Mild and efficient conversion of aldehydes to gem-diacetates using 2nd generation ionic liquids

Yadav, J. S.; Reddy, B. V. Subba; Sreedhar, P.; Kondaji, G.; Nagaiah, K.

doi:10.1016/j.catcom.2007.02.031

Cited by 20 publications

(9 citation statements)

References 30 publications

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“…[2] Many papers have outlined the advantages in terms of reaction rate, temperature, yield and selectivity when they are used as reaction media. [3] ILs have been frequently considered along the same lines as conventional organic solvents [4] and in a few cases as molten salts. [5] However, in the last few years a very interesting property of ILs has been emphasised.…”

Section: Introductionmentioning

confidence: 99%

Geminal Ionic Liquids: A Combined Approach to Investigate Their Three‐Dimensional Organisation

D’Anna

Ferrante

Noto

2009

Chemistry A European J

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Different investigations, such as 1D and 2D NMR spectroscopy, resonance light scattering spectroscopy and molecular dynamics simulations, have been jointly used to achieve a deeper understanding of the degree of structural order in two geminal ionic liquids. In particular, 3,3'-di-n-butyl-1,1'-(1,3-phenylenedimethylene)diimidazolium and 3,3'-di-n-butyl-1,1'-(1,4-phenylenedimethylene)diimidazolium bis[bis(trifluoromethanesulfonyl)imide] have been studied. These geminal ionic liquids were chosen because of the presence of both a rigid phenylenedimethylene link between two imidazolium rings, which should give a high degree of order to the solvent system, and the different shapes of the two cations of the isomers, which could induce different properties and packing in the liquid state. Data collected here show that the two geminal ionic liquids are characterised by a different degree of structural order that induces, for example, a different sensitivity of the two solvent systems to temperature changes or to the presence of a co-solvent such as methanol.

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Section: Introductionmentioning

confidence: 99%

Geminal Ionic Liquids: A Combined Approach to Investigate Their Three‐Dimensional Organisation

D’Anna

Ferrante

Noto

2009

Chemistry A European J

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“…Aldehydes can be protected as acylals (1,1-diacetates), which are stable compounds in basic and neutral media and easily re-converted into parent aldehydes [ 6 ]. In general, 1,1-diacetates are prepared from aldehydes by treatment with acetic anhydride using homogeneous catalysts [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. The methods mentioned above are not entirely satisfactory, owing to the problems of corrosion, tedious work-up, environmental pollution and non recoverable catalysts.…”

Section: Introductionmentioning

confidence: 99%

Sulphated Zirconia as an Eco-Friendly Catalyst in Acylal Preparation under Solvent-Free Conditions, Acylal Deprotection Assisted by Microwaves, and the Synthesis of Anhydro-Dimers of o-Hydroxybenzaldehydes

Palacios-Grijalva¹,

Cruz-González²,

Lomas‐Romero³

et al. 2009

Molecules

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A solvent-free approach is described for the regioselective synthesis of acylals (1,1-diacetates) in shorter reaction times and higher yields, compared to conventional methodology using solvents. In the protection reaction of the o-hydroxybenzaldehyde the formation of acetyl compounds and anhydro-dimers was observed. The deprotection reaction involves microwave (MW) exposure of diluted reactants in the presence of solid sulphated zirconia (SZ) catalyst that can be easily recovered and reused. The sulphated zirconia was recycled several times without any loss of activity.

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“…The high number of possible cation−anion combinations allows us to modulate the properties of these solvents, as a function of the target reaction. As a consequence, ILs frequently affect the outcome of a reaction, giving yields and selectivities higher than molecular solvents, under mild conditions too …”

Section: Introductionmentioning

confidence: 99%

Ionic Liquids/[bmim][N₃] Mixtures: Promising Media for the Synthesis of Aryl Azides by S_NAr

2008

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The nucleophilic aromatic substitution of some activated aryl or heteroaryl halides has been performed in ionic liquid solution, using the 1-butyl-3-methylimidazolium azide as a nucleophile. The reaction course was studied varying the structures of both substrates and ionic liquids. In particular, in the latter case, the reaction of 2-bromo-5-nitrothiophene was carried out in five different ionic liquids ([bmim][BF 4], [bmim][PF 6], [bmim][NTf 2], [bm 2im][NTf 2], and [bmpyrr][NTf 2]). Finally, for all the substrates considered, a comparison with data obtained in MeOH solution in the presence of NaN 3 was also performed. Data collected indicate that in some cases it is possible to obtain aromatic or heteroaromatic azide derivatives in satisfactory yield by means of a S NAr reaction using [bmim][N 3] as the nucleophile.

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Mild and efficient conversion of aldehydes to gem-diacetates using 2nd generation ionic liquids

Cited by 20 publications

References 30 publications

Geminal Ionic Liquids: A Combined Approach to Investigate Their Three‐Dimensional Organisation

Geminal Ionic Liquids: A Combined Approach to Investigate Their Three‐Dimensional Organisation

Sulphated Zirconia as an Eco-Friendly Catalyst in Acylal Preparation under Solvent-Free Conditions, Acylal Deprotection Assisted by Microwaves, and the Synthesis of Anhydro-Dimers of o-Hydroxybenzaldehydes

Ionic Liquids/[bmim][N₃] Mixtures: Promising Media for the Synthesis of Aryl Azides by S_NAr

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Mild and efficient conversion of aldehydes to gem-diacetates using 2nd generation ionic liquids

Cited by 20 publications

References 30 publications

Geminal Ionic Liquids: A Combined Approach to Investigate Their Three‐Dimensional Organisation

Geminal Ionic Liquids: A Combined Approach to Investigate Their Three‐Dimensional Organisation

Sulphated Zirconia as an Eco-Friendly Catalyst in Acylal Preparation under Solvent-Free Conditions, Acylal Deprotection Assisted by Microwaves, and the Synthesis of Anhydro-Dimers of o-Hydroxybenzaldehydes

Ionic Liquids/[bmim][N3] Mixtures: Promising Media for the Synthesis of Aryl Azides by SNAr

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Ionic Liquids/[bmim][N₃] Mixtures: Promising Media for the Synthesis of Aryl Azides by S_NAr