1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• with alternative solvents could represent an important innovation for alkyne hydration. In particular, ionic liquids (ILs) could represent a valid alternative to conventional organic solvents. ILs are generally liquid salts at or near room temperature, formed by large unsymmetrical organic cations and

• presence of the NHC derived from the IL deprotonation. Conclusion In conclusion, in this work we demonstrated the possibility to carry out the hydration of alkynes in imidazolium ILs, as alternative solvents until now still little explored for this reaction, employing the Lewis acid BF3 as catalyst. The

Facile and innovative catalytic protocol for intramolecular Friedel–Crafts cyclization of Morita–Baylis–Hillman adducts: Synergistic combination of chiral (salen)chromium(III)/BF₃·OEt₂ catalysis

• Karthikeyan Soundararajan,
• Helen Ratna Monica Jeyarajan,
• Raju Subimol Kamarajapurathu and
• Karthik Krishna Kumar Ayyanoth

Beilstein J. Org. Chem. 2021, 17, 2186–2193, doi:10.3762/bjoc.17.140

• in MBH adduct 5a (Table 1, entries 14–17). Interestingly among all co-catalysts examined, boron trifluoride etherate was the found to be the suitable co-catalyst in accelerating the proposed reaction. Furthermore on screening the optimized catalytic combination in presence of alternative solvents

Nitroalkene reduction in deep eutectic solvents promoted by BH₃NH₃

• Chiara Faverio,
• Monica Fiorenza Boselli,
• Patricia Camarero Gonzalez,
• Alessandra Puglisi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2021, 17, 1041–1047, doi:10.3762/bjoc.17.83

• reproducible protocol to isolate the product without the use of any organic solvent was established, and the recyclability of the DES mixture was successfully investigated. Keywords: alternative solvents; atom economy; DES; nitro derivatives; reduction; Introduction The search for alternative solvents, not

• eutectic mixtures as biorenewable alternative solvents in the synthesis of nitroalkanes, valuable precursors of amines, would represent a significant step towards the development of more sustainable synthetic organic methodologies for the preparation of valuable molecules. In the present communication, we

• Information File 1). The DES was reused other three times with no appreciable difference in the yield. Conclusion In conclusion, the combination of an atom economically convenient and inexpensive reagent such as ammonia borane with bio-based and biorenewable alternative solvents such as deep eutectic mixtures

NHC-catalyzed enantioselective synthesis of β-trifluoromethyl-β-hydroxyamides

• Alyn T. Davies,
• Mark D. Greenhalgh,
• Alexandra M. Z. Slawin and
• Andrew D. Smith

Beilstein J. Org. Chem. 2020, 16, 1572–1578, doi:10.3762/bjoc.16.129

• observed, which served as a basis for further optimization. Variation of the base showed caesium carbonate to be significantly more effective than the organic bases examined, giving 88% conversion to product 6 (Table 1, entries 2 and 3). Trialling a number of alternative solvents, including dichloromethane

Suzuki–Miyaura cross coupling is not an informative reaction to demonstrate the performance of new solvents

• James Sherwood

Beilstein J. Org. Chem. 2020, 16, 1001–1005, doi:10.3762/bjoc.16.89

• Mizoroki–Heck reaction and hence there is also a motivation to investigate safer alternative solvents that the Suzuki–Miyaura reaction lacks. If researchers are still compelled to study the utility of solvents in the Suzuki–Miyaura reaction, I encourage future studies to be directed at challenging

Development of a continuous process for α-thio-β-chloroacrylamide synthesis with enhanced control of a cascade transformation

• Olga C. Dennehy,
• Valérie M. Y. Cacheux,
• Benjamin J. Deadman,
• Denis Lynch,
• Stuart G. Collins,
• Humphrey A. Moynihan and
• Anita R. Maguire

Beilstein J. Org. Chem. 2016, 12, 2511–2522, doi:10.3762/bjoc.12.246

• process scales caused us to consider alternative ‘greener’ solvent systems [27]. A screen of alternative solvents in batch test reactions revealed that, while the amide formation was tolerant to most solvents, rapid precipitation of triethylamine hydrochloride would be problematic in a continuous process

• (Table 2), around 20% of the starting material was consistently found to be unreacted. The key limitation to overcome was proposed to be the low solubility of NCS in toluene, and the consequent limitations to reactor throughput. To offset this difficulty, the use of alternative solvents was investigated

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• six-membered rings and only four articles described the synthesis of three and seven-membered heterocycles. Additionally, the majority of the reported syntheses were devoted to the development of new methodologies including the use of advanced catalytic systems, alternative solvents and microwave

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

• H. Surya Prakash Rao and
• A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

• ) [58][59][60] in 64% yield. To obtain the desired triphenylmethane (11a) as the sole product, we screened various alternative solvents (Scheme 2). Of the solvents investigated, toluene gave a mixture of triphenylmethane (11a) and the toluene-incorporated product (p-tolylmethylene)dibenzene (14) in 36

Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen

• Hans Sterckx,
• Johan De Houwer,
• Carl Mensch,
• Wouter Herrebout,
• Kourosch Abbaspour Tehrani and
• Bert U. W. Maes

Beilstein J. Org. Chem. 2016, 12, 144–153, doi:10.3762/bjoc.12.16

• extraction provided a much higher value, namely 1097 ppm. However, if after the extraction a recrystallization step of the reaction product is performed the Fe level can be lowered further to 300 ppm which is well below the legal limit for oral exposure (see Supporting Information File 1). Alternative

• solvents A solvent screening was subsequently performed focusing mainly on greener solvents than DMSO with a boiling point above 100 °C in order to allow a direct comparison at the same reaction temperature [44][45] (Table 4). All reactions were performed in a round-bottomed flask equipped with a reflux

An efficient synthesis of N-substituted 3-nitrothiophen-2-amines

• Sundaravel Vivek Kumar,
• Shanmugam Muthusubramanian,
• J. Carlos Menéndez and
• Subbu Perumal

Beilstein J. Org. Chem. 2015, 11, 1707–1712, doi:10.3762/bjoc.11.185

• carbonate as the optimal base in refluxing ethanol (93% yield), alternative solvents such as methanol (Table 1, entry 13), N,N-dimethylformamide (Table 1, entry 14), acetonitrile (Table 1, entry 15), tetrahydrofuran (Table 1, entry 16), 1,4-dioxane (Table 1, entry 17) and water (Table 1, entry 18) were

Synthesis of new enantiopure poly(hydroxy)aminooxepanes as building blocks for multivalent carbohydrate mimetics

• Léa Bouché,
• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 213–223, doi:10.3762/bjoc.10.17

• may be unfavorable. In order to avoid this side-reaction we performed hydrogenolysis experiments in alternative solvents, e.g. with ethanol or isopropanol, but small amounts of the corresponding side products were also observed in these experiments. Unpolar solvents were not suitable for the

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

Synthesis and ring openings of cinnamate-derived N-unfunctionalised aziridines

• Alan Armstrong and
• Alexandra Ferguson

Beilstein J. Org. Chem. 2012, 8, 1747–1752, doi:10.3762/bjoc.8.199

• screen of alternative solvents, tertiary amines and bases showed that NMM and NaOH in CH2Cl2 was the optimum reagent combination for the aziridination. Having optimised our aziridination protocol for tert-butyl cinnamate, our attention then turned to examining the scope for aromatic substitution in the

Efficient and selective chemical transformations under flow conditions: The combination of supported catalysts and supercritical fluids

• M. Isabel Burguete,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2011, 7, 1347–1359, doi:10.3762/bjoc.7.159

• provide simple tools for a rapid optimization of reaction parameters and facilitate the development of efficient flow processes [23][24][25]. Neoteric solvents (scFs, ionic liquids, PEG, etc.) have been considered as “green” alternative solvents due to their properties. However, in order to consider a

The development and evaluation of a continuous flow process for the lipase- mediated oxidation of alkenes

• Charlotte Wiles,
• Marcus J. Hammond and
• Paul Watts

Beilstein J. Org. Chem. 2009, 5, No. 27, doi:10.3762/bjoc.5.27

• source of acetic acid (1), from which the peracid 5 could be generated. It is however acknowledged that other solvents may be required and future work will therefore focus on the use of alternative solvents systems, employing a catalytic quantity of a carboxylic acid additive to generate the respective

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• have been developed recently, including processes using alternative solvents such as ionic liquids and/or scCO2 [56][57][58][59][60][61]. The kinetic resolution of racemic 1-phenylethanol 54 was performed continuously in scCO2, using an immobilized lipase (Candida antarctica, Novozym 435) and vinyl

Radical cascades using enantioenriched 7-azabenzonorbornenes and their applications in synthesis

• David M. Hodgson and
• Leonard H. Winning

Beilstein J. Org. Chem. 2008, 4, No. 38, doi:10.3762/bjoc.4.38

• sodium periodate as the stoichiometric oxidant and esterification using CH2N2 gave diester 35 (49%, 37% using Me3SiCHN2). Attempts to improve the procedure further by the use of alternative solvents proved unsatisfactory. Azacycle (+)-10, the product of deoxygenation-rearrangement-trapping with methyl

Study of thioglycosylation in ionic liquids

• Jianguo Zhang and
• Arthur Ragauskas

Beilstein J. Org. Chem. 2006, 2, No. 12, doi:10.1186/1860-5397-2-12

• five sequential glycosylation reactions with no impact on product yield. Owing to their unique chemical and physical properties, room temperature ionic liquids (ILs) have received significant attention as alternative solvents for a host of different applications. For example, it has been reported that

The oxanorbornene approach to 3-hydroxy, 3,4-dihydroxy and 3,4,5-trihydroxy derivatives of 2-aminocyclohexanecarboxylic acid

• Ishmael B. Masesane,
• Andrei S. Batsanov,
• Judith A. K. Howard,
• Raju Mondal and
• Patrick G. Steel

Beilstein J. Org. Chem. 2006, 2, No. 9, doi:10.1186/1860-5397-2-9

• alternative solvents were not successful. Interestingly, Just and co-workers have reported the preference for the exo-nitro adduct when the reaction of methyl 3-nitroacrylate and furan was carried out without a solvent.[16] However, in our hands, this reaction afforded a 3:1 mixture in favour of the endo

• polar solvents would lead to increased amounts of 12 a range of alternative solvents were screened including THF, DMF, MeOH, CF3CH2OH, MeCN. Of these, acetonitrile proving the most successful, albeit only providing a 2:1 mixture of isomers. Attempts to further enhance this reversal of selectivity using