Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

• Matthieu Jouffroy,
• Rafael Gramage-Doria,
• David Sémeril,
• Dominique Armspach,
• Dominique Matt,
• Werner Oberhauser and
• Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

• enantioselectivities probably arise from the embracing properties of the HUGPHOS ligands, which facilitates chirality transfer. Heck cross-coupling Phosphine-assisted Heck reactions strongly depend on the bulkiness of the phosphine used [64]. To assess HUGPHOS-2 in Heck coupling, we focused on the reaction between

• hydroformylation of styrene. In these systems, the high isoselectivity arises from the ligand ability to exclusively generate monophosphine complexes while the high enantioselectivity is a result of the efficient chirality transfer imposed by the embracing character of the chiral CD cavity. To the best of our

Oligomerization of optically active N-(4-hydroxyphenyl)mandelamide in the presence of β-cyclodextrin and the minor role of chirality

• Helmut Ritter,
• Antonia Stöhr and
• Philippe Favresse

Beilstein J. Org. Chem. 2014, 10, 2361–2366, doi:10.3762/bjoc.10.246

• spectroscopy. The magnetic interaction of the monomer with the cavity of RAMEB-CD is obvious in the 2D ROESY NMR spectra as shown in Figure 1 (marked areas). Principally, cyclodextrins and their derivatives are able to discriminate enantiomeric compounds [9][10]. Such chirality recognition is provable with 1H

• NMR spectroscopy because of the different induced shift of the protons which became diastereotopic through complexation [11][12]. Actually, the chirality discrimination of 1 with RAMEB-CD is evident from the different induced shift of the protons 8 at 5.2 ppm (zoomed out in Figure 1). The MALDI–TOF MS

De novo macrolide–glycolipid macrolactone hybrids: Synthesis, structure and antibiotic activity of carbohydrate-fused macrocycles

• Richard T. Desmond,
• Anniefer N. Magpusao,
• Chris Lorenc,
• Jeremy B. Alverson,
• Nigel Priestley and
• Mark W. Peczuh

Beilstein J. Org. Chem. 2014, 10, 2215–2221, doi:10.3762/bjoc.10.229

• backbone of the macrocycle whose chirality is dictated by the absolute configuration of the C4 stereogenic center. The topology is a defining feature of this family of [13]-macrodiolides. By virtue of the planar chirality, [13]-macrodiolides such as 3 have an axis of chirality associated with them. We were

• schematic representation. An axis of chirality associated with the topology of the macrocycle is indicated with a dashed line in b). Structures of 5 and 6 from X-ray crystallographic data; a) and b) side views of 5 (a) and 6 (b) with mean plane of macrocycle in blue and D-glucose in red; c) and d) views of

Molecular recognition of AT-DNA sequences by the induced CD pattern of dibenzotetraaza[14]annulene (DBTAA)–adenine derivatives

• Marijana Radić Stojković,
• Marko Škugor,
• Łukasz Dudek,
• Jarosław Grolik,
• Julita Eilmes and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2175–2185, doi:10.3762/bjoc.10.225

• ), whereas the isoelliptic points supported the formation of only one type of the compound/DNA or RNA complex. The intensity decrease of ds-DNA/RNA CD bands is usually associated with the partial disruption of the polynucleotide helical chirality caused by the binding of a small molecule. The reference

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

• elements, thereby providing suitable chirality, nucleophilicity, basicity, functionality, and rigidity. 2 Enantioselective reactions catalyzed by chiral phosphines Using the chiral phosphines described above as catalysts, a number of highly enantioselective reactions have been achieved, offering a wide

P(O)R₂-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

• Rong-Bin Hu,
• Hong-Li Wang,
• Hong-Yu Zhang,
• Heng Zhang,
• Yan-Na Ma and
• Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

• reported operation, the substrates of biaryl derivatives that contained phosphate with axial chirality were obtained in high yields using the Suzuki–Miyaura coupling reaction with the assistance of this versatile chiral ligand [31][32][33][34]. We used substituted naphthylboronic acid or ortho-substituted

• -phenylboronic acid to synthesize the corresponding substituted binaphthyl or phenyl-naphthyl skeleton substrates with axial chirality. To maintain the axial chirality within the substrates, a steric hindrance effect at the ortho position of phenylboronic acids was required, rendering the non-ortho substituted

Relay cross metathesis reactions of vinylphosphonates

• Raj K. Malla,
• Jeremy N. Ridenour and
• Christopher D. Spilling

Beilstein J. Org. Chem. 2014, 10, 1933–1941, doi:10.3762/bjoc.10.201

• complete chirality transfer. Various carbon, nitrogen, and oxygen nucleophiles participate in the palladium-catalyzed substitution reactions of phosphono allylic carbonates 1. Vinylphosphonates formed in this way, for example 2a–e (Figure 1), have been used in the synthesis of the natural products

Sacrolide A, a new antimicrobial and cytotoxic oxylipin macrolide from the edible cyanobacterium Aphanothece sacrum

• Naoya Oku,
• Miyako Matsumoto,
• Kohsuke Yonejima,
• Keijiroh Tansei and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2014, 10, 1808–1816, doi:10.3762/bjoc.10.190

• proton, not observed in the 1H spectrum, was assigned to a hydroxy proton (9-OH). Thus, the planar structure of 1 was determined to be a new 14-membered macrolide. The stereogenic center C13 constitutes an α-acyloxy ketone moiety and deacylation catalyzed by a base may result in the loss of chirality

• -configuration of C12 to the chirality of C13, 3 was treated with NaOMe in methanol, and the obtained product triol 4 was converted to acetonide 5. The conformation of the 2,2-dimethyl-1,3-dioxolane ring in 5 was analyzed by NOESY and HSQC experiments, both of which confirmed a trans relationship of H12 and H13

Rational design of cyclopropane-based chiral PHOX ligands for intermolecular asymmetric Heck reaction

• Marina Rubina,
• William M. Sherrill,
• Alexey Yu. Barkov and
• Michael Rubin

Beilstein J. Org. Chem. 2014, 10, 1536–1548, doi:10.3762/bjoc.10.158

• selectivity. Structural modification of the flat ortho-phenylene tether in the Pfaltz ligand through the incorporation of additional chirality elements into the ligand backbone allowed for significant improvement of the enantioselectivity. Thus, ferrocene-based ligands introduced by Dai and Hou [55][56], and

Why a diaminopyrrolic tripodal receptor binds mannosides in acetonitrile but not in water?

• Diogo Vila-Viçosa,
• Oscar Francesconi and
• Miguel Machuqueiro

Beilstein J. Org. Chem. 2014, 10, 1513–1523, doi:10.3762/bjoc.10.156

• simulations were performed using GROMACS 4.0.7 [43][44] and adapted parameters from the GROMOS 56ACARBO [45][46] force field. In all the constant protonation simulations, the neutral secondary amino groups were built in the R configuration. In the constant-pH MD simulations, the chirality of the amino groups

Asymmetric Ugi 3CR on isatin-derived ketimine: synthesis of chiral 3,3-disubstituted 3-aminooxindole derivatives

• Giordano Lesma,
• Fiorella Meneghetti,
• Alessandro Sacchetti,
• Mattia Stucchi and
• Alessandra Silvani

Beilstein J. Org. Chem. 2014, 10, 1383–1389, doi:10.3762/bjoc.10.141

• reaction of the glycine derivative 3f produced a complex inseparable mixture of products (Table 2, entry 11). When N-Boc-D-Pro was used as the acid component (Table 2, entry 10) a high 96:4 dr was measured despite a low yield (18%). This outcome suggests a matching/mismatching effect between the chirality

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• cyclic adducts exhibit recognition properties towards C60 in toluene solutions (up to log Ka = 3.2) with variable stoichiometries and variable intensities of the charge-tranfer band upon complexation. Keywords: BINOL; C60; carbon nanomaterials; carbon nanostructures; chirality; macrocycles; sensors

• ] macrocycles, induced CD activity in the characteristic UV–vis absorption bands of C60 showed how the chirality of the macrocyclic units could be transferred to the overall supramolecular ensemble [30]. In this paper, we extend on our previous studies by describing the synthesis of optically-active D2 and D3

Synthesis of a sucrose dimer with enone tether; a study on its functionalization

• Zbigniew Pakulski,
• Norbert Gajda,
• Magdalena Jawiczuk,
• Jadwiga Frelek,
• Piotr Cmoch and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2014, 10, 1246–1254, doi:10.3762/bjoc.10.124

• mixed with a chiral diol ligand forms complexes active in ECD in which a transfer of ligand chirality to the in situ-formed complex occurs in solution. Thus, stereochemistry of vic-diols can be easily assigned based on the helicity rule developed for this class of compounds. This rule correlates the

Atherton–Todd reaction: mechanism, scope and applications

• Stéphanie S. Le Corre,
• Mathieu Berchel,
• Hélène Couthon-Gourvès,
• Jean-Pierre Haelters and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117

• in favor of the addition of the nucleophilic amine on chlorophosphorinane as intermediate. All the studies reported above shed some light on the mechanism of the AT reaction. None of these studies, however, focused on the chirality at the phosphorus atom. The first investigation of the

• methanol. The use of 7-1 in the AT reaction in the presence of CCl4, tributylamine and aniline as a nucleophile produced 7-2 with full stereocontrol (note: due to the substitution of a hydrogen atom by an aniline moiety, the numbering used to determine the chirality at the phosphorus atom was changed

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

• Dominik Lenhart and
• Thorsten Bach

Beilstein J. Org. Chem. 2014, 10, 890–896, doi:10.3762/bjoc.10.86

• as a co-solvent [39] and that the diastereoselectivity depends both on the stereogenic center at C5 and on the chirality of the menthyl (Men) backbone [40]. In more recent work [41][42], Nishibayashi et al. showed that iridium complexes can serve as efficient PET catalysts for the addition of α

Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• ]. Compound 1 possesses bowl chirality [9][24][25] and the crystal represents a racemic mixture in which the two enantiomers are stacked in columns alternating at 4.0 Å intervals with side-to-side offsets (Figures 2e,f). In the herringbone arrangement of the pyrene moieties, the CH–π interactions occur at a

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• cyano end-capped bent-shaped materials it was documented [29][30][31] that reversing the position of hydroxylic and carboxylic groups exerts a profound effect on the mesophase properties. The bent-shaped molecules can create polar mesophases in spite of lack of molecular chirality. The most frequently

• antiferroelectric manner (SmCSPA and SmCAPA phases with a lower index A standing beneath P) and exhibit the synclinic (a lower index S standing beneath C) or anticlinic (a lower index A standing beneath C) molecular tilt in neighboring layers [1][33][34]. The structural chirality of subsequent layers, resulting

• with change of the structural chirality is detected more often [39][40][41]. Bent-shaped molecules rarely form a lamellar phase with a triclinic symmetry C1 called general tilt smectics, SmCG [42][43][44][45]. The molecules in the SmCG phase are tilted in such a way that the polarization vector has its

Synthesis of fluorescent (benzyloxycarbonylamino)(aryl)methylphosphonates

• Michał Górny vel Górniak,
• Anna Czernicka,
• Piotr Młynarz,
• Waldemar Balcerzak and
• Paweł Kafarski

Beilstein J. Org. Chem. 2014, 10, 741–745, doi:10.3762/bjoc.10.68

• without purification (Scheme 4). Upon halogen introduction a new chirality center is formed at the phosphorus atom and the products 5 and 6 were obtained as unequimolar mixtures of diastereoisomers (45:55 and 42:58 respectively). Upon reaction with an excess of aliphatic alcohol mixed esters of reversed

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• , aldehydes and alkenes in a three-component reaction based on the cascade imine formation, azomethine ylide generation and [3 + 2] cycloaddition reaction for the synthesis of pyrrolidines. However, the adopted method to induce chirality in the final products is rather dissimilar. Thus, in 2006 Garner’s group

Synthesis and stereochemical assignments of diastereomeric Ni(II) complexes of glycine Schiff base with (R)-2-(N-{2-[N-alkyl-N-(1-phenylethyl)amino]acetyl}amino)benzophenone; a case of configurationally stable stereogenic nitrogen

• Hiroki Moriwaki,
• Daniel Resch,
• Hengguang Li,
• Iwao Ojima,
• Ryosuke Takeda,
• José Luis Aceña and
• Vadim A. Soloshonok

Beilstein J. Org. Chem. 2014, 10, 442–448, doi:10.3762/bjoc.10.41

• preferences, were an important part of this work. Results and Discussion Taking advantage of the recently developed new generation of modular ligands/complexes 3 [73][74], we have designed ligands 4a–f (Scheme 1) derived from α-phenylethylamine [75][76], as the source of chirality. As one can see from Scheme

Carbenoid-mediated nucleophilic “hydrolysis” of 2-(dichloromethylidene)-1,1,3,3-tetramethylindane with DMSO participation, affording access to one-sidedly overcrowded ketone and bromoalkene descendants^§

• Rudolf Knorr,
• Thomas Menke,
• Johannes Freudenreich and
• Claudio Pires

Beilstein J. Org. Chem. 2014, 10, 307–315, doi:10.3762/bjoc.10.28

• -β) were detected in 33 while its C-2 atom was found to be aliphatic rather than olefinic. Although 33 is chiral, its only CH2 signal exhibits merely weak line-broadening instead of the expected AB splitting pattern; this indicated the center of chirality (sulfur) to be rather distant from CH2. The

Total synthesis of (+)-grandiamide D, dasyclamide and gigantamide A from a Baylis–Hillman adduct: A unified biomimetic approach

• Andivelu Ilangovan and
• Shanmugasundar Saravanakumar

Beilstein J. Org. Chem. 2014, 10, 127–133, doi:10.3762/bjoc.10.9

• (+)-grandiamide D (5). We assumed that the asymmetric Baylis–Hillman reaction [15] would be an ideal way to introduce chirality. Reaction between acryloyl sultam 19, and 2-((4-methoxybenzyl)oxy)acetaldehyde (14) in DMF [12], afforded cyclic product 20, which was then treated as such with TEA in ethanol to afford

Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

• Jun Hu,
• Jindan Wu,
• Qian Wang and
• Yong Ju

Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324

• . As shown in Figure 5, the fiber aggregates can be observed clearly with the red colour which can be attributed to the charge transfer band [53][54]. Chirality study It is known that many chiral gelators can form helical or twisted aggregates upon gelation [55][56]. Even achiral gelators have been

• reported to aggregate in both forms, right-handed and left-handed helices in equal proportions [57][58]. Therefore, circular dichroism (CD) was used to investigate the chirality of these CT gels and sol. The results showed a strong negative signal around 430 nm and a positive signal around 550 nm

Stereoselectively fluorinated N-heterocycles: a brief survey

• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2013, 9, 2696–2708, doi:10.3762/bjoc.9.306

• derivatives bearing a pendant nitrogen nucleophile, and the source of chirality was a substoichiometric quantity of the cinchona alkaloid derivative (DHQ)2PHAL (70). This method was shown to work very well with several different pendant nucleophiles, but the N-acetamido nucleophile was found to be optimal