First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

• Maxime Pypec,
• Laurent Jouffret,
• Claude Taillefumier and
• Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

• , is consistent with intramolecular hydrogen bond interaction, which is accompanied by a reduction of the exchange rate of the NH proton. In DMSO, we observe reduced NH linewidths, consistent with the fact that this solvent has strong hydrogen bonding and solvation abilities which reduce significantly

• proton exchange. Overall, the NMR study suggests that the N-methylamino glycine monomer and oligomers have a strong propensity to form intermolecular hydrogen bonds, an interesting and sought-after property for self-assembling and interaction with biological targets. Neat peptoids 1–6 were also

• ); (C) overview of the hydrogen bonding network (conformation A depicted in blue, conformation B in orange), hydrogen bonds (light blue dashed lines), hanging hydrogen bonds (light green dashed lines). NOE effect interaction observed in the 2D-NOESY spectra of monomer 1 and dimer 2 in DMSO-d6

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

• Virginija Jakubkiene,
• Gabrielius Ernis Valiulis,
• Markus Schweipert,
• Asta Zubriene,
• Daumantas Matulis,
• Franz-Josef Meyer-Almes and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

• were synthesized by the interaction of esters 3, 4, and 6–9, with hydroxylamine in water at 0–5 °C (in case of ester 7, in a mixture of water and methanol 1:1 at room temperature). To investigate the effect of an alkyl substituent at the fifth position of the pyrimidine ring and the length of the

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• of nitrogen-containing heterocycles in the fluorescent materials, the addition of a Lewis acid tended to induce red-shifted absorption and emission, shedding light on the fact that the Lewis acid interacts easily with the nitrogen-containing fluorescent materials. This interaction mechanism is the

• brand new luminescent properties. In this mini-review, we summarize unique electron donor and acceptor materials which regulate luminescent properties via Lewis acid–base interactions and briefly explain the exploration of their chemical nature and interaction mechanisms. Review Lewis acids as electron

• –base interaction mechanisms Chemical essence of Lewis acid–base interaction All the above discussed fluorescent materials share the common characteristics of Lewis basicity. Therefore, the changes in band gaps and colors of the donor materials is essentially attributed to a Lewis acid–base complexation

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• the interaction of the lowest unoccupied molecular orbital (LUMO) of the azomethine ylide 1 with the highest occupied molecular orbital (HOMO) of cyclopropenes 2. It follows that the greater the nucleophilicity of the cyclopropene substrate 2 is, the higher is its reactivity towards the 1,3-dipole 1

Structural basis for endoperoxide-forming oxygenases

• Takahiro Mori and
• Ikuro Abe

Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71

• the fatty acyl chain is bound deeply into the narrow hydrophobic channel (Figure 2B and 2C) [48][52][53]. Structural and biochemical studies of ovine COX-1 indicated that the ionic interaction between the carboxylate of AA and Arg120 is required for the reaction (Figure 2B) [54][55][56]. In contrast

• , this interaction is not essential in COX-2, suggesting that the hydrophobic interactions between the acyl chain and the active site residues in the cyclooxygenase channel are important for AA binding to COX-2 (Figure 2C) [57][58]. This is one of the major structural differences between COX-1 and COX-2

Rapid gas–liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide

• Kyoko Mandai,
• Tetsuya Yamamoto,
• Hiroki Mandai and
• Aiichiro Nagaki

Beilstein J. Org. Chem. 2022, 18, 660–668, doi:10.3762/bjoc.18.67

• for safe, low-cost, and environmentally benign operations. Initially, we decided to maintain the key flow conditions such as the flow rate since it severely affects the fluidic interaction inside a flow reactor and thus the reaction efficiency of this type of gas–liquid reaction. Thus, the flow rate

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• the electrostatic interaction of crown ethers and alkali metals [4]. While, in the beginning, crown ethers were an excellent choice for metal ion complexation, they later received ample recognition as supramolecular catalysts [49]. The majority of host capsules, however, has been constructed using

• aromatic walls that offer van-der-Waals and π–π stacking interactions in order to compensate for the absence of a strong electrostatic interaction. These non-covalent/ionic interactions play an important role in encapsulating aromatic organic molecules, especially in aqueous medium. Along this rationale

• building blocks to decorate the inner cavity of the host would produce efficient types of catalyst, where the substrates get activated for a particular reaction upon interaction with the functional group inside the cavity. Mukherjee et al. have demonstrated the construction of 3D nanocages employing

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• approach [23]. Initial UV irradiation of pyrazole 12a and subsequent interaction with NaBH3CN results in the formation of the product 18 in 67% yield (Scheme 7). It should be noted that the reaction proceeds regiospecifically with the participation of one carbonyl group. Also worth mentioning is the

Syntheses of novel pyridine-based low-molecular-weight luminogens possessing aggregation-induced emission enhancement (AIEE) properties

• Masayori Hagimori,
• Tatsusada Yoshida,
• Yasuhisa Nishimura,
• Yukiko Ogawa and
• Keitaro Tanaka

Beilstein J. Org. Chem. 2022, 18, 580–587, doi:10.3762/bjoc.18.60

• /ΦEtOH) was smaller than 1.0. These results indicated that aggregation was induced by π–π stacking interaction of the planar structures of compounds 3a and 3b in aqueous solution and that their excited states decayed by non-radiative pathways, resulting in ACQ. In contrast, the fluorescence intensities

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• host. These results suggested that MV could be effectively released from the cavity of TBTQ-CB6 by the competitive host–guest interaction of SM, since the binding affinity between TBTQ-CB6 and SM was about seven times higher than that between TBTQ-CB6 and MV. Competitive replacement of DOX from the

Unusual highly diastereoselective Rh(II)-catalyzed dimerization of 3-diazo-2-arylidenesuccinimides provides access to a new dibenzazulene scaffold

• Anastasia Vepreva,
• Alexander S. Bunev,
• Andrey Yu. Kudinov,
• Grigory Kantin,
• Mikhail Krasavin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55

• formation of a single diastereomer at the cyclopropanation step can be explained by the preferred approach of carbene A from the least sterically hindered side of indene C and the π-stacking interaction of the aromatic fragment of indene and the benzylidene substituent of the carbene. The conversion of

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• desymmetrization of meso-1,2-diols [58]. The [2]rotaxane (R)-42 was synthesized by interaction of the ammonium salt 41 with the BINOL-based macrocycle (R)-12 and end-capping with 3,5-di-tert-butylbenzoic acid (see Figure 10). In the asymmetric desymmetrization reaction of meso-hydrobenzoin, rotaxane (R)-42 gave

• theory (DFT) studies suggested that the excellent stereoselectivities of the catenane are a direct result of the cooperative interaction of both phosphoric acid groups, enabled by the mechanical bond. Follow-up studies showed that such acid–acid interactions are also relevant for monophosphoric acid

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• package Gaussian 09 [52]. The solvation behaviour of the surrounding toluene was estimated by the polarizable continuum model. Although the B3LYP/6-31G(d) theory level due to the neglected long-range exchange interaction can give less accurate results for calculated molecular geometries and transition

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

• , a plausible catalytic mechanism is represented in Figure 2. The MAHT substrate is deprotonated by one of the tertiary amine sites, and the formed enolate intermediate can be stabilized by hydrogen bonding-mediated ion-pair interaction within the macrocyclic cavity. The imine substrate is activated

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• photosynthesis and exhibited a high catalytic efficiency for the photocatalytic dehalogenation reaction of various bromoketone derivatives with good yields in short reaction time in water. Keywords: aggregation-induced emission; Förster resonance energy transfer; host–guest interaction; photocatalysis

• interaction between m-TPEWP5 and G (1 equiv of each) in D2O. A strong cross-correlation peak was perceived between the m-TPEWP5 aromatic protons and the Hc proton of G. The above results evidenced that the alanine pendant of the guest unit stayed in the m-TPEWP5 cavity. Besides, in order to confirm the host

• binding interaction between m-TPEWP5 and G is strong enough to form a stable complex in an aqueous solution. The morphology of the supramolecular m-TPEWP5G and m-TPEWP5G-EsY systems was monitored by using transmission electron microscopy (TEM). As shown in Figure 3, m-TPEWP5G self-assembled to form a worm

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• [17]. Also, M2CO3-catalyzed (M = K or Cs) addition of phenols to bromoacetylenes produced bromovinyl phenyl ethers, which were converted into 4H-chromen-4-ones, benzo[b]furans, etc. [18][19][20][21]. The latter reaction attracted our attention and prompted us to explore the interaction of phenols and

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• interactions between catalysts Ch1, Ch2 and acetone were examined by 13C NMR experiments in CD2Cl2. The interaction between bidentate catalyst Ch1 or monodentate catalyst Ch2 and acetone could result in a variation of the 13C signal of the carbonyl group. Analysis of a 1:1 mixture of Ch1 and acetone in CD2Cl2

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• reaction, the anthracene moiety stacks onto the planar triazine of B through π–π stacking and possible charge-transfer interaction between each other, which stabilizes the complex. However, after the reaction, the framework of the product is bent at the 9,10-position, which undermines the host–guest

• stacking interaction. The complex of B and the product is hence destabilized, resulting in the replacement by incoming reactants. This beautiful pioneering work showed elegant examples of how the designed and synthetic molecular containers could mediate and even control the site-selectivity of organic

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• . Various reactant pairs were treated with 2.5 mol % of one out of 3 palladium-containing perovskites, with Et3N in a solvent mixture of 5% H2O in DMF/DMA at 120 °C. Furthermore, the presence of hydrophobicity on the surface of the LaCoO3 catalyst can improve the interaction between the precursors of the

Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

• Angel Ho,
• Austin Pounder,
• Krish Valluru,
• Leanne D. Chen and
• William Tam

Beilstein J. Org. Chem. 2022, 18, 251–261, doi:10.3762/bjoc.18.30

• to form IN2b, via 1bTS2b. Understandably, the steric interaction between the C1-substituent and the acyl group is responsible for this energy difference. The relative energy of the hydrometalated intermediates (IN2a and IN2b) are comparable to their preceding intermediates with IN2a being 0.5 kcal

Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• -Lysine binding [39]. Although PLP is not a reported neuraminidase inhibitor, its main interaction in the active site could be reasoned based on previous results with sialic acid-derived phosphonate analogues. In this regard, it has been suggested that the inhibition of different strains of influenza

• virus neuraminidase is due to a strong electrostatic interaction between the phosphonate group and the arginine pocket in the active site [40]. Conclusion A small series of anomeric 1,2,3-triazole-linked sialic acid derivatives was synthesised in good yields and high purity via CuAAC click chemistry and

Asymmetric organocatalytic Michael addition of cyclopentane-1,2-dione to alkylidene oxindole

• Estelle Silm,
• Ivar Järving and
• Tõnis Kanger

Beilstein J. Org. Chem. 2022, 18, 167–173, doi:10.3762/bjoc.18.18

• ). When instead of a benzylidene-containing substrate an alkylidene with an extra ester moiety was used, the enantioselectivity was lost and the product 3i was obtained as a racemic mixture. Either additional coordination with the catalyst or a lack of π–π-interaction may have been responsible for that

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

•  1a). The spectroscopic FTIR study revealed the interaction between the metal and the NH2 and OH groups of chitosan. In both spectra, the peaks around 1100, 1400, 1600, and 2900 cm−1 corresponded to the C–O, C–N, and N–H (bending) as well as to the C–H bonds of the chitosan moiety, respectively. The

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• on reactions believed to involve a direct interaction with the substrate, or with a species (such as a cation) directly formed from the substrate. Sulfonyl chlorides were included in several early considerations of the reaction rates, for processes involving organic substrates, as a function of

• TFE replaced by the even more electrophilic 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) component. The 97% TFE has a YCl value (for interaction at chlorine) of 2.83, which increases to 5.08 on going to 97% HFIP [25], corresponding to a considerable increase in its ability to interact with, and assist in

• the specific rates of solvolytic displacement of chloride ions by nucleophilic interaction at the sulfur of sulfonyl chlorides (RSO2Cl) whose structures are tabulated and related to compound numbers in Table 1. The specific rate ratios for solvolyses in 40% ethanol/60% H2O (v/v) relative to those in