Copper-catalyzed multicomponent reactions for the efficient synthesis of diverse spirotetrahydrocarbazoles

• Shao-Cong Zhan,
• Ren-Jie Fang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 796–808, doi:10.3762/bjoc.18.80

• ][11][12][13][14][15]. Among many well-designed strategies for the synthesis of tetrahydrocarbazoles, the direct assembly of the tetrahydrocyclohexenyl ring with readily available functionalized indoles as precursors has proven to be one of the most efficient synthetic protocols [16][17][18][19][20][21

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

• heteromeric complexes by Issacs’ classification [32] of two main categories: (a) social self-sorting, which involves the assembly of different species, and (b) narcissistic self-sorting, which only involves aggregation of the same component. Over the past few years, a variety of social self-sorting protocols

• Switchable catalysis due to reversible assembly/disassembly Toggling between intra- and intermolecular complexation in nanoswitches Review Catalysis using heteroleptic discrete supramolecular architectures In its early years, supramolecular chemistry mainly focused on host–guest interactions, primarily on

• and size of their cavity requires often tedious de-novo synthesis. Eventually, these drawbacks have been tackled by synthesizing discrete supramolecular hosts based on metal–ligand coordination-driven self-assembly [15][16][17][18][19][20][21][22][52]. This approach not only solved the issue with low

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

• ) derivatives are a class of molecules possessing a rigid bowl-shaped structure and a C3v-symmetric skeleton [21]. Bearing similarity with macrocycles in general, they can act as versatile hosts for encapsulating guest molecules. Over the past two decades, host–guest interactions and self-assembly based on TBTQ

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

• containing electron-rich hydroquinone or 1,5-dioxynaphthalene units (macrocycles 15/21/23), together with suitable dicationic bis-bipyridinium precursors (16/19). Self-assembly of the corresponding pseudorotaxanes by π–π stacking, following by capping with dibromo-p-xylene 17 gave rise to a series of chiral

• mechanical bond, namely from a BINOL-based macrocycle onto the axle. First, they developed [2]rotaxane 27 [52]. Here, the methacrylate-functionalized ammonium salt 25 and the bis-BINOL macrocycle (R,R)-26 give the pseudorotaxane (R,R)-27 through self-assembly. Stoppering of the pseudorotaxane was achieved by

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

• Mannich reactions; supramolecular catalysis; thiourea; Introduction In the past decades, the development of supramolecular chemistry has enabled abundant host scaffolds and assembly tools for boosting catalytic processes, and stimulated the emergence of supramolecular catalysis [1][2][3][4][5][6][7][8][9

• tetraamino-bisthiourea chiral macrocycles were synthesized [30]. When applied in catalyzing the decarboxylative addition of phenyl β-ketoacids to cyclic imines bearing sulfamate heading group, an interesting substrate-induced assembly catalysis mode was uncovered [30]. To expand more applications, herein we

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

• supramolecular self-assembled nanosystem based on host–guest interactions between water-soluble tetraphenylethylene-embedded pillar[5]arene (m-TPEWP5) and ammonium benzoyl-ʟ-alaninate (G) in an aqueous medium. The obtained assembly of m-TPEWP5 and G showed aggregation-induced emission (AIE) via the blocking of

• intramolecular phenyl-ring rotations and functioned as an ideal donor. After the loading of eosin Y (EsY) as acceptor on the surface of the assembly of m-TPEWP5 and G, the worm-like nanostructures changed into nanorods, which facilitates a Förster resonance energy transfer (FRET) from the m-TPEWP5 and G

• assembled donor to the EsY acceptor present in the nanorod assembly. The system comprising m-TPEWP5, G and EsY displayed moderate FRET efficiency (31%) at a 2:1 molar ratio of donor-to-acceptor. Moreover, the obtained supramolecular nanorod assembly could act as a nanoreactor mimicking natural

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• presence of electron-rich aromatic surfaces. In a recent publication, Reek [22] further investigated the self-assembly properties of 1 as function of the content of water in chloroform-d demonstrating that the symmetrical hexameric capsule 16·(H2O)8 comprising 8 water molecules (capsule A) is present only

• evidence of the importance of an accessible cavity for the activation of the reaction after alcohol protonation. It is known that 16 behaves as a weakly acidic assembly with pKa of about 5.5 [42], while the resorcinol moiety presents a pKa of 9.15. This enhanced acidity is likely to promote the protonation

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

• phosphonium selenide catalysts which showed catalytic activity in assembly reactions [41], Michael addition reactions [41], Rauhut–Currier reactions [42], cyanosilylation reactions [43], and cycloaddition of vinylindoles through chalcogen–π bonding catalysis [44]. Our previous works demonstrated that Se···O

New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence

• Long Zhao,
• Mao-Lin Yang,
• Min Liu and
• Ming-Wu Ding

Beilstein J. Org. Chem. 2022, 18, 286–292, doi:10.3762/bjoc.18.32

• of their derivatives [12][13][14][15][16][17][18][19][20][21][22]. For example (Scheme 1), a one-pot Tf2O-mediated assembly of amides, amines, and ketones provided 3,4-dihydroquinazolines in good yields via successive triflic anhydride-mediated amide dehydration, ketimine addition, and Pictet

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

• ) moiety since it can easily undergo aggregation-induced emission enhancement (AIEE). The self-assembly of the HPB derivative resulted in the formation of fluorescent aggregates, which can act as a stabilizer or as a reactor for the development of α-Fe2O3 nanoparticles at room temperature. The catalytic

Synthesis and bioactivity of pyrrole-conjugated phosphopeptides

• Qiuxin Zhang,
• Weiyi Tan and
• Bing Xu

Beilstein J. Org. Chem. 2022, 18, 159–166, doi:10.3762/bjoc.18.17

• of 1. These results suggest that a heteroaromatic motif at the N-terminal of peptides likely disfavors the formation of extensive nanofibers or morphological changes during enzymatic self-assembly, thus provide useful insights for the development of phosphopeptides as substrates of phosphatases for

• controlling cell fate. Keywords: cells; enzyme; N-terminal; peptides; pyrroles; self-assembly; Introduction Biomacromolecular assemblies have received considerable attention recently in the field of biomaterials [1][2][3][4][5][6][7], among which peptides are of particular interest because of their unique

• ][11], collagen mimic [12], antibacterial [13][14], biomineralization [15][16], mimicry of amyloids [17], cell cultures [18], and tissue engineering [19]. Particularly, the use of enzyme-instructed self-assembly (EISA) [20][21] of peptide assemblies has expanded the applications of peptide assemblies

Earth-abundant 3d transition metals on the rise in catalysis

• Nikolaos Kaplaneris and
• Lutz Ackermann

Beilstein J. Org. Chem. 2022, 18, 86–88, doi:10.3762/bjoc.18.8

• , Germany 10.3762/bjoc.18.8 Keywords: C–H activation; 3d transition metals; green chemistry; late-stage functionalization; sustainability; Transition metal catalysis has emerged as a transformative platform for the assembly of increasingly complex compounds, with enabling applications to natural product

• industries as one of the most powerful methods for molecular assembly. With regard to the cost of goods and the allowance of trace metal impurities in medicinally relevant compounds, 3d transition metal complexes, such as those of iron, copper, cobalt or nickel, represent exciting, more sustainable

• functionalization enabled the de novo assembly of bioactive molecules [9]. The full potential of the mild nature of C–H functionalization is unlocked by the merger with modern photochemistry and electrocatalysis manifolds. In this context, recent advances were realized by the combination of photoredox catalysis and

Polymer chemistry: fundamentals and applications

• Bernhard V. K. J. Schmidt

Beilstein J. Org. Chem. 2021, 17, 2922–2923, doi:10.3762/bjoc.17.200

• supramolecular chemistry for the assembly of polymer fibers and the synthesis of well-defined polysaccharides. In the direction of materials, cryogels and reinforced hydrogels are discussed, as well as 3D-printed poly(caprolactone) biomaterials. In addition, properties of thermoresponsive materials and self

• -healing materials are presented in this thematic issue. Finally, the use of polymerization-induced self-assembly for the synthesis of drug carriers is presented. The issue also shows the multidisciplinary character of polymer science, for example when supramolecular motifs, organic coupling reactions or

Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies

• Tanmoy Halder and
• Somnath Yadav

Beilstein J. Org. Chem. 2021, 17, 2915–2921, doi:10.3762/bjoc.17.199

• involving the [1 + (1 + 1 = 2)] assembly, followed by a one-pot synthesis involving [1 + 1 + 1] strategy from the corresponding monosaccharides. The one-pot method provided a higher yield of the protected trisaccharide intermediate (73%) compared to the two step synthesis (66%). The protected trisaccharide

• co-worker accomplished the total synthesis of a O-polysaccharide of Providencia alcalifaciens O22 via a one pot assembly of the oligosaccharide unit [36]. Recently in 2020 Werz and co-workers completed the total synthesis of a tri-, hexa-, and heptasaccharide of the O-polysaccharide of Providencia

• the hitherto not synthesized above trisaccharide repeating unit containing two ᴅ-galactose and one N-acetyl-ᴅ-galactosamine moieties. The linear synthesis of the target oligosaccharide was first carried out via a linear [1 + (1 + 1 = 2)] assembly of a galactopyranose donor with a GalpNTroc–Galp

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• reported a similar approach towards the assembly of 2,2-disubstituted indolines from N-sulfonylanilines and substituted styrene derivatives [93]. In 2014, the Jiao group investigated the carbosulfonation of alkenes 60 for the synthesis of oxindoles 90 through sequential C–S/C–C-bond formation (Scheme 16

• a four-component radical dual difunctionalization and ordered assembly of two chemically distinct alkenes 114/115, aldehyde 65, and tert-butyl peroxide (Scheme 23) [108]. In order to selectively couple one alkene to another, without the formation of oligomers, the authors utilized the different

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• provides an efficient entry into the rapid assembly of various diarylmethyl sulfones and isonitrile diarylmethanes (Scheme 1C). Results and Discussion We commenced the study by using p-QMs 1a and TosMIC (2a) as model substrates to optimize the reaction conditions. As shown in Table 1, when 1a and 2a were

• assembling various diaryl methyl sulfones and isonitrile diarylmethanes. In the follow-up study, it was found that the isonitrile diarylmethanes are versatile building blocks for the rapid assembly of a series of compounds with novel structures. We are studying this part of the work. Experimental General

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• bisamide derivatives that are both axially and centrally chiral (Scheme 28). Very recently, the same group reported the first CPA-catalyzed asymmetric assembly of axially chiral arylalkene-indole scaffolds by organocatalytic (Z/E)-selective and enantioselective (4 + 3)-cyclization using (3-alkynylindol-2

Adjusting the length of supramolecular polymer bottlebrushes by top-down approaches

• Tobias Klein,
• Franka V. Gruschwitz,
• Maren T. Kuchenbrod,
• Ivo Nischang,
• Stephanie Hoeppener and
• Johannes C. Brendel

Beilstein J. Org. Chem. 2021, 17, 2621–2628, doi:10.3762/bjoc.17.175

• methods represent an easily implementable technique toward 1D polymer nanostructures with an adjustable length in the range of interest for perspective biomedical applications. Keywords: distribution; dual centrifugation; filomicelles; self-assembly; ultrasonication; Introduction Cylindrical polymer

• desired applications in nanomedicine [4][5]. A key factor in this regard are formulation strategies, which allow a straightforward implementation into established processes that are, e.g., in accordance with good manufacturing practice (GMP) [6]. Approaches such as the crystallization-driven self-assembly

• the conditions for the assembly process, and are therefore often limited to specific materials. An alternative is the use of molecular motifs capable of forming directional supramolecular interaction forces, such as hydrogen bonds or π-interactions, to guide the one-dimensional (1D) assembly of

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• through deviation of the salimethyloxazolinyl-thioester intermediate 8 from the assembly line via an unusually facile C–N-bond opening of the ring to generate an ester bond, and followed directly by amination (+ NH3), the addition of histamine and phenethylamine units to form compounds 1, 2, and 3

Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands

• Janina-Miriam Noy,
• Fan Chen and
• Martina Stenzel

Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148

• more structural investigations are required to elucidate this. Keywords: micelle; mitochondria; phosphorylcholine; PISA; polymerization-induced self-assembly; Introduction Targeting mitochondria is a promising strategy for the development of new anticancer drugs [1]. Among them, organoarsenical drugs

• suitability as a potential vehicle to deliver these drugs. Disadvantage is however the multistep procedure to generate micelles ranging from the synthesis of block copolymers to the self-assembly into micelles, often in low dilution, making the process inefficient. Micelles obtained by the PISA process can in

• contrast generate large amounts of nanoparticles in a reproducible manner. PISA nanoparticles have been frequently investigated as drug carriers. The challenge is often how to entrap the drug during the self-assembly process. Addition of drugs during the PISA process is possible [33][34], but it needs to

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• this protocol using the chiral iPrBiOx ligand under slightly modified reaction conditions (Scheme 19) [72]. Recently, Chu achieved the selective assembly of vinyl and aryl functionalities onto saturated cyclic hydrocarbons via a photoredox nickel-catalyzed sequential C–O decarboxylative vinylation

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• physicochemical interplay between the architecture of the polymer assembly and the resulting thermoresponsive switching behavior will be in the foreground of this consideration. Keywords: lower critical solution temperature (LCST); responsive coating; smart material; thermoresponsive polymer; upper critical

• -assembly due to their structure consisting of hydrophilic and hydrophobic units [110][111][112][113]. In the case of rather large corona blocks compared to the core-forming blocks, such structures are usually star-shaped and spherically composed of many individual chains by noncovalent interchain

• absolute length of the block copolymer and the relative length of the blocks to each other and the glass transition temperature. If a block is composed of a thermoresponsive polymer, the amphiphilic character and self-assembly ability can be altered by changing the temperature. The thermoresponsive block

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• approach (also known as fragment coupling) allows connecting pre-assembled oligosaccharide blocks. To decrease the synthetic time required for the chemical synthesis of polysaccharides, automated techniques have been developed [28][29][30][31]. Automated glycan assembly (AGA) connects monosaccharide BBs on

• a solid support following a linear approach (Figure 1D). Cycles of glycosylation and selective deprotection are iteratively performed to access the desired polysaccharide with full control over the length and the monosaccharide sequence [32]. Upon completion of the assembly, the desired product is

• of the self-assembly of cellulose chains at the active site of the enzyme suggested that diffusion of the aggregated molecules and the monomers around the active center dictates the DP that can be obtained by enzymatic polymerization [70][71]. This could be the reason causing enzymatic reactions to

Asymmetric organocatalyzed synthesis of coumarin derivatives

• Natália M. Moreira,
• Lorena S. R. Martelli and
• Arlene G. Corrêa

Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128

• multicomponent reaction (IMCR) [31]. The enantioenriched hemiacetals 5 were obtained using the Jørgensen catalyst 7 as previously described by Rueping et al. [32]. This approach enables the rapid assembly of complex natural product hybrids 6 including up to four different molecular fragments, such as

Cationic oligonucleotide derivatives and conjugates: A favorable approach for enhanced DNA and RNA targeting oligonucleotides

• Mathias B. Danielsen and
• Jesper Wengel

Beilstein J. Org. Chem. 2021, 17, 1828–1848, doi:10.3762/bjoc.17.125

• amine functionalities in their neutral, i.e., non-protonated form. Regarding synthetic strategies, both the use of amine group functionalized phosphoramidites, i.e., functionalized monomeric building blocks, as well as conjugation with amine groups after completion of the ON assembly, are being