Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• catalytic arrangements of the most enantioselective catalysts, including anchoring on polystyrene beads [8][9], magnetic nanoparticles [10], or block copolymers composed of PEG-poly(Glu) [11]. These modifications have facilitated the recycling of the catalysts, offering numerous advantages, including

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• . Therefore, RAFT is often used to perform chain expansion reactions or to synthesize functionalized multi-block copolymers [62][63][64]. Boyer and co-workers developed a photocatalytically mediated RAFT polymerization, PET-RAFT, which removes the requirement for conventional radical initiators. The reaction

• -free ROMP are shown in Scheme 12C. Meanwhile, metal-free ROMP is applied to monomers like functionalized norbornenes and dicyclopentadienes (DCPD) (Scheme 12D) to synthesize polymers and block copolymers [88][92][93]. 3 Post-polymerization radical chemistry Post-polymerization modification is a

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• distribution (Figure S13 in Supporting Information File 1). Polymerization and copolymerization of 2-butyl-2-oxazoline As mentioned, POx are desirable polymers for biomedicine. Under the right conditions, the living nature of CROP makes it possible to produce polymers, copolymers, and block copolymers with

• clear bimodality, but the molar mass distribution was slightly lower (Ð = 1.45) compared to PBuOx obtained from EtOxMeOTf (Figure S14, Supporting Information File 1). POx-based block copolymers are well known to formulate poorly water soluble drugs and Haider et al. recently compared the drug loading

• formulation, which strongly depends on the molar mass distribution and composition of the polymer. In conclusion and somewhat expectedly, DLG is not suitable for the synthesis of high quality block copolymers under given conditions. Conclusion In conclusion, we report for the first time attempts to use the

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

• 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

• subject to CC BY 4.0. Summary of the pPEGMA and pMPC block copolymers prepared by PISA at 70 °C including the hydrodynamic diameter Dh and particle size distribution PdI obtained by DLS and the drug loading content (DLC) calculated using DLC = m(PENAO)/[m(PENAO) + m(polymer)]. The table here contains the

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

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

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

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• ) photopolymerization under visible-light irradiation in an aqueous solution [48]. Briefly, the supramolecular PDI–CB[7] complex in Figure 15 acts as a photocatalyst at a low concentration (1 ppm relative to the monomer), which could be utilized for the preparation of a series of homo- or block copolymers with an

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• (II)-catalyst scaling in ppm amount in combination with a NIR sensitizer facilitated tailor-made synthesis of block copolymers [81]. This helped to reduce the heavy metal concentration in the polymerization system at a low level and complements therefore several methods developed to operate at low

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

• Patrycja Żak and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

• copolymerization of norbornenylethyl-POSS with methyltetracyclododecene in the presence of first generation Grubbs catalyst (Ru-1) is a practical route to the synthesis of block copolymers containing POSS nanoparticles (Scheme 26) [50]. ROMP of norbornenylethyl-POSS produced the corresponding homopolymer in

• ca. 48000–63000 Da. The synthesized POSS containing nanocomposites displayed significant improvements in their thermal stability relative to that of the polynorbornenes formed in the absence of POSS cages. Xu has reported an example of the synthesis of POSS-containing block copolymers via “living

• polymer was isolated by precipitation. As a result two block copolymers were obtained. The one containing 5% of POSS units was characterized by Mn = 26200 Da and PDI = 1.16 and the other one bearing 10% of POSS-substituted monomeric units, has a number average molecular weight Mn = 33200 Da and a

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• polymerization in a living fashion turned it into a powerful tool of polymer design [1]. Hundreds of linear, comb-like, graft-, bottle-brush, ladder, and other homopolymers and copolymers were synthesized [2][3][4][5][6][7]. Block copolymers combining properties of two or more individual polymers in one material

• attract ongoing attention from both experimentalists and theoreticians due to their intrinsic tendency to self-assemble into diverse microstructures [8][9][10][11]. Technological applications of block copolymers cover lithography [12], photovoltaics [13], membranes [14] and many other areas [15]. Most of

• polymerization (ATRP) and сlick reactions for the precise synthesis of amphiphilic ABCBA-type block copolymers (Scheme 4) [63]. A more facile “one-pot” procedure for the synthesis of an end-functionalized conjugated multiblock copolymer with PFV main chain was accomplished by combining olefin metathesis and

Selective ring-opening metathesis polymerization (ROMP) of cyclobutenes. Unsymmetrical ladderphane containing polycyclobutene and polynorbornene strands

• Yuan-Zhen Ke,
• Shou-Ling Huang,
• Guoqiao Lai and
• Tien-Yau Luh

Beilstein J. Org. Chem. 2019, 15, 44–51, doi:10.3762/bjoc.15.4

• in polymer synthesis [24]. Since the first living ROMP methods for cyclobutenes were reported in 1992 [25], cyclobutene-containing block copolymers are well documented [26][27][28][29][30][31][32][33][34]. Alternating cyclobutene–cyclohexene copolymers have been synthesized by ROMP of the

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• block copolymers and G-0 monomeric or dimeric dendritic liquid crystals with photochromic azobenzene mesogens. The present ab initio study explores a previously unknown use of 4-(n-octyloxy)aniline in the synthesis, structure and supramolecular behaviour of new dendritic melamines. Results: Starting

• -dendritic block copolymers [24] and G-0 monomeric or dimeric dendritic liquid crystals with photochromic azobenzene mesogens [25] called attention on the use of 4-(n-octyloxy)aniline as key building block in the above macromolecules’ elaboration. These recent findings can be seen as well as advances

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• %. Contrary to the results obtained in bulk, using micelles resulted in higher yields even after catalyst recycling, providing a promising catalytic platform for these coupling reactions [70]. Lee et al. described an approach to perform catalysis in micelles based on rod–coil block copolymers [71]. Micelles

• membrane. Furthermore, the nanosystem also facilitated catalyst recycling by normal extraction. 2.2. Polymeric vesicles Polymeric vesicles or polymersomes are synthetic bilayered hollow architectures that are self-assembled from amphiphilic block copolymers [73]. The synthetic nature of polymersomes allows

• switching procedures can be prevented. Although this requires still much development, it is to be expected that in the near future nanoreactors will be key to a more sustainable production of fine chemicals. Assembly of catalyst-functionalized amphiphilic block copolymers into polymer micelles and vesicles

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• monomer by RAFT polymerization. This allows the control over the molecular weight of ionic liquid blocks in the range of 8000 and 22000 and of the block-copolymer synthesis. In this work we focus on block copolymers with an anchor block. They can be used to control the formation of TiO2 nanoparticles

• polymers with narrow polydispersity, controlled molecular weight and also well-defined block copolymers. Such block copolymers with ionic liquid blocks might enable to control the properties of PILs spatially. An interesting aspect of this might be (i) a reduction of the dimension of the ion conductivity

• in PIL block copolymers due to their demixed morphology or (ii) the control of ion conduction near surfaces, if PIL brushes are fixed to a surface [13]. This last example of a spatially restricted access of ions to a surface can be very interesting in combination with redox reactions [14][15], a case

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• ]. RAFT polymerization is a useful tool to form well-defined block-copolymers starting from a chain transfer agent (CTA) that drastically reduces the actual radical concentration in a fast equilibrium reaction [35][36][37]. This controlled polymerization should be advantageous for this work, compared to

• increased significantly to 50 and 45 kDa, indicating further polymerization and coinciding polyrotaxane formation. Starting from both polyHEMA and polyTRIS-AAm CTAs, monomer conversions were around 50%. For these block-copolymers with polyrotaxane middle blocks, the CD contents were 49 and 65 wt % of RAMEB

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• 2AZ, UK 10.3762/bjoc.12.205 Abstract The microstructure of the active blend layer has been shown to be a critically important factor in the performance of organic solar devices. Block copolymers provide a potentially interesting avenue for controlling this active layer microstructure in solar cell

• blends. Here we explore the impact of backbone fluorination in block copolymers of poly(3-octyl-4-fluorothiophene)s and poly(3-octylthiophene) (F-P3OT-b-P3OT). Two block co-polymers with varying block lengths were prepared via sequential monomer addition under Kumada catalyst transfer polymerisation

• thin-film microstructure playing such a key role in the optoelectronic and charge transport properties of conjugated polymers, block copolymers naturally appear as useful tools for tailoring the thin-film morphology [1][2][3][4][5]. The propensity of some block copolymers to phase segregate at the nano

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• biologically relevant type of new homopolymers (e.g., 2, Scheme 1) and block copolymers provided with amidoferrocenyl groups linked through a tetraethylene glycol side chain. These interesting metallopolymers were readily prepared through living ROMP initiated by the Grubbs 3rd generation catalyst which proved

• quite active and tolerant toward the monomer endowed with multiple functionalities (Scheme 1). By precisely controlling the living polymerization process, they succeeded in varying the number of amidoferrocenyl motifs in the polymers within pre-established limits. Such polymers and block copolymers were

• used to prepare modified Pt electrodes with high stability and good qualitative sensing of ATP2− anions. It was supposed that the triethylene glycol domains in the block copolymers favor the amidoferrocene–ATP interactions by encapsulation. Astruc assumed that during the recognition process different H

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• been employed in view to reduce these undesirable effects, e.g., the synthesis of copolymers [14][15][16][17], block copolymers [18], the introduction of donor (D) and acceptor (A) moieties [19][20][21], or bulky substituents at the C-9 position of the fluorene units [22][23][24], incorporating PF

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• performance is modest compared to that of similar devices fabricated using donor–acceptor block copolymers [88][89][90]. Nevertheless, the value of the PCE (0.31%) is higher than one would expect from a SMOSC fabricated from polymer 48 as a semiconductor, since it has no obvious donor–acceptor phase

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

• [69], magnetic core-shell nanoparticles (with magnetite cores and polyacrylate shells) [70], and thermoresponsive block copolymers [71]. Such catalytic systems can exhibit excellent organocatalytic activity under aqueous conditions, and many of them can be recycled and reused. A rather unique property

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

• diblock PEO–PPO copolymer chains attached to a central ethylenediamine group [8]. Their sensitivity to pH due to the central group offers interesting features as compared with the micelles of non-ionic block copolymers (such as Pluronics). Namely, with respect to the development of pharmaceutical

Linear-g-hyperbranched and cyclodextrin-based amphiphilic block copolymer as a multifunctional nanocarrier

• Yamei Zhao,
• Wei Tian,
• Guang Yang and
• Xiaodong Fan

Beilstein J. Org. Chem. 2014, 10, 2696–2703, doi:10.3762/bjoc.10.284

• contrast properties, raising increasing attention [3][6][7][9][10][11][12][13][14]. Compared with other multifunctional nanocarriers reported in the literature, polymeric micelles formed by amphiphilic block copolymers (ABC) may possess many advantages including water-solubility, nontoxicity, selectivity

• and LC values of the amphiphilic, linear-hyperbranched, block copolymers were higher than those of the amphiphilic, linear block copolymers with similar copolymer composition. UV–vis spectrophotometry was employed to confirm the multiregion encapsulation ability of theamphiphilic polymers [30]. Figure

• a result, DLMP2 had a stronger sustained release behaviour than DLMP1. Other researchers also proved that the amphiphilic, linear-hyperbranched, block copolymers had more sustained drug release behavior than those of amphiphilic, linear block copolymers [21]. Furthermore, the β-CD moieties of the

Loose-fit polypseudorotaxanes constructed from γ-CDs and PHEMA-PPG-PEG-PPG-PHEMA

• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2014, 10, 2461–2469, doi:10.3762/bjoc.10.257

• knowledge, self-assembled PPRs from γ-CDs with the bulkier poly(2-hydroxyethyl methacrylate) (PHEMA)-flanked block copolymers have not yet been reported. Herein, a pentablock copolymer PHEMA-PPO-PEO-PPO-PHEMA is prepared via atom transfer radical polymerization (ATRP) in DMF, and allowed to self-assemble

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• another with twin vinyl acetate oligomeric chains (AO-Vac, Table 1, compound 15). Polymers: Amphiphilic block-copolymers are classic examples of molecules which have an inherent ability to adsorb at interfaces and generate aggregation structures. Polymeric micelles may be generated in water and have been

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• Al or Cr(III) complexes also generated block copolymers in PO/CO2/PA terpolymerizations [30]. The terpolymerizations of CHO/CO2/PA and PO/CO2/maleic anhydride using a zinc glutarate catalyst have also been reported, where random copolymers containing some ether linkages were generated [28][31]. When

End-group-functionalized poly(N,N-diethylacrylamide) via free-radical chain transfer polymerization: Influence of sulfur oxidation and cyclodextrin on self-organization and cloud points in water

• Sebastian Reinelt,
• Daniel Steinke and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 680–691, doi:10.3762/bjoc.10.61

• of thermo-responsive micelles of end-group functionalized respectively block copolymers in aqueous solution have been investigated in previous studies [35][48][49]. Studies on hydrophobically PNIPAM have also demonstrated the formation of core-shell structures exhibiting a corona of PNIPAM chains [25