scholarly journals Zr-SBA-15 Lewis Acid Catalyst: Activity in Meerwein Ponndorf Verley Reduction

Catalysts ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 1911-1927 ◽  
Author(s):  
Jose Iglesias ◽  
Juan Melero ◽  
Gabriel Morales ◽  
Jovita Moreno ◽  
Yolanda Segura ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Reaction Temperature ◽  
Catalyst Activity ◽  
Acid Catalyst ◽  
Positive Influence ◽  
Molar Ratio ◽  
Special Focus ◽  
Molar Ratios ◽  
Lewis Acid Catalyst

Zr-SBA-15 Lewis acid catalyst has demonstrated an outstanding catalytic activity in the reduction of several carbonyl compounds by means of Meerwein Ponndorf Verley (MPV) reaction, using several secondary alcohols, and showing a very high selectivity towards the desired products. Special focus was addressed in the catalytic activity of Zr-SBA-15 material in the production of furfuryl alcohol from furfural, which is an important reaction for the lignocellulosic biomass valorization. In this transformation, both the reaction temperature and the i-PrOH:Furfural molar ratio exert a positive influence on the rate of the MPV transformation, with the influence of the former being much higher. i-propyl-furfuryl ether, a by-product resulting from the etherification of the target product with the sacrificing alcohol, is also found together with the main product. The production of this side-product is highly influenced by the reaction temperature, so that low temperatures and high sacrificing alcohol to substrate molar ratios have to be applied to keep its production at low levels.

Post-synthetic metalation in an anionic MOF for efficient catalytic activity and removal of heavy metal ions from aqueous solution

2016 ◽  
Vol 52 (13) ◽  
pp. 2831-2834 ◽  
Author(s):  
Anindita Chakraborty ◽  
Sohini Bhattacharyya ◽  
Arpan Hazra ◽  
Ashta Chandra Ghosh ◽  
Tapas Kumar Maji
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Catalytic Activity ◽  
Metal Ions ◽  
Lewis Acid ◽  
Heavy Metal Ions ◽  
Toxic Metal ◽  
Acid Catalyst ◽  
Toxic Metal Ions ◽  
Lewis Acid Catalyst

An anionic MOF shows the potential to capture toxic metal ions from water and the CuII@AMOF hybrid obtained through post-synthetic metalation is used as a Lewis acid catalyst.

scholarly journals Highly efficient Lewis acid catalytic art of tritylium ion at the node of tensile organic framework

2021 ◽  
Author(s):  
Shuai Zhao ◽  
Juhui Zhang ◽  
Yongchang Zhai ◽  
Xiaoqin Zou ◽  
Shaolei Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Acid Catalyst ◽  
Highly Efficient ◽  
Long Time ◽  
Lewis Acid Catalyst ◽  
Organic Framework

Tritylium salts have been used as Lewis acid catalyst in organic synthesis for a long time. In this work, we found that the Lewis acid catalytic activity of tritylium ions...

scholarly journals Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

2013 ◽  
Vol 9 ◽  
pp. 1698-1704 ◽  
Author(s):  
Rajesh Munirathinam ◽  
Roberto Ricciardi ◽  
Richard J M Egberink ◽  
Jurriaan Huskens ◽  
Michael Holtkamp ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Photoelectron Spectroscopy ◽  
Polymer Brushes ◽  
Silicon Oxide ◽  
Polymer Brush ◽  
Acid Catalyst ◽  
Ring Closure ◽  
Oxide Surface ◽  
Lewis Acid Catalyst

Polystyrene sulfonate polymer brushes, grown on the interior of the microchannels in a microreactor, have been used for the anchoring of gallium as a Lewis acid catalyst. Initially, gallium-containing polymer brushes were grown on a flat silicon oxide surface and were characterized by FTIR, ellipsometry, and X-ray photoelectron spectroscopy (XPS). XPS revealed the presence of one gallium per 2–3 styrene sulfonate groups of the polymer brushes. The catalytic activity of the Lewis acid-functionalized brushes in a microreactor was demonstrated for the dehydration of oximes, using cinnamaldehyde oxime as a model substrate, and for the formation of oxazoles by ring closure of ortho-hydroxy oximes. The catalytic activity of the microreactor could be maintained by periodic reactivation by treatment with GaCl3.

Enhanced catalytic activity of a hierarchical porous metal–organic framework CuBTC

CrystEngComm ◽  
2015 ◽  
Vol 17 (37) ◽  
pp. 7124-7129 ◽  
Author(s):  
Zhigang Hu ◽  
Yongwu Peng ◽  
Kai Min Tan ◽  
Dan Zhao
Keyword(s):  
Catalytic Activity ◽  
Pore Size ◽  
Lewis Acid ◽  
Metal Organic Framework ◽  
Porous Metal ◽  
Acid Catalyst ◽  
Hierarchical Porous ◽  
Metal Organic ◽  
Lewis Acid Catalyst ◽  
Organic Framework

A hierarchical porous metal–organic framework CuBTC with mesopores of 3.9 nm pore size has been facilely obtained as Lewis acid catalyst.

Thioacetalization of aldehydes and ketones in the presence of hydroxo complexes of platinum(II): An example of Lewis acid catalytic activity

2001 ◽  
Vol 79 (5-6) ◽  
pp. 621-625 ◽  
Author(s):  
Lorenzo Battaglia ◽  
Francesco Pinna ◽  
Giorgio Strukul
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Reaction Rate ◽  
Platinum Complex ◽  
Acid Catalyst ◽  
High Catalytic Activity ◽  
Hydroxo Complexes ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst

The complex [(dppb)Pt(µ-OH)]2(BF4)2 displays high catalytic activity in the thioacetalization of a variety of aldehydes and ketones with mercaptoethanol under very mild conditions. The reaction rate is greatly enhanced by the addition to the reaction mixture of magnesium perchlorate as drying agent and molar turnovers as high as 9700 can be observed. The effect of different desiccating agents is also reported. The reactivity pattern observed, the similarity with other reactions and NMR spectroscopic investigations confirm the possible role of the complex as Lewis acid catalyst in promoting the reaction.Key words: thioacetalization, catalysis, aldehydes, ketones, platinum complex.

Mesoporous Zr-Beta zeolites prepared by a post-synthetic strategy as a robust Lewis acid catalyst for the ring-opening aminolysis of epoxides

2015 ◽  
Vol 17 (3) ◽  
pp. 1744-1755 ◽  
Author(s):  
Bo Tang ◽  
Weili Dai ◽  
Xiaoming Sun ◽  
Guangjun Wu ◽  
Naijia Guan ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Catalytic Activity ◽  
Lewis Acid ◽  
Ring Opening ◽  
Acid Catalyst ◽  
Amino Alcohols ◽  
Synthetic Strategy ◽  
Beta Zeolites ◽  
Lewis Acid Catalyst ◽  
Catalytic Deactivation

Mesoporous Zr-Beta exhibits a remarkable catalytic activity and regio-selectivity to β-amino alcohols in epoxide aminolysis. Intra-crystalline mesopores greatly promote the reaction through enhanced mass transfer and suppress the catalytic deactivation.

Computationally-Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

2020 ◽  
Author(s):  
Eric Greve ◽  
Jacob D. Porter ◽  
Chris Dockendorff
Keyword(s):  
Lewis Acid ◽  
Density Functional ◽  
Acid Catalyst ◽  
Metal Catalyst ◽  
Catalyst Poisoning ◽  
Lewis Acid Catalysts ◽  
Metal Ligands ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst ◽  
Catalyst Systems

Dual amine/pi Lewis acid catalyst systems have been reported for intramolecular direct additions of aldehydes/ketones to unactivated alkynes and occasionally alkenes, but related intermolecular reactions are rare and not presently of significant synthetic utility, likely due to undesired coordination of enamine intermediates to the metal catalyst. We reasoned that bulky metal ligands and bulky amine catalysts could minimize catalyst poisoning and could facilitate certain examples of direct intermolecular additions of aldehyde/ketones to alkenes/alkynes. Density Functional Theory (DFT) calculations were performed that suggested that PyBOX-Pt(II) catalysts for alkene/alkyne activation could be combined with MacMillan’s imidazolidinone organocatalyst for aldehyde/ketone activation to facilitate desirable C-C bond formations, and certain reactions were calculated to be more exergonic than catalyst poisoning pathways. As calculated, preformed enamines generated from the MacMillan imidazolidinone did not displace ethylene from a biscationic (<i>t</i>-Bu)PyBOX-Pt<sup>2+</sup>complex, but neither were the desired C-C bond formations observed under several different conditions.

Computationally-Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

2020 ◽  
Author(s):  
Eric Greve ◽  
Jacob D. Porter ◽  
Chris Dockendorff
Keyword(s):  
Lewis Acid ◽  
Density Functional ◽  
Acid Catalyst ◽  
Metal Catalyst ◽  
Catalyst Poisoning ◽  
Lewis Acid Catalysts ◽  
Metal Ligands ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst ◽  
Catalyst Systems

Dual amine/pi Lewis acid catalyst systems have been reported for intramolecular direct additions of aldehydes/ketones to unactivated alkynes and occasionally alkenes, but related intermolecular reactions are rare and not presently of significant synthetic utility, likely due to undesired coordination of enamine intermediates to the metal catalyst. We reasoned that bulky metal ligands and bulky amine catalysts could minimize catalyst poisoning and could facilitate certain examples of direct intermolecular additions of aldehyde/ketones to alkenes/alkynes. Density Functional Theory (DFT) calculations were performed that suggested that PyBOX-Pt(II) catalysts for alkene/alkyne activation could be combined with MacMillan’s imidazolidinone organocatalyst for aldehyde/ketone activation to facilitate desirable C-C bond formations, and certain reactions were calculated to be more exergonic than catalyst poisoning pathways. As calculated, preformed enamines generated from the MacMillan imidazolidinone did not displace ethylene from a biscationic (<i>t</i>-Bu)PyBOX-Pt<sup>2+</sup>complex, but neither were the desired C-C bond formations observed under several different conditions.

Bis(pentafluorophenyl)tin Dibromide as a Novel Organotin Halide Lewis Acid Catalyst

Synlett ◽  
1996 ◽  
Vol 1996 (09) ◽  
pp. 877-879 ◽  
Author(s):  
Jianxie Chen ◽  
Katsumasa Sakamoto ◽  
Akihiro Orita ◽  
Junzo Otera
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Lewis Acid Catalyst

Asymmetric synthesis of isoquinuclidines by Diels–Alder reaction of 1,2-dihydropyridine utilizing a chiral Lewis acid catalyst

Tetrahedron ◽  
2012 ◽  
Vol 68 (6) ◽  
pp. 1774-1781 ◽  
Author(s):  
Chigusa Seki ◽  
Masafumi Hirama ◽  
N.D.M. Romauli Hutabarat ◽  
Junko Takada ◽  
Chonticha Suttibut ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Acid Catalyst ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Chiral Lewis Acid ◽  
Lewis Acid Catalyst
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