Metal exchanged layered zirconium hydrogen phosphate as base catalyst of the Michael reaction

Costantino, U.; Marmottini, Fabio; Curini, Massimo; Rosati, Ornelio

doi:10.1007/bf00807241

Cited by 26 publications

(15 citation statements)

References 13 publications

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“…Other studies of the use of solid catalysts in the Michael additions of several nucleophiles, including a couple of examples with nitroalkanes, have been reported under KFalumina [71] or layered zirconium hydrogen phosphate catalysis [72].…”

Section: Michael Reaction Of Nitroalkanes Under Solid Catalysismentioning

confidence: 99%

Synthetic Applications of Nitroalkanes Promoted by Solid Catalysis: Recent Results

Ballini

Palmieri

2006

COC

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Solid catalysis is crucial to chemical technology. Innumerable chemical reactions are facilitated by this catalytic system and, in this context, nitroalkanes have been demonstrated a great reactivity under solid catalysis, especially in the formation of new carbon-carbon single bond. In fact, aliphatic nitrocompounds are a valuable source of stabilized carbanions since the high electron-withdrawing power of the nitro group provides an outstanding enhancement of the hydrogen acidity at the alpha-position (cf. pK(a) MeNO2 = 10). Nitronate anions, that can be generated from nitroalkanes, using a wide range of bases, act as carbon nucleophiles with common electrophiles such as aldehydes (Nitroaldol-Henry-reaction), and electron-poor alkenes (Michael reaction), leading to carbon-carbon bond formation. In the last few decades several solid catalyses have been efficiently proposed for the employment of the nitroalkanes in the latter reactions. Very often the use of nitroalkanes, combined with solid catalysis, offers the opportunity to perform the reactions more efficiently, with enhanced chemoselectivity, high purity, improved yields and without the use of any solvent

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Section: Michael Reaction Of Nitroalkanes Under Solid Catalysismentioning

confidence: 99%

Synthetic Applications of Nitroalkanes Promoted by Solid Catalysis: Recent Results

Ballini

Palmieri

2006

COC

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“…Furthermore the structure of these exchanged metal-phosphate materials may be determined at the atomic level. The potassium exchanged zirconium hydrogen phosphate Zr(O 3 POK) 2 has already been used as a basic catalyst for Michael addition, 7 Henry reaction, 8 cyanosilylation of carbonyl compounds 9 and more recently for the desilylation of phenol silyl ethers. 10 Zr(O 3 POK) 2 , is a layered material which possesses ionic oxygen pointing towards the interlayer space.…”

Section: Introductionmentioning

confidence: 99%

“…10 Zr(O 3 POK) 2 , is a layered material which possesses ionic oxygen pointing towards the interlayer space. This compound may be obtained either from zirconium hydrogen phosphate Zr(O 3 POH) 2 •H 2 O via an exchange with potassium hydroxide 7 or directly from a solidphase synthesis at high temperature. 11 The Knoevenagel condensation is a useful reaction for the generation of double bonds from a carbonyl compound and an active methylene compound.…”

Section: Introductionmentioning

confidence: 99%

Potassium exchanged zirconium hydrogen phosphate Zr(O3POK)2: a heterogeneous basic catalyst for Knoevenagel reaction without solvent

et al. 2001

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A simple work-up to prepare crystalline potassium exchanged zirconium hydrogen phosphate Zr(O 3 POK) 2 is proposed. In addition the synthesis of amorphous potassium exchanged zirconium hydrogen phosphate Zr(O 3 POK) 2 , obtained from an amorphous sample of Zr(O 3 POH) 2 •H 2 O is reported. All these exchanged materials Zr(O 3 POK) 2 are powerful catalysts for the Knoevenagel reaction. Furthermore the absence of solvent increases the rate of the reaction. Products can be separated from the catalyst by sublimation thus avoiding the use of solvent in the purification step. The catalyst, which is thus easily recovered, shows no appreciable loss of activity when recycled three times.

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“…The aim and novelty of the present manuscript was the fabrication of micro architectures on Zr via anodizing in phosphoric acid (H 3 PO 4 ) and the methodical investigation of the surface properties at various potential using a variety of methods and physical concepts. The surface analysis and compositions of films were correlated with the macrostructure properties able to induce their use in applications such as: drug delivery [10,11] catalysis [12] or nuclear waste management [13].…”

mentioning

confidence: 99%

The Evolution of Morphology and Properties of Films Obtained by Anodizing Zirconium

Ioniță¹,

Nicoara²,

Stoian³

2019

Rev. Chim.

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By anodizing zirconium in phosphoric acid at various potentials, different structures were obtained on the surfaces of the samples. The morphologies and compositions of the obtained coatings were investigated using scanning electronic microscopy (SEM), X-rays analysis (XRD) and Raman spectroscopy and were found to be dependent on anodizing potential. Electrochemical tests were performed in order to establish the stability of the samples. The film delamination forces increased with the anodizing potential, confirming that the zirconium dioxide film formed during anodizing becomes more resistant at higher potentials.

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Metal exchanged layered zirconium hydrogen phosphate as base catalyst of the Michael reaction

Cited by 26 publications

References 13 publications

Synthetic Applications of Nitroalkanes Promoted by Solid Catalysis: Recent Results

Synthetic Applications of Nitroalkanes Promoted by Solid Catalysis: Recent Results

Potassium exchanged zirconium hydrogen phosphate Zr(O3POK)2: a heterogeneous basic catalyst for Knoevenagel reaction without solvent

The Evolution of Morphology and Properties of Films Obtained by Anodizing Zirconium

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