(+)‐Cinchonine‐Decorated Dendrimers as Recoverable Organocatalysts

Abstract

The hydrodeoxygenation (HDO) of maize oil was performed in an autoclave with Mo‐based catalysts supported by different carbon materials, such as reduced graphene oxide, activated charcoal, graphite, and fullerene. Nanostructured Mo‐based catalysts with different phase compositions were prepared by using the carbothermal hydrogen reduction method at temperatures ranging from 500 to 700 °C and characterized by Raman spectroscopy, N2 adsorption isotherms, SEM, TEM, XRD, X‐ray photoelectron spectroscopy, and ammonia temperature‐programmed desorption. The highest total hydrocarbon yield of 90.32 % was obtained on the reduced graphene oxide‐supported molybdenum carbide catalyst at 700 °C. These results are subject to the complicated effect of different factors such as phase composition, defect concentration, and particle size on the catalytic behavior of the materials. Unique structures of different supports also play a significant role in the HDO reaction. On the basis of the results of comprehensive analysis of products and catalysts, an HDO mechanism was proposed. These Mo‐based catalysts are a promising system to prepare high‐quality diesel fuels from renewable resources.

Homogeneous catalysis with phosphorus dendrimer complexes

“…Two examples with phosphorhydrazone dendrimers has shown the pertinence of this approach (Fig. 19 [73,75]), and recovery and reuse over 10 cycles was also demonstrated without loss of activity or enantioselectivity. Most of the work concerning catalysis with dendrimers demonstrates that the outcome of the catalytic reactions is generation dependant, but not linearly, and the "best" generation is not always the same.…”

“…Generation 1 was found the most efficient catalyst. Its recovery and reuse over 10 cycles was demonstrated without loss of activity or enantioselectivity [73].…”

Synthetic Methodologies for Chelating Polymer Ligands: Recent Advances and Future Development

“…However, selective modification of the dendrimer surface for various functions is very difficult . As a typical example, we note a surface modification of phosphorus‐containing dendrimers to obtain (+)‐cinchonine fragments . The interaction between phenol, formaldehyde and G0 or G1 PAMAM dendrimers results in the production of two dendrimers containing pendant benzoxazine groups .…”

Phosphorhydrazones as Useful Building Blocks for Special Architectures: Macrocycles and Dendrimers

“…Many functionalized phenols have been prepared from tyramine;, this includes functions having biological properties such as azabisphosphonic acid salts, of different types, diverse amino phosphonates, azabis carboxylate and azabis sulfonate salts, several mannose derivatives, ethacrynic acid, diverse phosphines such as an azabisphosphine, a thiazolylphosphine, and an iminophosphine, diverse fluorophores such as a maleimide, and a derivative of rhodamine . Other functionalized phenols comprise ligands for catalysis, such as phosphine, and diphosphine, iminophosphine, aminophosphine, diketone, pyridineimine, terpyridine, bisoxazoline, prolinol derivative, and cinchonine, diverse other compounds, such as aminophosphoniums, thioesters and thioamides, two types of ethacrynic derivatives,, long chains of type alkyl or perfluoroalkyl, or PEG (polyethyleneglycol), and fluorescent groups based on stilbazole or fluorene derivatives , . Miscellaneous functions are nitrile and dimethylamino, or alkyne and azide, or d ‐xylose, or ammonium (Figure ).…”