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

Strong binding and fluorescence sensing of bisphosphonates by guanidinium-modified calix[5]arene

• Jie Gao,
• Zhe Zheng,
• Lin Shi,
• Si-Qi Wu,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2018, 14, 1840–1845, doi:10.3762/bjoc.14.157

• BPs in buffer solution, and more importantly, in artificial urine. Calibration lines were therefore set up in untreated artificial urine, allowing for quantifying the concentrations of BPs in the biologically relevant low range. Keywords: bisphosphonate; calixarene; fluorescence sensing; macrocyclic

• particularly suitable for the detection of analytes lacking chromophores. The key factor in IDA is the rational design of artificial receptors that are capable of binding analytes strongly and specifically. Calixarenes are the third generation of macrocyclic receptors after crown ethers and cyclodextrins. Due

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

• Rakesh Puttreddy,
• Ngong Kodiah Beyeh,
• S. Maryamdokht Taimoory,
• Daniel Meister,
• John F. Trant and
• Kari Rissanen

Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

• , aiding in the binding of polar guests such as N-oxides. Keywords: aromatic N-oxides; C–H···π Interactions; ditopic receptors; endo/exo complexation; host–guest chemistry; resorcinarenes; Introduction Resorcinarenes are macrocyclic compounds with a bowl-shaped cavity stabilised by circular

Synthesis of diamido-bridged bis-pillar[5]arenes and tris-pillar[5]arenes for construction of unique [1]rotaxanes and bis-[1]rotaxanes

• Ying Han,
• Li-Ming Xu,
• Cui-Yun Nie,
• Shuo Jiang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2018, 14, 1660–1667, doi:10.3762/bjoc.14.142

• ]rotaxane and [1]rotaxane are one of particular supramolecular assembly system and are considered as an important building block in the construction of diverse MIMs [5][6][7][8][9][10]. [1]Rotaxane has a macrocyclic wheel component connected with a self-locked chain axle, and a bulky stopper at the terminal

• ], cyclodextrin [24][25][26], calixarene [27][28][29] and pillararene have been successfully employed as the wheel subcomponent. Pillararenes are new star macrocyclic compounds with aromatic rings para-bridged by methylene units and have unique tubular shape rather than cone [30][31][32]. In recent years, an

A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene

• Liu-Pan Yang,
• Song-Bo Lu,
• Arto Valkonen,
• Fangfang Pan,
• Kari Rissanen and
• Wei Jiang

Beilstein J. Org. Chem. 2018, 14, 1570–1577, doi:10.3762/bjoc.14.134

• binding behavior of ZB4 and lays the basis for the construction of stimuli-responsive materials with ZB4 as a major component. Keywords: conformations; host–guest chemistry; macrocycles; supramolecular chemistry; zorb[4]arene; Introduction Macrocyclic receptors are the principal workhorses used in

• [15][16] and signal transduction [17] observed with bioreceptors. However, similar conformationally adaptive synthetic macrocyclic receptors are relatively rare in the literature [18][19][20][21][22][23]. During the last five years, we have developed two classes of macrocyclic receptors with

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

• either bis(1,2,3-triazolylphenyl) [86] or bis(1,2,4-triazolylphenyl) ligands [87]. Examples of the former class, namely complexes 39 and 40, are displayed in Figure 18. In particular, these complexes were designed to reduce excited-state distortions by bearing a macrocyclic chelating ligand and either

• ether, methylene or carbonyl bridging units. The derivatives showed bright blue phosphorescence centred at λem ca. 448–470 nm depending on the bridging unit. Such blue emission was retained when the complexes were embedded in PMMA rigid matrix. Interestingly, macrocyclic derivatives possessed higher

• PLQY in solution with values of 0.58–0.62 when compared to non-macrocyclic counterparts that was attributed to the enhanced structural rigidity imposed by the cyclic structure. By employing complex 39 as emissive material OLED devices with the following architecture were fabricated: ITO/NPB (50 nm)/mCP

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• calixarene; organocatalyst; supramolecular catalyst; Introduction The catalysis of organic reactions by macrocyclic host compounds is a longstanding proposed application of supramolecular chemistry and utilizes the use of noncovalent interactions in catalytic systems to achieve higher reaction rates, more

• 48 with nitroalkenes 49 (Scheme 13). The asymmetric Michael addition in the presence of 10–15 mol % of the macrocyclic catalysts 47a/47b afforded both enantiomers of the products 50 in high yields (up to 95%) and in high to excellent enantioselectivities (up to 99% ee). In order to confirm the role

London dispersion as important factor for the stabilization of (Z)-azobenzenes in the presence of hydrogen bonding

• Andreas H. Heindl,
• Raffael C. Wende and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2018, 14, 1238–1243, doi:10.3762/bjoc.14.106

• can be reversed by the incorporation of azobenzene units in macrocyclic arrangements [15]. For example, the groups of Tamaoki [16] and Herges [17] reported azobenzophanes that isomerize thermally to their energetically lower Z-conformations from their corresponding higher energy E-isomers. Moreover

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

• ][18][19][20][21][22][23] (isolated from the heartwood and essential oils of trees of the family Cupressaceae), to complex macrocyclic analogues, such as harringtonolide (5) [24][25][26], which was found to have antineoplastic and antiviral properties, and caulersin (6) [26], which is a biologically

Iodine(III)-mediated halogenations of acyclic monoterpenoids

• Laure Peilleron,
• Tatyana D. Grayfer,
• Joëlle Dubois,
• Robert H. Dodd and
• Kevin Cariou

Beilstein J. Org. Chem. 2018, 14, 1103–1111, doi:10.3762/bjoc.14.96

• of molecular scaffolds, from the mono-chlorinated linear chain of fallachromenoic acid [2], to the pentahalogenated halomon skeleton [3] and encompassing many intricate polycyclic and macrocyclic structures with complex vicinal oxygen/halogen patterns, such as bromophycolide B [4] and dichotellide B

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• interactions play a crucial role in its binding to DNA groove. Similarly, the same group recently reported a macrocyclic copper(II) complex, ([CuL(ClO4)2] where L is 1,3,6,10,12,15-hexaazatricyclo[13.3.1.16,10]eicosane) and studied its interaction with calf thymus DNA (ct-DNA). It was confirmed that the Cu(II

Preparation, structure, and reactivity of bicyclic benziodazole: a new hypervalent iodine heterocycle

• Akira Yoshimura,
• Michael T. Shea,
• Cody L. Makitalo,
• Melissa E. Jarvi,
• Gregory T. Rohde,
• Akio Saito,
• Mekhman S. Yusubov and
• Viktor V. Zhdankin

Beilstein J. Org. Chem. 2018, 14, 1016–1020, doi:10.3762/bjoc.14.87

• preparation of several bicyclic benziodoxoles 3 starting from 2-iodoisophthalic acid (2, Scheme 1b). These bicyclic benziodoxoles 3 can be used as efficient coupling reagents for the direct condensation reaction between carboxylic acids and alcohols or amines to provide esters, macrocyclic lactones, or amides