Catalytic asymmetric formal synthesis of beraprost

• Yusuke Kobayashi,
• Ryuta Kuramoto and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2015, 11, 2654–2660, doi:10.3762/bjoc.11.285

• nucleophile and relatively unreactive Michael acceptors [27][28][29][30][31][32][33]. We envisioned that our recently developed powerful hydrogen bond (HB)-donor bifunctional organocatalyst [33] could promote the desired reaction of 7 or 8, which can be synthesized from commercial sources 9 or 10. Overall

Organocatalytic and enantioselective Michael reaction between α-nitroesters and nitroalkenes. Syn/anti-selectivity control using catalysts with the same absolute backbone chirality

• Jose I. Martínez,
• Uxue Uria,
• Maria Muñiz,
• Efraím Reyes,
• Luisa Carrillo and
• Jose L. Vicario

Beilstein J. Org. Chem. 2015, 11, 2577–2583, doi:10.3762/bjoc.11.277

• general for a variety of nitroalkene Michael acceptors and nitroacetate donors. For this reason, we initially studied the reaction using squaramide 4 as catalyst that leads to the formation of syn-3 adducts. In this sense, and as it can be seen in Table 1, the reaction performed excellently in almost all

• the cases studied. In particular, when the reaction was conducted using nitrostyrene derivatives as Michael acceptors, the corresponding adducts 3a–k were isolated cleanly, in high yields, diastereo- and enantioselectivities regardless the electronic nature of the aromatic substituent of the

Copper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors

• Thibault E. Schmid,
• Sammy Drissi-Amraoui,
• Christophe Crévisy,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263

• Chimie, 8 Rue de l’Ecole Normale, 34296 Montpellier Cedex 5, France 10.3762/bjoc.11.263 Abstract The copper-catalyzed asymmetric conjugate addition (ACA) of nucleophiles onto polyenic Michael acceptors represents an attractive and powerful methodology for the synthesis of relevant chiral molecules, as

• it enables in a straightforward manner the sequential generation of two or more stereogenic centers. In the last decade, various chiral copper-based catalysts were evaluated in combination with different nucleophiles and Michael acceptors, and have unambiguously demonstrated their usefulness in the

• control of the regio- and enantioselectivity of the addition. The aim of this review is to report recent breakthroughs achieved in this challenging field. Keywords: conjugate additions; electron-deficient alkenes; enantioselective catalysis; extended Michael acceptors; organometallic nucleophiles

Urethane tetrathiafulvalene derivatives: synthesis, self-assembly and electrochemical properties

• Xiang Sun,
• Guoqiao Lai,
• Zhifang Li,
• Yuwen Ma,
• Xiao Yuan,
• Yongjia Shen and
• Chengyun Wang

Beilstein J. Org. Chem. 2015, 11, 2343–2349, doi:10.3762/bjoc.11.255

• the fields of supramolecular and materials chemistry due to their great potential application in molecular electronics, for example, as switches and conductors [10][11][12][13][14]. As we all know, TTF derivatives can form charge transfer (CT) complexes with electron acceptors such as

Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines with aryl iodides

• Svetlana P. Panchenko,
• Alexei D. Averin,
• Maksim V. Anokhin,
• Olga A. Maloshitskaya and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2015, 11, 2297–2305, doi:10.3762/bjoc.11.250

• to the conditions of chromatographic isolation in each case. 4-Iodoanisole with a strong electron-donating substituent provided 56% yield of the diarylated compound 17 (Table 2, entry 5), while one could expect much lower reactivity of this compound compared to aryl iodides bearing acceptors

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

• Baiba Turovska,
• Henning Lund,
• Viesturs Lūsis,
• Anna Lielpētere,
• Edvards Liepiņš,
• Sergejs Beljakovs,
• Inguna Goba and
• Jānis Stradiņš

Beilstein J. Org. Chem. 2015, 11, 2166–2170, doi:10.3762/bjoc.11.234

• corresponding ground state species. The reaction between photochemically generated radical cations and radical anions by electron transfer from photoexcited electron donor to electron acceptors is often reversible [37] thus reproducing the reactant pair without the formation of a chemical bond. As the dioxygen

Conformational equilibrium in supramolecular chemistry: Dibutyltriuret case

• Karina Mroczyńska,
• Małgorzata Kaczorowska,
• Erkki Kolehmainen,
• Ireneusz Grubecki,
• Marek Pietrzak and
• Borys Ośmiałowski

Beilstein J. Org. Chem. 2015, 11, 2105–2116, doi:10.3762/bjoc.11.227

• interactions point of view the most efficient association exists in complexes in which all hydrogen bond donors belong to one molecule and all hydrogen bond acceptors to the other. The last condition was tested for quadruple hydrogen bonded associates [14], while the basis of this phenomenon are secondary

• to exist in linear form without any intramolecular HBs and stabilized by four intermolecular ones. In general the dibutyltriuret molecule carrying four hydrogen bond donors (D, red, Figure 2) and three hydrogen bond acceptors (A, blue) can exist in various conformations stabilized by one or two

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• hydrogen bonding acceptors. 1H NMR and fluorescence experiments in chloroform showed that this series of foldamers complexes primary and secondary alkyl ammonium products [39]. In most cases, we investigated the binding of foldamers for different guests in less polar chloroform. However, during the

• environments [46]. The high stability of the folded conformation of the 22 series also make them useful frameworks for creating a variety of complicated supramolecular architectures [42]. Although alkoxyl groups had been popularly used as acceptors for intramolecular hydrogen bonding [40][41][42], I was also

• approximately 1.8 nm in diameter [69]. At first we expected that this series of triazole foldamers would be good hydrogen bonding acceptors. Intriguingly, the foldamers did not exhibit observable binding affinity to saccharides or amide derivatives even in less polar chloroform. Liyan designed different

Chiral Cu(II)-catalyzed enantioselective β-borylation of α,β-unsaturated nitriles in water

• Lei Zhu,
• Taku Kitanosono,
• Pengyu Xu and
• Shū Kobayashi

Beilstein J. Org. Chem. 2015, 11, 2007–2011, doi:10.3762/bjoc.11.217

• catalysis, which has been reported recently for asymmetric boron conjugate addition, is characterized by the effective and thermodynamically stable catalysis in water. Furthermore, a broad range of α,β-unsaturated acceptors, including one example of an α,β-unsaturated nitrile, are applicable, and the

Engineering Pichia pastoris for improved NADH regeneration: A novel chassis strain for whole-cell catalysis

• Martina Geier,
• Christoph Brandner,
• Gernot A. Strohmeier,
• Mélanie Hall,
• Franz S. Hartner and
• Anton Glieder

Beilstein J. Org. Chem. 2015, 11, 1741–1748, doi:10.3762/bjoc.11.190

• cofactors as electron donors and acceptors. As these cofactors are required in stoichiometric amounts to drive the reaction to completion and the simple addition of these compounds is not acceptable from an economical point of view, efficient in situ regeneration of the consumed cofactor is required. During

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• , cyclic amines were produced. Carboxylic acids were particularly fruitful affording C-centered radicals that alkylated alkenes and took part in tandem addition cyclizations producing chromenopyrroles; decarboxylative homo-dimerizations were also observed. Acceptors initially yielding radical anions

• -affirmed as the best compromise. Reactions of aryloxyacetic acids functionalized with suitably sited alkene 24, aromatic or oxime ether acceptors, were carried out with P25 under standard conditions and also in sol–gel TiO2 coated NMR tubes (see Scheme 6). For styrenyl acids 24 control photolyses in the

• series of two electron reductions. The scope of reductive photoredox applications was significantly boosted by Scaiano and co-workers’ discovery that organic halides function as acceptors with platinized TiO2 nanoparticles [71]. They used (iPr)2NEt as the sacrificial donor and demonstrated that reductive

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

• Maroš Bella,
• Miroslav Koóš and
• Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

• unknown [7]. In general, GTs transfer sugar nucleotide donors onto suitable acceptors during the biosynthesis of glycans and glycoconjugates [8]. Both donor and acceptor substrates are recognized by GTs binding pockets. For instance, in the course of biosynthesis of complex and hybrid oligosaccharides

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F₄TCNQ

• Raúl García,
• M. Ángeles Herranz,
• Edmund Leary,
• M. Teresa González,
• Gabino Rubio Bollinger,
• Marius Bürkle,
• Linda A. Zotti,
• Yoshihiro Asai,
• Fabian Pauly,
• Juan Carlos Cuevas,
• Nicolás Agraït and
• Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

• the use of single molecules as chemical sensors, in which analyte molecules may bind to a backbone to alter its conductance. Further combinations of donors and acceptors should be explored in order to evaluate this potential. Depictions of 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene (exTTF

Donor–acceptor type co-crystals of arylthio-substituted tetrathiafulvalenes and fullerenes

• Xiaofeng Lu,
• Jibin Sun,
• Shangxi Zhang,
• Longfei Ma,
• Lei Liu,
• Hui Qi,
• Yongliang Shao and
• Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 1043–1051, doi:10.3762/bjoc.11.117

• , those involving fullerene molecules are of growing interest due to their potential application in organic voltaics [20]. The TTF–fullerene dyad is a typical donor–acceptor (D–A) system, where TTFs and fullerenes act as donors and acceptors, respectively. The TTF–fullerene dyad can be constructed by (1

Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

• Yunfei Wang and
• Yuming Zhao

Beilstein J. Org. Chem. 2015, 11, 957–965, doi:10.3762/bjoc.11.107

• materials and supramolecular assemblies [1][2][3][4][5], since the first discovery by Wudl and others in the early 1970s that TTF upon interactions with suitable electron acceptors could give rise to charge-transfer complexes exhibiting excellent metallic conductivity [6][7]. The remarkable electron

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• -energy bands to charge-transfer absorptions, which are usually observed in π-conjugated systems containing TTF donors and large acetylenic scaffolds that behave as electron acceptors [8][9][10]. The significant redshifts of the charge-transfer absorptions experienced for 8 and 2a relative to the

Copper ion salts of arylthiotetrathiafulvalenes: synthesis, structure diversity and magnetic properties

• Longfei Ma,
• Jibin Sun,
• Xiaofeng Lu,
• Shangxi Zhang,
• Hui Qi,
• Lei Liu,
• Yongliang Shao and
• Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 850–859, doi:10.3762/bjoc.11.95

• -based conducting materials are mainly produced as radical cation salts by electrochemical oxidation and CT complexes by chemical oxidation with electron acceptors [5][6]. Most Ar-S-TTFs possess redox potentials higher than that of bis(ethylenedithio)-TTF (BEDT-TTF) [33][34][35][36][37][38][39

• ]. Consequently, the complexes of Ar-S-TTFs with electron acceptors such as fullerenes [40][41] and TCNQ [42] show a neutral ground state. However, Ar-S-TTFs can be chemically oxidized by strong electron acceptors such as F4TCNQ [42] and Keggin-type phosphomolybdic acid [43] to form CT complexes. In comparison

Multivalency as a chemical organization and action principle

• Rainer Haag

Beilstein J. Org. Chem. 2015, 11, 848–849, doi:10.3762/bjoc.11.94

• , however, is completely different, when several covalently linked ligands of the same or of a similar nature bind to an ensemble of acceptors (multivalent interactions) [1]. Due to the multiple additive (in some cases cooperative) interactions the equilibrium will shift and bond reinforcement occurs

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• ligand. Since this publication, many groups have developed methods to conduct tandem conjugate addition–alkylations, allylations and aldol reactions [21]. Through the work of Alexakis, Feringa and others, the range of Michael acceptors used in both CA and tandem CA–α-functionalization reactions have been

• other Michael acceptors. In order to improve the reactivity of amides and lactams, they have been modified in the following manner: A) placing an EWG on the nitrogen [22], B) placing an EWG on the α-carbon atom [23], C) converting the amide/lactam to a thioamide/lactam or D) activation by a Lewis acid

• limited number of reviews focus on ACA reactions that are performed using α,β-unsaturated amides or lactams as Michael acceptors. In the many reviews that have been published on CA reactions, there are only a handful of examples provided where α,β-unsaturated amides or lactams are Michael acceptors. Since

3-Glucosylated 5-amino-1,2,4-oxadiazoles: synthesis and evaluation as glycogen phosphorylase inhibitors

• Marion Donnier-Maréchal,
• David Goyard,
• Vincent Folliard,
• Tibor Docsa,
• Pal Gergely,
• Jean-Pierre Praly and
• Sébastien Vidal

Beilstein J. Org. Chem. 2015, 11, 499–503, doi:10.3762/bjoc.11.56

• as aryl moieties, with 2-naphthyl identified as the best pharmacophore for the series discussed above (Figure 1, D–I). Nevertheless, hydrogen bonds might also be created in this secondary binding site with other residues. The introduction of hydrogen bond donors and/or acceptors at the 5-position of

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

• Patchornik [20]. As a complicating factor, unlike other side-chain derivatives of hydroxyamino acids, the O-acrylic derivatives are powerful acceptors for conjugate addition and must be kept strictly in salt form to avoid decomposition through self-addition. The problem is exacerbated in proline derivatives

Bis(vinylenedithio)tetrathiafulvalene analogues of BEDT-TTF

• Erdal Ertas,
• İlknur Demirtas and
• Turan Ozturk

Beilstein J. Org. Chem. 2015, 11, 403–415, doi:10.3762/bjoc.11.46

• with the discovery of the salt of 1 with 7,7,8,8-tetracyanoquinodimethane (2, TTF-TCNQ) in 1973 [4]. Since then, studies have been focused on the syntheses of donor TTF analogues and investigations of the physical properties of their charge-transfer (CT) salts with various acceptors for applications

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• the hydrogen transfer catalyzed by transition metal complexes. In these reactions, compounds with a double bond or a C–Hal bond act as oxidants (hydrogen acceptors). Examples of these reactions with aldehydes or primary alcohols as C–H reagents are given in Table 2. Crotononitrile, acetone, and benzyl

Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

• César A. Estévez,
• José Ramón Isasi,
• Eneko Larrañeta and
• Itziar Vélaz

Beilstein J. Org. Chem. 2014, 10, 3127–3135, doi:10.3762/bjoc.10.330

• group. When the galactosyl acceptor is water, a galactose molecule is produced and the hydrolysis of lactose occurs. However, this transfer can be performed onto other acceptors such as sugars, yielding oligosaccharides through a transglycosylation mechanism [5]. Hydrogels are 3D networks capable of

Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase

• María Emilia Cano,
• Rosalía Agusti,
• Alejandro J. Cagnoni,
• María Florencia Tesoriero,
• José Kovensky,
• María Laura Uhrig and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 3073–3086, doi:10.3762/bjoc.10.324

• transfer reaction from 3’-sialyllactose to the natural substrate N-acetyllactosamine, was also studied. Most of the substrates behaved as good acceptors and moderate competitive inhibitors. A di-N-lactoside showed to be the strongest competitive inhibitor among the compounds tested (70% inhibition at

• -galactopyranosides (βGalp) present in T. cruzi mucins play an important role in the interaction between the parasite and the host since they are the acceptors for sialic acid transferred by the unique trans-sialidase (TcTS) [7][8][9] from host cells instead of using a sialyltransferase and the donor nucleotide CMP

• -thiogalactopyranosides and their inhibitory activity against the β-galactosidase from E. coli [36][37]. The study of β-galactopyranosides as acceptor substrates for sialic acid is in general concomitant with the study of their inhibitory properties, as they usually behave as competitive acceptors. Thus, both aspects