Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 

Saved Queries

Sign in to use this feature.

Search Filter Reset All

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
Add Subjects Reset
Select Subjects

Journals

remove_circle_outline
Add Journals Reset
Select Journals

Article Types

remove_circle_outline
Add Article Types Reset
Select Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
Add Countries / Regions Reset
Select Countries / Regions
Update Search
share announcement

Search Results (2)

Search Parameters:
Keywords = heterogeneous enantioselective hydrogenation

Order results
Result details
Results per page
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
17 pages, 2271 KB  
Article
Hydrogenation of α,β-Unsaturated Carbonyl Compounds over Covalently Heterogenized Ru(II) Diphosphine Complexes on AlPO4-Sepiolite Supports
by Verónica Caballero, Rafael Estevez, Diego Luna, Felipa M. Bautista, Antonio A. Romero, Laura Aguado-Deblas, Jesús Hidalgo-Carrillo and Isabel Romero
Catalysts 2021, 11(2), 289; https://doi.org/10.3390/catal11020289 - 22 Feb 2021
Cited by 1 | Viewed by 3609
Abstract
In this work, the covalent immobilization of two ruthenium(II) complexes, i.e., [RuIICl (bpea){(S)(-)(BINAP)}](BF4), 1, and [RuIICl(bpea)(DPPE)](BF4), 2, where BINAP = 2,2’-bis(diphenylphosphino)-1,1’-binaphthyl and DPPE = 1,2-bis(diphenylphosphino)ethane, have been obtained (AlPO4-Sepiolite@1 and AlPO [...] Read more.
In this work, the covalent immobilization of two ruthenium(II) complexes, i.e., [RuIICl (bpea){(S)(-)(BINAP)}](BF4), 1, and [RuIICl(bpea)(DPPE)](BF4), 2, where BINAP = 2,2’-bis(diphenylphosphino)-1,1’-binaphthyl and DPPE = 1,2-bis(diphenylphosphino)ethane, have been obtained (AlPO4-Sepiolite@1 and AlPO4-Sepiolite@2) by using a N-tridentate ligand N,N-bis-(2-pyridylmethyl)ethylamine (bpea), linked to an amorphous AlPO4-Sepiolite (20/80) inorganic support. This AlPO4-sepiolite support is able to immobilize the double amount of ruthenium complex (1.65%) than the amorphous AlPO4 (0.89%). Both heterogenized complexes have been assessed as catalysts in the liquid phase hydrogenation of several substrates with carbonyl and/or olefinic double bonds using methanol as solvent, attaining good catalytic activity and high enantioselectivity (99%). The highest Turn Over Number (TON) value (748.6) was obtained over the [RuII Cl (bpea)(DPPE)](BF4) 2 catalyst, although the [RuIICl(bpea){(S)(-)(BINAP)}](BF4) 1 exhibits better reusability. In fact, the [RuIICl(bpea){(S)(-)(BINAP)}](BF4) immobilized on AlPO4-Sepiolite maintained the activity throughout 14 successive runs. Furthermore, some findings on hydrogenation mechanisms of the α,β-unsaturated carbonyl compounds over Ru catalysts have been also obtained. Full article
(This article belongs to the Special Issue Recent Advances in Organometallic Chemistry and Catalysis)
►▼ Show Figures

Figure 1

12 pages, 4642 KB  
Article
Facile Synthesis of P25@Pd Core-Shell Catalyst with Ultrathin Pd Shell and Improved Catalytic Performance in Heterogeneous Enantioselective Hydrogenation of Acetophenone
by Xiuyun Gao, Lulu He, Juntong Xu, Xueying Chen and Heyong He
Catalysts 2019, 9(6), 513; https://doi.org/10.3390/catal9060513 - 9 Jun 2019
Cited by 5 | Viewed by 3881
Abstract
Heterogeneous enantioselective hydrogenation is an ideal method for synthesizing important chiral compounds in pesticides and pharmaceuticals. Up to the present, supported noble-metal catalysts are most widely studied in heterogeneous enantioselective hydrogenations. However, it is found that the weak interactions existing on the surface [...] Read more.
Heterogeneous enantioselective hydrogenation is an ideal method for synthesizing important chiral compounds in pesticides and pharmaceuticals. Up to the present, supported noble-metal catalysts are most widely studied in heterogeneous enantioselective hydrogenations. However, it is found that the weak interactions existing on the surface of support may have negative effects on the enantioselectivity. Herein, a new category of TiO2 (Aeroxide® P25) supported Pd catalyst with ultrathin Pd shell was successfully prepared via a simple strategy based on the reduction of PdI carbonyl complex. Characterization results show that a well-dispersed ultrathin Pd shell with an average thickness of ~1.0 nm and a Pd loading of 36 wt.% was formed over the surface of P25 support. By excluding the negative weak interactions from the support, the P25@Pd core-shell catalyst with unique electronic properties of Pd exhibits higher activity and enantioselectivity than that of Pd/P25 catalyst prepared by the impregnation method and unsupported Pd black catalyst in the enantioselective hydrogenation of acetophenone. Full article
(This article belongs to the Special Issue Catalysis by Precious Metals, Past and Future)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying article 1-50 on page 1 of 1.
Back to TopTop