receptors have a number of advantages in the design of molecular receptors, providing preorganization of the

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• transfer; supramolecular chemistry; Introduction Cucurbit[n]urils (CBn, n = 5–8, 10, and 14) are a class of macrocyclic host molecules which are water soluble, nontoxic, and are able to bind a large variety of neutral and cationic guests in their inner cavity with high affinity [1][2][3][4]. This unique

• macrocyclic hosts and dyes that have so far been reported [16] are only of limited use for these currently emerging life science applications of CBs. Many of the fluorescent dyes which bind to CBs with significant fluorescence changes have a limited photostability, in particular under intense laser light

• of the dyes increased upon addition of CB7 (Figure 3). This result is in accordance with the anticipated anchor group mechanism leading to a complexation-induced protonation of the dye (Figure 1). It also suggests that the BODIPY core is not encapsulated in the macrocyclic cavity and that

An amphiphilic pseudo[1]catenane: neutral guest-induced clouding point change

• Tomoki Ogoshi,
• Tomohiro Akutsu and
• Tada-aki Yamagishi

Beilstein J. Org. Chem. 2018, 14, 1937–1943, doi:10.3762/bjoc.14.167

• , which exhibits a clouding point around 32 °C [1][2][3][4]. Recently, thermo-responsive molecules with additional functions have been developed to replace pNIPAAm [5][6][7][8][9][10]. For example, we have developed thermo-responsive macrocyclic molecules which exhibit LCST behavior regulated by host

• –guest chemistry [5][6][7]. The molecules consist of a non-ionic amphiphilic part containing tri(ethylene oxide) moieties, and a hydrophobic part consisting of a pillar[n]arene core (Figure 1a; 1, n = 5; 2, n = 6). Pillar[n]arenes, which were first reported by our group [11], were used as the macrocyclic

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• in color (yellow/colorless) for [1FDB24C8]2+ or a fluorescence change (OFF/ON) for [1ADB24C8]2+; see Figure 1. In addition, we have also previously prepared a [3]catenane containing two dibenzo[24]crown ether DB24C8 rings interlocked onto a much larger macrocyclic ring containing two 1,2-bis

Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives

• Zheng-Yi Li,
• Hong-Xiao Tong,
• Yuan Chen,
• Hong-Kui Su,
• Tangxin Xiao,
• Xiao-Qiang Sun and
• Leyong Wang

Beilstein J. Org. Chem. 2018, 14, 1901–1907, doi:10.3762/bjoc.14.164

• and yields of the Michael reactions. Supramolecular catalysis has drawn tremendous interest in the past few years [15][16][17][18][19][20][21][22][23]. In this context, calixarenes are ideal supramolecular macrocyclic scaffolds for the design of molecular receptors and organocatalysts due to their