SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• minimized diazide formation. Next, a solvent screening was performed as it can vastly influence reaction proceeding via a carbocation intermediate. Alkynyltrifluoroborates have a low solubility in chlorinated solvents but are well soluble in acetonitrile. Although this solvent has been used in similar

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• ). The complexes were obtained in high yields (>95%). The copper complexes were air and moisture-stable as solids but decomposed in chlorinated solvents after several days. It may be mentioned that Cu(I) halide and pseudohalide complexes with NHCs Me2L, Et2L and AdL were prepared from direct reaction of

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• 5.44 in MeOH) [22] the formation of thiazole/thiazol-4-one (XI/XIII) is clearly preferred, whereas reactions in common chlorinated solvents (CH2Cl2, CHCl3) containing either an equivalent of strong base (methoxide) or excess of medium base in heterogeneous system (e.g., carbonate with pKa = 9.93 in

• ; entry 10 in Table 1) only decreased the combined yield of 8a and 8a-Me, but no ECR product 9a was detected. The change of polar aprotic to chlorinated solvents (DCM, CHCl3) as recommended by Eschenmoser [23] leads to ambiguous results. In amylene-stabilized CHCl3 at 55 °C and with 3 equivalents of solid

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• which oxalyl chloride was added at room temperature, and then reacted with aluminium trichloride at 0 °C. The resulting material was not soluble in cold dichloromethane/chloroform, but was found to be sufficiently soluble in hot chlorinated solvents. NMR spectroscopy in deuterated DMSO indicated that

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

• ). To further optimise the reaction, we screened different solvents (apolar, polar aprotic, and chlorinated solvents) (Table 1, entries 5–7). According to the obtained results chloroform was clearly superior to other solvents. Previously the isolated yield of the product had been moderate and to

Iodine-catalyzed electrophilic substitution of indoles: Synthesis of (un)symmetrical diindolylmethanes with a quaternary carbon center

• Thanigaimalai Pillaiyar,
• Masoud Sedaghati,
• Andhika B. Mahardhika,
• Lukas L. Wendt and
• Christa E. Müller

Beilstein J. Org. Chem. 2021, 17, 1464–1475, doi:10.3762/bjoc.17.102

• employing indoles bearing bulky substituents at their 2-position (Ling et al.), or the need for chlorinated solvents (Sasaki et al.), as well as difficulty to scale up the reactions to a multigram scale, as well as a generally rather limited substrate scope. Therefore, finding a robust method with a broad

• to the synthesis of pentafluoroethylated and heptafluoropropylated-DIMs. It constitutes an important addition to the active field of DIM syntheses facilitating the preparation of unsymmetrical quaternary DIMs without the need for chlorinated solvents, high temperatures, or heavy-metal catalysts. A

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• packaging, squeezable bottles, plastic bags and medical devices [140]. PEs (except cross-linked samples) are partially soluble in (hot) aromatic hydrocarbons or in chlorinated solvents [141]. Depolymerisation of PE by catalytic pyrolysis or cracking into liquid fuels was recently reviewed [67][142]. Most of

• alkali bases and chlorinated solvents [176][177], which makes them neither economically competitive nor environmentally friendly [178][179]. A survey of patents related to the chemical recycling of PET up to 2005 can be found in the literature [180]. Hydrogenolysis. In the recent years, hydrogenolysis

Using multiple self-sorting for switching functions in discrete multicomponent systems

• Amit Ghosh and
• Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

• . Interestingly, the fullerene C60 was not taken up as a guest by the tetramer (6)4 in chlorinated solvents. For a more defined self-sorting, the authors switched the solvent from CDCl3 to [d8]-toluene. Now, a 2-fold completive self-sorting delivered the homoleptic inclusion complexes [(5)4(C60)] and [(6)4(C60

Fluorohydration of alkynes via I(I)/I(III) catalysis

• Jessica Neufeld,
• Constantin G. Daniliuc and
• Ryan Gilmour

Beilstein J. Org. Chem. 2020, 16, 1627–1635, doi:10.3762/bjoc.16.135

• ). Having established that an amine/HF ratio of 1:7.5 provides the optimal Brønsted acidity for catalysis, a solvent screen was conducted to assess the effect of the reaction medium. Chlorinated solvents proved to be most effective, with reactions performed in CHCl3 slightly outperforming those in CH2Cl2

Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• of molecular oxygen as an oxidant. Although various photoredox catalysts and solvents were examined, the best results were obtained with photoredox catalyst 6 in chlorinated solvents. In the absence of a photoredox catalyst, the goup did not observe any product formation. A list of products assembled

Probing of local polarity in poly(methyl methacrylate) with the charge transfer transition in Nile red

• Aydan Yadigarli,
• Qimeng Song,
• Sergey I. Druzhinin and
• Holger Schönherr

Beilstein J. Org. Chem. 2019, 15, 2552–2562, doi:10.3762/bjoc.15.248

• and in chlorinated solvents lie also clearly below the straight line in Figure 3a. This is tentatively attributed to the different inductive solute–solvent interactions, which are neglected in Equation 1. Such additional red shift in the case of halogenated solvents has been explained before by the

• high stability also in the chlorinated solvents, cf. with a lack of a red edge effect for 4-fluoro-N,N-dimethylaniline [67]. On the other hand, when the relaxation time of the molecules or segments (τr) of the polymer matrix is much longer than the NR fluorescence decay time τf = 3.87 ns [62] in PMMA

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• nitrate complex was thus soluble in chlorinated solvents. In the presence of the bulky triphenylphosphine silver triflate salt, a monocoordination occurred between Ag(I) and each sulfur atom of ligand 1 leading to a discrete complex (syn-1)·(Ph3PAgOTf)2, as revealed by 1H NMR and X-ray (Figure 3). The

Mechanochemical synthesis of hyper-crosslinked polymers: influences on their pore structure and adsorption behaviour for organic vapors

• Sven Grätz,
• Sebastian Zink,
• Hanna Kraffczyk,
• Marcus Rose and
• Lars Borchardt

Beilstein J. Org. Chem. 2019, 15, 1154–1161, doi:10.3762/bjoc.15.112

• suitable alternative in the synthesis of hyper-crosslinked polymers. By avoiding chlorinated solvents (typically 1,2-dichloroethane), the synthesis of this promising material can be undertaken in a greener, faster, and cheaper fashion. The obtained materials show surface areas as high as 1720 m2g−1 with a

Extending mechanochemical porphyrin synthesis to bulkier aromatics: tetramesitylporphyrin

• Qiwen Su and
• Tamara D. Hamilton

Beilstein J. Org. Chem. 2019, 15, 1149–1153, doi:10.3762/bjoc.15.111

• porphyrins are synthesized through a four-fold acid-catalyzed condensation to form a porphyrinogen which is then oxidized (− 6H) to form the conjugated porphyrin product. Lindsey’s reaction takes place at room temperature and utilizes chlorinated solvents under optimized dilution conditions (10−2 M reactant

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

• transformations occurring in thin layers of PDCPD during oxidation in air. Polymers obtained during the dicyclopentadiene polymerization under these conditions are well soluble in aromatic and chlorinated solvents, and from these solutions, smooth transparent films can be produced. However, the surface of PDCPD

Gold-catalyzed post-Ugi alkyne hydroarylation for the synthesis of 2-quinolones

• Xiaochen Du,
• Jianjun Huang,
• Anton A. Nechaev,
• Ruwei Yao,
• Jing Gong,
• Erik V. Van der Eycken,
• Olga P. Pereshivko and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2018, 14, 2572–2579, doi:10.3762/bjoc.14.234

• -dimethoxyaniline (6a). Next, the cycloisomerization of 7a was investigated in order to identify the optimal conditions. At first, we attempted two reactions using 5 mol % of the standard AuPPh3Cl/AgOTf precatalytic combination in conventional chlorinated solvents such as deuterated chloroform and dichloromethane

• ). Conducting the AuPPh3Cl/AgOTf-catalyzed reaction in trifluoroethanol (TFE) led to improved results producing 8a in up to 97% yield (Table 1, entry 6). Thus, this greener alternative [63] to chlorinated solvents was selected as the solvent of choice for the further exploration. Changing the silver counterpart

Asymmetric α-amination of 3-substituted oxindoles using chiral bifunctional phosphine catalysts

• Qiao-Wen Jin,
• Zhuo Chai,
• You-Ming Huang,
• Gang Zou and
• Gang Zhao

Beilstein J. Org. Chem. 2016, 12, 725–731, doi:10.3762/bjoc.12.72

• influence of solvents and reaction temperature on the reaction were investigated with the best catalyst (Table 2). The use of both polar solvents (ethyl ether, tetrahydrofuran, acetone, acetonitrile or ethyl alcohol) including other chlorinated solvents such as chloroform, 1,2-dichloroethane and 1,1,2

Copper-catalysed asymmetric allylic alkylation of alkylzirconocenes to racemic 3,6-dihydro-2H-pyrans

• Emeline Rideau and
• Stephen P. Fletcher

Beilstein J. Org. Chem. 2015, 11, 2435–2443, doi:10.3762/bjoc.11.264

• electron withdrawing counterions were found to provide the desired product, with CuClO4 giving the best ee (70% ee, Table 1, entry 3). A solvent screen lead us to the conclusion that chlorinated solvents are best (CH2Cl2 (70% ee) and CHCl3 (67% ee), Table 1, entries 7 and 10, respectively). Extensive

Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions

• Shawna L. Balof,
• K. Owen Nix,
• Matthew S. Olliff,
• Sarah E. Roessler,
• Arpita Saha,
• Kevin B. Müller,
• Ulrich Behrens,
• Edward J. Valente and
• Hans-Jörg Schanz

Beilstein J. Org. Chem. 2015, 11, 1960–1972, doi:10.3762/bjoc.11.212

• , ether, THF and acetone. Chlorinated solvents such as CH2Cl2 and CHCl3 dramatically improve the complex solubility but have shown to result in significant degradation over a period of several hours. An NMR sample of complex 12 in CDCl3 exhibited approx. 10% decomposition over a 24 h period at room

Site-selective covalent functionalization at interior carbon atoms and on the rim of circumtrindene, a C₃₆H₁₂ open geodesic polyarene

• Hee Yeon Cho,
• Ronald B. M. Ansems and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2014, 10, 956–968, doi:10.3762/bjoc.10.94

• circumtrindene might also be brominated. Fullerenes are known to undergo bromine addition with elemental bromine in chlorinated solvents at room temperature [28]. To avoid the unwanted bromination at interior carbon atoms, the reaction conditions were carefully optimized (see Supporting Information File 1 for

Primary-tertiary diamine-catalyzed Michael addition of ketones to isatylidenemalononitrile derivatives

• Akshay Kumar and
• Swapandeep Singh Chimni

Beilstein J. Org. Chem. 2014, 10, 929–935, doi:10.3762/bjoc.10.91

• solvents, such as 1,4-dioxane and methyl tert-butyl ether (MTBE), provided Michael adduct 4a in 89% and 90% yield and 89% ee and 87% ee, respectively (Table 1, entries 4 and 5). In toluene, 4a was obtained in 89% yield and 90% ee (Table 1, entry 6). The chlorinated solvents such as dichloromethane

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

• ]. Besides the mixed solvents, gelation and partial gelation also occurred in ethylene glycol (entry 12, Table 1) and acetonitrile (entry 13, Table 1). In aromatic solvents (entries 14 and 15, Table 1), chlorinated solvents (entries 16 and 17, Table 1) and low molecular weight alcohols (entries 18 and 19

Modulating NHC catalysis with fluorine

• Yannick P. Rey and
• Ryan Gilmour

Beilstein J. Org. Chem. 2013, 9, 2812–2820, doi:10.3762/bjoc.9.316

• enantioselectivity (Table 1, entries 2–8). Chlorinated solvents such as CH2Cl2 and CDCl3 (Table 1, entries 2 and 3) led to losses in enantioselectivity, whilst THF completely suppressed the reaction (Table 1, entry 4, <1% conversion). Intriguingly, switching from THF to Et2O (Table 1, entry 5) resulted in full

Gold-catalyzed intermolecular coupling of sulfonylacetylene with allyl ethers: [3,3]- and [1,3]-rearrangements

• Jungho Jun,
• Hyu-Suk Yeom,
• Jun-Hyun An and
• Seunghoon Shin

Beilstein J. Org. Chem. 2013, 9, 1724–1729, doi:10.3762/bjoc.9.198

• = di-t-butyl-o-biphenylphosphine, JohnPhos) formed in situ was used as catalyst, the reaction was more efficient in chlorinated solvents rather than polar aprotic or aromatic hydrocarbon solvents (Table 1, entries 1–7). Contrary to the previous [4 + 2] cycloaddition, formal enyne cross metathesis or [2

Coupling of C-nitro-NH-azoles with arylboronic acids. A route to N-aryl-C-nitroazoles

• Marta K. Kurpet,
• Aleksandra Dąbrowska,
• Małgorzata M. Jarosz,
• Katarzyna Kajewska-Kania,
• Nikodem Kuźnik and
• Jerzy W. Suwiński

Beilstein J. Org. Chem. 2013, 9, 1517–1525, doi:10.3762/bjoc.9.173

• arylboronic acids and substituted C-nitroazole coupling, applying the conditions described for the Chan–Lam reaction. This involves the use of chlorinated solvents, pyridine as base, and prolonged reaction times to obtain high yields of the product [28][29]. No detailed investigation on the influence of the