Diels-Alder reactions in room-temperature ionic liquids
TL;DR: The Diels-Alder cycloaddition reaction between methyl acrylate and cyclopentadiene has been investigated in a number of air and moisture stable ionic liquids as discussed by the authors.
About: This article is published in Tetrahedron Letters.The article was published on 1999-01-22. It has received 377 citations till now. The article focuses on the topics: Ionic liquid & Methyl acrylate.
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12,178 citations
TL;DR: There are indications that switching from a normal organic solvent to an ionic liquid can lead to novel and unusual chemical reactivity, which opens up a wide field for future investigations into this new class of solvents in catalytic applications.
Abstract: Ionic liquids are salts that are liquid at low temperature (<100 degrees C) which represent a new class of solvents with nonmolecular, ionic character. Even though the first representative has been known since 1914, ionic liquids have only been investigated as solvents for transition metal catalysis in the past ten years. Publications to date show that replacing an organic solvent by an ionic liquid can lead to remarkable improvements in well-known processes. Ionic liquids form biphasic systems with many organic product mixtures. This gives rise to the possibility of a multiphase reaction procedure with easy isolation and recovery of homogeneous catalysts. In addition, ionic liquids have practically no vapor pressure which facilitates product separation by distillation. There are also indications that switching from a normal organic solvent to an ionic liquid can lead to novel and unusual chemical reactivity. This opens up a wide field for future investigations into this new class of solvents in catalytic applications.
5,387 citations
TL;DR: The current state of the art of the application of ionic liquids in catalysis is reviewed in this article, where examples of the different ways in which ionic liquid have been applied in Catalysis, i.e. as the catalyst itself, as a co-catalyst or catalyst activator, as the source of a new ligand for a catalytic metal centre, or just as the solvent for the reaction.
1,423 citations
TL;DR: This critical review will assess the greenness and sustainability of IL processing of biomass, where it would seem that the choices of cation and anion are critical not only to the science of the dissolution, but to the ultimate 'greenness' of any process.
Abstract: Utilization of natural polymers has attracted increasing attention because of the consumption and over-exploitation of non-renewable resources, such as coal and oil. The development of green processing of cellulose, the most abundant biorenewable material on Earth, is urgent from the viewpoints of both sustainability and environmental protection. The discovery of the dissolution of cellulose in ionic liquids (ILs, salts which melt below 100 °C) provides new opportunities for the processing of this biopolymer, however, many fundamental and practical questions need to be answered in order to determine if this will ultimately be a green or sustainable strategy. In this critical review, the open fundamental questions regarding the interactions of cellulose with both the IL cations and anions in the dissolution process are discussed. Investigations have shown that the interactions between the anion and cellulose play an important role in the solvation of cellulose, however, opinions on the role of the cation are conflicting. Some researchers have concluded that the cations are hydrogen bonding to this biopolymer, while others suggest they are not. Our review of the available data has led us to urge the use of more chemical units of solubility, such as ‘g cellulose per mole of IL’ or ‘mol IL per mol hydroxyl in cellulose’ to provide more consistency in data reporting and more insight into the dissolution mechanism. This review will also assess the greenness and sustainability of IL processing of biomass, where it would seem that the choices of cation and anion are critical not only to the science of the dissolution, but to the ultimate ‘greenness’ of any process (142 references).
1,090 citations
TL;DR: A review of the potential applications of these unique liquid materials in industrial catalysis can be found in this paper, where the use of room temperature ionic liquids as either solvents or catalysts has been the subject of considerable recent attention.
983 citations
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TL;DR: Alkylation et acylation du benzene en utilisant des melanges de chlorure de methyl-1 ethyl-3 imidazolium avec AlCl 3 a la fois comme solvants and comme catalyseurs as discussed by the authors.
Abstract: Alkylation et acylation du benzene en utilisant des melanges de chlorure de methyl-1 ethyl-3 imidazolium avec AlCl 3 a la fois comme solvants et comme catalyseurs
449 citations
TL;DR: The use of the Diels-Alder reaction between methyl acrylate and cyclopentadiene as a chemical probe has demonstrated two distinct zones in the formamide microemulsion system as mentioned in this paper.
38 citations