Improved catalysis of Morita–Baylis–Hillman reaction. The strong synergic effect using both an imidazolic ionic liquid and a temperature

Porto, Ricardo Silva; Amarante, Giovanni W.; Cavallaro, Mayra; Poppi, Ronei J.; Coelho, Fernando

doi:10.1016/j.tetlet.2008.12.089

Cited by 28 publications

(10 citation statements)

References 30 publications

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“…Furthermore, the use of ultrasound increased the yields up to 82% and decreased reaction times to 30 min at 0 °C. However, the diastereoselectivity was low (65:35 anti : syn in all the cases) [ 39 ], as depicted in Scheme 23 .…”

Section: Reaction Times Yield and Stereochemistry Of Mbh Reactionmentioning

confidence: 99%

The Morita-Baylis-Hillman Reaction: Insights into Asymmetry and Reaction Mechanisms by Electrospray Ionization Mass Spectrometry

2009

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This short review presents new insights on the mechanism and online monitoring using electrospray ionization tandem mass spectrometry (ESI-MS/MS) of Morita-Baylis-Hillman (MBH) reactions. MBH reactions are versatile carbon-carbon organocatalyzed bond forming reactions, making them environmentally friendly due to general organocatalysts employed. The organocatalyst behavior, which controls the transition state and thus the enantioselectivities in the obtained products, is very important in the performance of asymmetric MBH transformations. Some recent techniques and advances in asymmetric transformations are reviwed, as well as online reaction monitoring and analysis of the reaction intermediates. The mechanism accepted nowadays is also review through the insights gained from the use of ESI-MS/MS techniques.

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Section: Reaction Times Yield and Stereochemistry Of Mbh Reactionmentioning

confidence: 99%

The Morita-Baylis-Hillman Reaction: Insights into Asymmetry and Reaction Mechanisms by Electrospray Ionization Mass Spectrometry

2009

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“…Substrates having α‐ and, especially, β‐substituents require more forcing reaction conditions, and attempts to involve them in phosphine‐catalyzed transformations under normal temperature or pressure are usually unsuccessful . A number of methods have also been developed to improve the rate of the Morita–Baylis–Hillman reaction using microwave and ultrasound irradiation, Lewis acids , protic additives , ionic liquids , etc. Another promising strategy is based on the concept of hydrogen bonding, when substrates or catalysts are functionalized in a specific manner by proton‐donor groups .…”

Section: Introductionmentioning

confidence: 99%

Effect of Anchimeric Assistance in the Reaction of Triphenylphosphine with α,β‐Unsaturated Carboxylic Acids

Salin

Fatkhutdinov

Il'in

et al. 2014

Int J of Chemical Kinetics

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Quaternization of triphenylphosphine with maleic and cis-aconitic acids is strongly accelerated by participation of the cis-carboxyl group in stabilization of the phosphonium zwitterion intermediate by intramolecular hydrogen bonding, in spite of steric hindrance by the acid's reaction center. A similar effect for trans-isomeric acids is not observed, which can be rationalized on the basis of spatial structures of the generated zwitterions, implying an electrostatic interaction between the phosphonium center and carbonyl oxygen atom. The effect of anchimeric assistance decreases when the intramolecular hydrogen bonding disfavors attack of the phosphine on the sterically less hindered carbon atom of the C=C bond, as observed for cis-aconitic acid. C

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“…2 This reaction gave a mixture of diastereoisomers (1:5), which was directly treated with TBSCl/Imidazole to give the corresponding silyl ethers. After protection, the diastereoisomers are easily separated by column chromatography.…”

Section: Resultsmentioning

confidence: 99%

“…So, a solution of 3 in MeOH was treated at -78 ºC, with a flush of O 3 temperature for 15 min. After that the reaction was treated with S(Me) 2 and NH 4 OH.HCl in the presence of pyridine to give oxime 4, in 85% yield (over 2 steps). Although, we have observed a mixture of diastereoisomeric oximes no separation was provided in this step.…”

Section: Resultsmentioning

confidence: 99%

An expeditious approach to (+)-polyoxamic acid and derivatives from asymmetric Morita-Baylis-Hillman reaction.

Guidotti¹,

Correia²,

Ullah³

et al. 2013

Proceedings of the 15th Brazilian Meeting on Organic Synthesis Proceedings

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Improved catalysis of Morita–Baylis–Hillman reaction. The strong synergic effect using both an imidazolic ionic liquid and a temperature

Cited by 28 publications

References 30 publications

The Morita-Baylis-Hillman Reaction: Insights into Asymmetry and Reaction Mechanisms by Electrospray Ionization Mass Spectrometry

The Morita-Baylis-Hillman Reaction: Insights into Asymmetry and Reaction Mechanisms by Electrospray Ionization Mass Spectrometry

Effect of Anchimeric Assistance in the Reaction of Triphenylphosphine with α,β‐Unsaturated Carboxylic Acids

An expeditious approach to (+)-polyoxamic acid and derivatives from asymmetric Morita-Baylis-Hillman reaction.

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