The Role of Support Hydrophobicity in the Selective Hydrogenation of Enones and Unsaturated Sulfones over Cu/SiO2 Catalysts

The substitution of complex hydrides and Ni- and noble metal-based catalysts in the synthesis of pharma and fragrance products is a relevant topic in the green chemistry scenario. Here, we report that non-toxic, non-noble metal-based Cu/SiO2 catalysts are effective and very selective in the hydrogenation of α,β-unsaturated ketones, esters and sulfones under very mild conditions. Vanillyl acetone can be obtained in quantitative yield in 1 h at 90 °C and 1 bar of H2. High dispersion of the metallic phase and support wettability play a significant role in determining catalytic performance.

Download Full-text

Robust and efficient hydrogenation of carbonyl compounds catalysed by mixed donor Mn(I) pincer complexes

Nature Communications ◽

10.1038/s41467-020-20168-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Wenjun Yang ◽

Ivan Yu. Chernyshov ◽

Robin K. A. van Schendel ◽

Manuela Weber ◽

Christian Müller ◽

...

Keyword(s):

Noble Metal ◽

Crucial Role ◽

Carbonyl Compounds ◽

Catalytic Performance ◽

Hydrogen Atmosphere ◽

Pincer Complexes ◽

Catalyst Activation ◽

Hydrogenation Catalysts ◽

Induction Times

AbstractAny catalyst should be efficient and stable to be implemented in practice. This requirement is particularly valid for manganese hydrogenation catalysts. While representing a more sustainable alternative to conventional noble metal-based systems, manganese hydrogenation catalysts are prone to degrade under catalytic conditions once operation temperatures are high. Herein, we report a highly efficient Mn(I)-CNP pre-catalyst which gives rise to the excellent productivity (TOF° up to 41 000 h−1) and stability (TON up to 200 000) in hydrogenation catalysis. This system enables near-quantitative hydrogenation of ketones, imines, aldehydes and formate esters at the catalyst loadings as low as 5–200 p.p.m. Our analysis points to the crucial role of the catalyst activation step for the catalytic performance and stability of the system. While conventional activation employing alkoxide bases can ultimately provide catalytically competent species under hydrogen atmosphere, activation of Mn(I) pre-catalyst with hydride donor promoters, e.g. KHBEt3, dramatically improves catalytic performance of the system and eliminates induction times associated with slow catalyst activation.

Download Full-text

Highly reduced molybdophosphate as a noble-metal-free catalyst for the reduction of chromium using formic acid as a reducing agent

Journal of Materials Chemistry A ◽

10.1039/c4ta06830k ◽

2015 ◽

Vol 3 (11) ◽

pp. 6019-6027 ◽

Cited By ~ 43

Author(s):

Kaining Gong ◽

Weijie Wang ◽

Jinshuang Yan ◽

Zhangang Han

Keyword(s):

Formic Acid ◽

Noble Metal ◽

Catalytic Performance ◽

Reducing Agent ◽

Metal Free ◽

Mild Conditions

Cobalt-containing polyoxometalates exhibit catalytic performance for toxic chromium(vi) reduction using formic acid under mild conditions.

Download Full-text

Pyridine-decorated carbon nanotubes as a metal-free heterogeneous catalyst for mild CO2 reduction to methanol with hydroboranes

Catalysis Science & Technology ◽

10.1039/c7cy01772c ◽

2017 ◽

Vol 7 (24) ◽

pp. 5833-5837 ◽

Cited By ~ 11

Author(s):

G. Tuci ◽

A. Rossin ◽

L. Luconi ◽

C. Pham-Huu ◽

S. Cicchi ◽

...

Keyword(s):

Carbon Nanotubes ◽

Heterogeneous Catalyst ◽

Co2 Reduction ◽

Catalytic Performance ◽

Metal Free ◽

Mild Conditions ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Pyridine decorated multi-walled carbon nanotubes have been employed as heterogeneous metal-free catalysts for CO2 hydroboration to methyl borinate under mild conditions. Mechanistic insights have unveiled the non-innocent role of the nanotube carrier in the catalytic performance.

Download Full-text

A seed-mediated approach to the general and mild synthesis of non-noble metal nanoparticles stabilized by a metal–organic framework for highly efficient catalysis

Materials Horizons ◽

10.1039/c5mh00125k ◽

2015 ◽

Vol 2 (6) ◽

pp. 606-612 ◽

Cited By ~ 33

Author(s):

Yu-Zhen Chen ◽

Linfeng Liang ◽

Qihao Yang ◽

Maochun Hong ◽

Qiang Xu ◽

...

Keyword(s):

Metal Nanoparticles ◽

Noble Metal ◽

Noble Metals ◽

Metal Organic Framework ◽

Catalytic Performance ◽

Noble Metal Nanoparticles ◽

Mild Conditions ◽

Highly Efficient ◽

Metal Organic ◽

Seed Mediated

A novel noble metal-seed-mediated approach to reduce non-noble metals under mild conditions to afford non-noble metal NPs with superior catalytic performance.

Download Full-text

Effect of the ortho-hydroxy group of salicylaldehyde in the A3 coupling reaction: A metal-catalyst-free synthesis of propargylamine

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.13.53 ◽

2017 ◽

Vol 13 ◽

pp. 552-557 ◽

Cited By ~ 9

Author(s):

Sujit Ghosh ◽

Kinkar Biswas ◽

Suchandra Bhattacharya ◽

Pranab Ghosh ◽

Basudeb Basu

Keyword(s):

Green Chemistry ◽

Hydroxy Group ◽

Building Block ◽

Coupling Reaction ◽

Metal Catalyst ◽

Terminal Alkyne ◽

Mild Conditions ◽

Metal Catalyzed ◽

A3 Coupling

The synthesis of propargylamines via A3 coupling mostly under metal-catalyzed procedures is well known. This work invented an unprecedented effect of salicylaldehyde, one of the A3 coupling partners, which could lead to the formation of propargylamine, an important pharmaceutical building block, in the absence of any metal catalyst and under mild conditions. The role of the hydroxy group in ortho position of salicylaldehyde has been explored, which presumably activates the Csp–H bond of the terminal alkyne leading to the formation of propargylamines in good to excellent yields, thus negating the function of the metal catalyst. This observation is hitherto unknown, tested for a variety of salicylaldehyde, amine and acetylene, established as a general protocol, and is believed to be of interest for synthetic chemists from green chemistry.

Download Full-text

Selective methanation of CO over supported noble metal catalysts: Effects of the nature of the metallic phase on catalytic performance

Applied Catalysis A General ◽

10.1016/j.apcata.2008.03.039 ◽

2008 ◽

Vol 344 (1-2) ◽

pp. 45-54 ◽

Cited By ~ 190

Author(s):

Paraskevi Panagiotopoulou ◽

Dimitris I. Kondarides ◽

Xenophon E. Verykios

Keyword(s):

Noble Metal ◽

Catalytic Performance ◽

Metallic Phase ◽

Metal Catalysts ◽

Noble Metal Catalysts

Download Full-text

Positive Role of Synthesis Method and Hard Template on the Catalytic Performance of SAPO-34 in Methanol to Olefin Reaction.

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323666200720103321 ◽

2020 ◽

Vol 23 ◽

Author(s):

Sajjad Rimaz ◽

Reza Katal

Keyword(s):

Particle Size ◽

Synthesis Method ◽

Catalytic Performance ◽

Hard Template ◽

Structure Directing Agent ◽

Positive Role ◽

Methanol To Olefin ◽

Dg Method ◽

Synthesis Procedure

: In the present study, SAPO-34 particles were synthesized using hydrothermal (HT) and dry gel (DG) conversion methods in the presence of diethyl amine (DEA) as an organic structure directing agent (SDA). Carbon nanotubes (CNT) were used as hard template in the synthesis procedure to introduce transport pores into the structures of the synthesized samples. The synthesized samples were characterized with different methods to reveal effects of synthesis method and using hard template on their structure and catalytic performance in methanol to olefin reaction (MTO). DG conversion method results in smaller particle size in comparison with hydrothermal method, resulting in enhancing catalytic performance. On the other side, using CNT in the synthesis procedure with DG method results in more reduction in particle size and formation of hierarchical structure which drastically improves catalytic performance.

Download Full-text

Role of Zeolites and Zeotypes in Green Chemistry

Current Green Chemistry ◽

10.2174/2213346107999201208214310 ◽

2020 ◽

Vol 07 ◽

Author(s):

Jyotsna S. Meshram ◽

Devendra S. Raghuvanshi

Keyword(s):

Green Chemistry ◽

Industrial Process ◽

Environmental Issues ◽

Synthetic Methods ◽

Acid Catalysts ◽

Chemical Waste ◽

Specific Morphology

Abstract:: Now days, it is of utmost important to design synthetic methods; which can be utilized for the generation of substances that will minimize toxicity to health of human and the environment. The utilization of acid catalysts generates lots of corrosive and harmful wastes which has to be treated with appropriate alkalis. Hence, it generates lots of sludge and alarms environmental issues of its storage and disposal. Zeolites and Zeotypes; by virtue of their peculiar properties; such as specific morphology, porosity and residing acidity; attracting enormous attention as they replaces harmful acid catalysts efficiently and also reduces chemical waste in industrial process; Hence emerged as new plethora in the field of “Green Chemistry”.

Download Full-text