Room-temperature Pd/Ag direct arylation enabled by a radical pathway

• Amy L. Mayhugh and
• Christine K. Luscombe

Beilstein J. Org. Chem. 2020, 16, 384–390, doi:10.3762/bjoc.16.36

• and the N-CH2-R on the alkyl chain indicate the product is highly branched [15]. Comparing the monomer’s spectrum to the polymer’s shows large peaks from unfunctionalized pyrrole rings at the chain ends with a ratio of interior to end groups of 1:0.57. While low molecular weight also contributes to

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• groups, was obtained with a slightly low molecular weight, suggesting improved solubility compared to 6a (R2 = Me and R1 = n-hexyl), the attempted dissolution of the obtained polythiophene 6b in chloroform was unsuccessful. Switching the oligosiloxane moiety to a branched derivative (R2 = (CH2)4Si(Me

Influence of the cis/trans configuration on the supramolecular aggregation of aryltriazoles

• Sara Tejera,
• Giada Caniglia,
• Rosa L. Dorta,
• Andrea Favero,
• Javier González-Platas and
• Jesús T. Vázquez

Beilstein J. Org. Chem. 2019, 15, 2881–2888, doi:10.3762/bjoc.15.282

• low-molecular-weight gelators have potential applications in high-tech materials [1][2][3] and biomedical sciences [3][4][5][6]. Triazole derivatives have shown excellent gelation properties [7][8][9][10], in addition to a broad range of biological activities [11][12][13][14]. During the synthesis and

• translucent/transparent low-molecular-weight gelator in aqueous solutions of DMSO, forming gels in DMSO/H2O, 2:1, v/v at a minimum concentration of 0.8% w/w. The presence of water favored gel formation, decreased the gelation concentration, and the gel's appearance became translucent/transparent. In addition

Self-assembly behaviors of perylene- and naphthalene-crown macrocycle conjugates in aqueous medium

• Xin Shen,
• Bo Li,
• Tiezheng Pan,
• Jianfeng Wu,
• Yangxin Wang,
• Jie Shang,
• Yan Ge,
• Lin Jin and
• Zhenhui Qi

Beilstein J. Org. Chem. 2019, 15, 1203–1209, doi:10.3762/bjoc.15.117

• water [56]. Following this water-centered view, we further explored a new type of supramolecular polymeric adhesive based on B21C7 derived low–molecular weight (LMW) monomer, in which the water molecules serve as essential co-monomers to the polymerization process, rather than as solvent [57]. Compared

Fabrication, characterization and adsorption properties of cucurbit[7]uril-functionalized polycaprolactone electrospun nanofibrous membranes

• Changzhong Chen,
• Fengbo Liu,
• Xiongzhi Zhang,
• Zhiyong Zhao and
• Simin Liu

Beilstein J. Org. Chem. 2019, 15, 992–999, doi:10.3762/bjoc.15.97

• or some low-molecular weight organic compounds [1][2][3][4][5]. With the unique advantages of ultrafine diameter, high specific surface area, controllable morphology, and easy functionalization, electrospun nanofibers have potential applications in various areas including drug delivery and tissue

Synthesis of polydicyclopentadiene using the Cp₂TiCl₂/Et₂AlCl catalytic system and thin-layer oxidation of the polymer in air

• Zhargolma B. Bazarova,
• Ludmila S. Soroka,
• Alex A. Lyapkov,
• Мekhman S. Yusubov and
• Francis Verpoort

Beilstein J. Org. Chem. 2019, 15, 733–745, doi:10.3762/bjoc.15.69

• cationic polymerization, are characterized by certain disadvantages. They have a low molecular weight, a fairly rigid structure of the polymer chains due to crosslinking processes occurring during polymerization. In addition, DCPD polymers obtained from "hard" catalytic systems, such as TiCl4, SnCl4, etc

LCST phase behavior of benzo-21-crown-7 with different alkyl chains

• Yan Deng,
• Xing Li,
• Qiao Zhang,
• Zheng Luo,
• Chengyou Han and
• Shengyi Dong

Beilstein J. Org. Chem. 2019, 15, 437–444, doi:10.3762/bjoc.15.38

• behavior and LCST properties are always limited to polymeric systems [20][21][22][23], nowadays more and more efforts have been made to rationally design LCST systems involving low-molecular-weight monomers [24][25][26]. However, compared with polymeric LCST systems, only a limited number of smaller

Fabrication of supramolecular cyclodextrin–fullerene nonwovens by electrospinning

• Hiroaki Yoshida,
• Ken Kikuta and
• Toshiyuki Kida

Beilstein J. Org. Chem. 2019, 15, 89–95, doi:10.3762/bjoc.15.10

• can be assembled into fibers/nonwovens by electrospinning. This result supports the notion that even small molecules (low-molecular weight compounds) with relatively weak inter/intramolecular interactions can be spun similar to the case of polymers. Since then, several small molecules, including

Copper(I)-catalyzed tandem reaction: synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and alkynes

• Muhammad Israr,
• Changqing Ye,
• Munira Taj Muhammad,
• Yajun Li and
• Hongli Bao

Beilstein J. Org. Chem. 2018, 14, 2916–2922, doi:10.3762/bjoc.14.270

• ], derived from the Huisgen’s 1,3-dipolar cycloaddition of azides and alkynes [22], has conceivably emerged as the premier example of click chemistry. Generally, organic azides are used as the azido source in most of the CuAAC reactions (Scheme 1a) [23]. However, the organic azides with low molecular weight

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• DAICEL CHIRALCEL® IA-3 column [tR = 12.65 min for the (S)-isomer and 14.50 min for the (R)-isomer (flow rate: 1.0 mL; eluent: hexane/iPrOH 95:5)]. Structures of cobalt–salen complexes 1–4. MALDI–TOF mass spectrum of the PO/PA copolymer. The low molecular weight copolymer for MS analysis was prepared by

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

• Christian Schütz and
• Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

• thermodynamic profiles as measured via isothermal titration calorimetry (ITC) [55]. Despite its low molecular weight, 13 showed tight-binding kinetics and was able to reduce production of HHQ, as well as PQS. Furthermore, it was capable of attenuating biofilm production [54]. All the information gathered via

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• ]. Both approaches were then combined into low molecular weight C-glycosidic sulfonamides, which resulted in very potent LecB and P. aeruginosa biofilm inhibitors with over 80% inhibition at a concentration of 100 µM [50]. Compound 18 of this series further showed very good in vitro stability against

Synthesis and supramolecular self-assembly of glutamic acid-based squaramides

• Juan V. Alegre-Requena,
• Marleen Häring,
• Isaac G. Sonsona,
• Alex Abramov,
• Eugenia Marqués-López,
• Raquel P. Herrera and
• David Díaz Díaz

Beilstein J. Org. Chem. 2018, 14, 2065–2073, doi:10.3762/bjoc.14.180

• gels are typically made of low-molecular-weight (LMW) compounds self-assembled in different solvents via non-covalent interactions. In most cases, this feature enables reversible stimuli-responsive gel-to-sol transitions [31]. Usually, the entanglement of 1D nanofibers of gelator molecules generates a

A self-assembled photoresponsive gel consisting of chiral nanofibers

• Lei Zou,
• Dan Han,
• Zhiyi Yuan,
• Dongdong Chang and
• Xiang Ma

Beilstein J. Org. Chem. 2018, 14, 1994–2001, doi:10.3762/bjoc.14.174

• ], and chemosensing [13][14]. Among the supramolecular gels, the low-molecular-weight gels (LMWGs) [15][16] are those that self-assemble into gels in organic solvents with molecular weights of <2000 Da. The weak noncovalent intermolecular interactions between LMWGs make them more sensitive to external

• of compound 3 in benzene that was investigated previously. Conclusion We have synthesized a novel chiral compound containing azobenzene as the photoresponsive group and UPy as the connection site. The monomer was capable of forming chiral nanostructures and a low-molecular-weight organogel in

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

• (CuAAC) reaction [28]. An alternative way is the functionalization of calix[4]arenes by terminal alkynyl groups. However, in this case further transformations by CuAAC reactions are limited mainly due to the fact that low molecular weight organic azides, especially containing less than 3 carbon atoms are

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• solubility of substrates in the ionic liquids (<10 mM) which rendered the phosphitylating agents prone to hydrolysis. Highly reactive phosphoramidite derivatives of low molecular weight amines could be isolated by this route (on 40–60 mg scales). Under the same conditions, coupling of bis(2-cyanoethyl

Carbohydrate inhibitors of cholera toxin

• Vajinder Kumar and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2018, 14, 484–498, doi:10.3762/bjoc.14.34

• exhibit binding affinity one order higher than m-nitrophenyl galactopyranoside (4) [48]. In another recent report, low molecular weight poly(N-acryloylmorpholine) was used to link galactose residues to form a bivalent inhibitor, but the biological assay demonstrated only moderate inhibitory activity [49

Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

• Raju Cheerlavancha,
• Ahmed Ahmed,
• Yun Cheuk Leung,
• Aggie Lawer,
• Qing-Quan Liu,
• Marina Cagnes,
• Hee-Chan Jang,
• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2017, 13, 2316–2325, doi:10.3762/bjoc.13.228

• final compounds, which were of low molecular weight and very polar. Nevertheless, the first synthesis of a δ-amino acid containing three vicinal fluorines on the backbone had been successfully completed. The all-syn target 6b was then obtained in a similar fashion from 40b (Scheme 4). The 1H and 19F NMR

A recursive microfluidic platform to explore the emergence of chemical evolution

• David Doran,
• Marc Rodriguez-Garcia,
• Rebecca Turk-MacLeod,
• Geoffrey J. T. Cooper and
• Leroy Cronin

Beilstein J. Org. Chem. 2017, 13, 1702–1709, doi:10.3762/bjoc.13.164

• containing higher molecular weight species exhibit greater osmotic pressure, and thus physically grow in size at the expense of their neighbours via osmotic effects [18][19][20]. This is particularly the case when microdroplets contain reactions that convert relatively simple, low molecular weight starting

Framing major prebiotic transitions as stages of protocell development: three challenges for origins-of-life research

• Ben Shirt-Ediss,
• Sara Murillo-Sánchez and
• Kepa Ruiz-Mirazo

Beilstein J. Org. Chem. 2017, 13, 1388–1395, doi:10.3762/bjoc.13.135

• involve low-molecular-weight species be launched in the lab, so that they manage to divide with regularity, explore an ample range of – sufficiently robust – phenotypes, and have potential to set up mechanisms for increasingly reliable heredity? It is easy to draw cones, arrows, dead ends, bifurcations

Synthesis of oligonucleotides on a soluble support

• Harri Lönnberg

Beilstein J. Org. Chem. 2017, 13, 1368–1387, doi:10.3762/bjoc.13.134

• other words, the support-bound material was separated from the low molecular weight substances by precipitation from Et2O and recrystallization from a mixture of MeCN and Et2O. In this case, four precipitation/recrystallization steps were needed in each coupling cycle: after detritylation, coupling

• average coupling yield was 96%. The mixture was concentrated and subjected to gel permeation chromatography in MeOH to remove the low molecular weight compounds. The pooled fractions containing the support-bound oligonucleotides were concentrated and oxidized with tert-butyl hydroperoxide. The excess of

• the support-bound oligonucleotide from low-molecular weight compounds by precipitation, have been utilized for the synthesis of oligoribonucleotides by phosphoramidite chemistry. A highly hydrophobic support that is well soluble in THF, CHCl3 and DCM, but insoluble in MeOH, MeCN and EtCN, has been

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• 1930, the first crystal structures of organic compounds to be investigated were carbohydrates of low molecular weight. Over the following years, only eight additional crystal structures were reported. The determination of the three dimensional structure of the dehydrated form of sucrose, in 1947, was

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• phenyl moieties and β-CD rings leading to daisy chains [54]. The polymerization of 7 was performed through Glaser coupling in pyridine catalyzed by Cu(I)/Cu(II). After removal of low molecular weight material by ultrafiltration polymer 8 was isolated as a light orange solid in 91% yield. Polyrotaxane

Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

• Cristian Peptu,
• Mihaela Balan-Porcarasu,
• Alena Šišková,
• Ľudovít Škultéty and
• Jaroslav Mosnáček

Beilstein J. Org. Chem. 2017, 13, 779–792, doi:10.3762/bjoc.13.77

• modification with small molecular weight compounds are taking advantage of the different reactivity of the hydroxy groups in 2, 3 or 6 position, thus allowing selective modifications [3]. While modified CDs with low molecular weight substituents, such as methyl, (2-hydroxy)propyl, sulfobutyl, etc. are already

• oligomer mixtures [24][25]. However, the presence of PLA oligomers was clearly confirmed by LC–ESI–MS, which has a better sensitivity for linear low-molecular-weight oligolactides. In the case of MALDI–MS identification, the presence of the substance used as matrix prevents accurate observation of the

• oligomers can be justified by water initiation of L-lactide ring opening. The relative amount of homooligolactide species is highly exaggerated in the presented ESI chromatogram (Supporting Information File 1, Figure S22) due to mass discrimination of low-molecular-weight compounds (PLA) against co-eluting

Versatile synthesis of the signaling peptide glorin

• Robert Barnett,
• Daniel Raszkowski,
• Thomas Winckler and
• Pierre Stallforth

Beilstein J. Org. Chem. 2017, 13, 247–250, doi:10.3762/bjoc.13.27

• initiated by pulses of chemoattractive, low-molecular weight signaling molecules – so-called acrasins [5]. Additionally, it has been shown that natural products are also involved in interspecies interactions of social amoebae and bacteria [6][7][8][9][10]. A detailed investigation of both inter- and