Benign coupling of reactions and separations with reversible ionic liquids

Hart, Ryan; Pollet, Paméla; Hahne, Dominique Julia; John, Ejae; Llopis-Mestre, Verónica; Blasucci, Vittoria; Huttenhower, Hillary; Leitner, Walter; Eckert, Charles A.; Liotta, Charles L.

doi:10.1016/j.tet.2009.11.014

Cited by 75 publications

(50 citation statements)

References 55 publications

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“…The Claisen-Schmidt condensation of butanone and benzaldehyde in RevIL system (TMBG/MeOH) was reported by Hart et al [39] (Figure 7). Three products are formed upon reaction: the internal enone (3-methyl-4-phenyl-but-3-en-2-one), the terminal enone (1-phenyl-pent-1-en-3-one) and water.…”

Section: The Claisen-schmidt Condensationmentioning

confidence: 54%

Solvents for sustainable chemical processes

Pollet

Eckert

Liotta

2011

WIT Transactions on Ecology and the Environment

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Worldwide, socioeconomic strategies encourage -and may soon enforceindustrial sustainability. Therefore, innovative research and approaches must provide short and long term solutions to reach future legislative targets. For chemical processes, the development of solvents that facilitate reaction and subsequent product separation is paramount to secure economic competitivity while minimizing impact on the environment and energy consumption. Tunable and switchable solvents were developed to address synergistically reaction and separation. Tunable solvents change properties continuously upon application of an external stimulus. For example, organic aqueous solvents allow for the reaction to be homogeneously catalyzed followed by a simple and efficient heterogeneous separation of the product (commonly a heterogeneous catalysis attribute). Chemical processes mediated by water at or below the near critical range can also alleviate the shortcomings of current synthetic strategies (waste production and management, remediation costs). In contrast, switchable solvents change physical properties abruptly upon application of an external stimulus. Piperylene sulfone is one example and can provide a recyclable alternative for dipolar, aprotic solvents such as dimethylsulfoxide (DMSO). Solvents can accomplish more than heat and mass transfer; they can actively contribute to facilitate reaction and product separation while minimizing waste generation and energy consumption.

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Section: The Claisen-schmidt Condensationmentioning

confidence: 54%

Solvents for sustainable chemical processes

Pollet

Eckert

Liotta

2011

WIT Transactions on Ecology and the Environment

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“…Formentin and coworkers also reported the recyclability of the mixture of KOH and ionic liquid in the Knoevenagel reaction [72]. Indeed, it was previously reported that the mixture of homogeneous catalysts and ionic liquid solvents could be recycled and reused in several organic transformations [3, 6–8]. However, it should be emphasized that the homogeneous catalyst could not be separated from the mixture, and hence it could not be recovered in essentially pure form after being used in the reaction.…”

Section: Resultsmentioning

confidence: 99%

“…They exhibit several advantages such as negligible vapor pressure, excellent ability to dissolve organic compounds, ease of separation from products, and potential for recycling [6–8]. A variety of ionic liquids have been investigated, generally consisting of salts of organic cations, for example, tetraalkylammonium, alkylpyridinium, 1,3-dialkylimidazolium, tetraalkylphosphonium [2, 9].…”

Section: Introductionmentioning

confidence: 99%

Chitosan as a Renewable Heterogeneous Catalyst for the Knoevenagel Reaction in Ionic Liquid as Green Solvent

Phan

Nguyen

et al. 2012

ISRN Organic Chemistry

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The combination of chitosan as a renewable heterogeneous catalyst and ionic liquid as a “green” solvent was employed for the Knoevenagel reaction. The chitosan catalyst was characterized by various techniques, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and elemental analysis. Excellent conversions were achieved under mild conditions without the need for an inert atmosphere. There was no contribution from leached active species, and conversion was only being possible in the presence of the solid catalyst. The chitosan catalyst as well as the ionic liquid solvent could be recovered in essentially pure form after being used in the reaction, and each of them could be reused several times without a significant degradation in efficiency.

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“…In an extraction, the desired solute can be extracted from a solid matrix by the form of the SPS that is capable of dissolving the solute (Figure 6.7). This approach has been used for polymerization, 95 ClaiseneSchmidt condensation, 103 cyanosilylation, 104 Michael addition 104 and Heck coupling reactions. This has been demonstrated for the extraction of organic products such as soybean oil, 100 hemicellulose 101 and algae oil.…”

Section: Switchable Polarity Solvents (Sps)mentioning

confidence: 99%

“…After filtration or decantation has removed the solid matrix, the SPS is switched into the other form, causing precipitation of the product. 104,105 When used as reaction media, SPS are sometimes called reversible ionic liquids (RIL). 102 SPS are useful as media for reactions as they provide a means by which the product can be separated from the solvent.…”

Section: Switchable Polarity Solvents (Sps)mentioning

confidence: 99%