Infrared Spectra of RhCO+, RhCO, and RhCO-in Solid Neon:  A Scale for Charge in Supported Rh(CO) Catalyst Systems

1999 ◽  
Vol 121 (39) ◽  
pp. 9171-9175 ◽  
Author(s):  
Mingfei Zhou ◽  
Lester Andrews
Keyword(s):  
Infrared Spectra ◽  
Co Catalyst ◽  
Catalyst Systems

scholarly journals Biomimetic Cu/Nitroxyl Catalyst Systems for Selective Alcohol Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 395 ◽  
Author(s):  
Lindie Marais ◽  
Andrew John Swarts
Keyword(s):  
Active Sites ◽  
Alcohol Oxidation ◽  
Galactose Oxidase ◽  
Co Catalyst ◽  
Co Catalysts ◽  
Mechanistic Pathway ◽  
Oxidation Of Alcohols ◽  
Catalyst Systems ◽  
Carbonyl Products

The oxidation of alcohols to the corresponding carbonyl products is an important organic transformation and the products are used in a variety of applications. The development of catalytic methods for selective alcohol oxidation have garnered significant attention in an attempt to find a more sustainable method without any limitations. Copper, in combination with 2,2,6,6-tetramethyl-1-piperidine N-oxyl (TEMPO) and supported by organic ligands, have emerged as the most effective catalysts for selective alcohol oxidation and these catalyst systems are frequently compared to galactose oxidase (GOase). The efficiency of GOase has led to extensive research to mimic the active sites of these enzymes, leading to a variety of Cu/TEMPO· catalyst systems being reported over the years. The mechanistic pathway by which Cu/TEMPO· catalyst systems operate has been investigated by several research groups, which led to partially contradicting mechanistic description. Due to the disadvantages and limitations of employing TEMPO· as co-catalyst, alternative nitroxyl radicals or in situ formed radicals, as co-catalysts, have been successfully evaluated in alcohol oxidation. Herein we discuss the development and mechanistic elucidation of Cu/TEMPO· catalyst systems as biomimetic alcohol oxidation catalysts.

Cross-metathesis of some functionalized olefins with cyclo- and bicycloolefins catalyzed by WCl6— silicon-containing co-catalyst systems

1994 ◽  
Vol 90 (1-2) ◽  
pp. 21-27 ◽  
Author(s):  
N.B. Bespalova ◽  
M.A. Bovina ◽  
M.B. Sergeeva ◽  
V.D. Oppengeim ◽  
V.G. Zaikin
Keyword(s):  
Co Catalyst ◽  
Cross Metathesis ◽  
Catalyst Systems

Synergistic visible light photoredox catalysis

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
Kirsten Zeitler ◽  
Matthias Neumann
Keyword(s):  
Transition Metal ◽  
Open Shell ◽  
Base Catalysis ◽  
Photoredox Catalysis ◽  
Metal Catalysis ◽  
Co Catalyst ◽  
Acid And Base ◽  
Catalyst Systems ◽  
Lewis Acid And Base ◽  
Catalytic Cycles

Abstract Within the last decade the combination of photoredox catalysis and other catalytic modes of activation has become a powerful tool for organic synthesis to enable transformations that are not possible using single catalyst systems and hence are complementary to traditional methodology. Especially reactions proceeding via synergistic catalysis where co-catalyst and photocatalyst simultaneously and separately activate different reaction partners greatly benefit from the special properties of molecules and transition metal complexes in their excited state being oxidizing and reducing in nature at the same time. Apart from allowing for the generation of radical (open-shell) reactive intermediates by SET under mild conditions from bench-stable, abundant precursors, the photocatalyst often acts to interweave the distinct catalytic cycles by interaction at multiple points of the reaction mechanism to provide overall redox-neutral processes by shuttling electrons within in this complex network of elementary reaction steps. Synergistic strategies moreover may allow to performing such reactions with enantioselectivity, while mostly the selectivity is achieved by the chiral co-catalyst. The merger of photocatalysis has been achieved with a broad range of alternative modes of catalysis including organocatalysis, Brønstedt and Lewis acid and base catalysis, enzyme catalysis as well as in the context of cross-coupling transition metal catalysis overcoming challenging steps in this methodology and therefore has contributed to considerably expand the repertoire of suitable coupling partners. While only selected examples will be discussed, this chapter will highlight various dual catalytic platforms focusing on the photocatalytically generated intermediates, but also illustrating the diverse roles of photocatalysts in the context of such synergistic multicatalysis reactions.

scholarly journals Boronic acid/Brønsted acid co-catalyst systems for the synthesis of 2H-chromenes from phenols and α,β-unsaturated carbonyls

2016 ◽  
Vol 14 (28) ◽  
pp. 6703-6711 ◽  
Author(s):  
Victoria Dimakos ◽  
Tishaan Singh ◽  
Mark S. Taylor
Keyword(s):  
Catalytic Activity ◽  
Boronic Acid ◽  
Boronic Acids ◽  
Bronsted Acids ◽  
Bronsted Acid ◽  
Efficient Synthesis ◽  
Co Catalyst ◽  
Brönsted Acid ◽  
Unsaturated Carbonyls ◽  
Catalyst Systems

Combinations of boronic acids and Brønsted acids showing optimal co-catalytic activity for condensations of enals or enones with phenols have been identified, enabling an efficient synthesis of 2H-chromenes.

The infrared spectra of some diamines and diamine salts

1962 ◽  
Vol 18 (4) ◽  
pp. 1455-1461 ◽  
Author(s):  
M BALDWIN
Keyword(s):  
Infrared Spectra

Infrared spectra of carbon monoxide on platinum, iridium and copper ; comparison of flat and rough surfaces

1981 ◽  
Vol 78 ◽  
pp. 927-932 ◽  
Author(s):  
F.J.C.M. Toolenaar ◽  
G.J. van der Poort ◽  
F. Stoop ◽  
V. Ponec
Keyword(s):  
Carbon Monoxide ◽  
Infrared Spectra ◽  
Rough Surfaces

MODELING THE CONFORMATION-SPECIFIC INFRARED SPECTRA OF N-ALKYLBENZENES

2016 ◽  
Author(s):  
Daniel Tabor ◽  
Timothy Zwier ◽  
Joseph Korn ◽  
Daniel Hewett ◽  
Edwin Sibert
Keyword(s):  
Infrared Spectra
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