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16 May 17:23

Practical Synthesis of Amides via Copper/ABNO-Catalyzed Aerobic Oxidative Coupling of Alcohols and Amines

by Susan L. Zultanski, Jingyi Zhao and Shannon S. Stahl

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Journal of the American Chemical Society
DOI: 10.1021/jacs.6b03931
26 Feb 00:00

[Report] Palladium-tin catalysts for the direct synthesis of H2O2 with high selectivity

by Simon J. Freakley
The direct synthesis of hydrogen peroxide (H2O2) from H2 and O2 represents a potentially atom-efficient alternative to the current industrial indirect process. We show that the addition of tin to palladium catalysts coupled with an appropriate heat treatment cycle switches off the sequential hydrogenation and decomposition reactions, enabling selectivities of >95% toward H2O2. This effect arises from a tin oxide surface layer that encapsulates small Pd-rich particles while leaving larger Pd-Sn alloy particles exposed. We show that this effect is a general feature for oxide-supported Pd catalysts containing an appropriate second metal oxide component, and we set out the design principles for producing high-selectivity Pd-based catalysts for direct H2O2 production that do not contain gold. Authors: Simon J. Freakley, Qian He, Jonathan H. Harrhy, Li Lu, David A. Crole, David J. Morgan, Edwin N. Ntainjua, Jennifer K. Edwards, Albert F. Carley, Albina Y. Borisevich, Christopher J. Kiely, Graham J. Hutchings
16 Apr 16:20

A Further Decrease in the Catalyst Loading for the Palladium-Catalyzed Direct Intramolecular Arylation of Amides and Sulfonamides

by Nerea Conde, Fátima Churruca, Raul SanMartin, María Teresa Herrero, Esther Domínguez


The direct arylation of N-substituted o-bromobenzanilides and benzenesulfonamides via C[BOND]H bond functionalization has been developed using very low catalyst loadings. This novel cost-effective and more sustainable method relies on a PCN-type palladium pincer complex as a highly active palladium source, providing a general and efficient access to phenanthridinones, biaryl sultams and related heterocyclic systems. The beneficial effect of water as cosolvent has been observed in this process, which is not seriously influenced by electronic effects at the arene moieties or sterically demanding substituents at the amide or sulfonamide nitrogen. In addition, a number of experiments (kinetic plot, poisoning assays, TEM, ESI) have been performed in order to understand the role of the employed palladium complex in this reaction.

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21 Jan 18:34

Rhodium-Catalyzed C–H Activation of Phenacyl Ammonium Salts Assisted by an Oxidizing C–N Bond: A Combination of Experimental and Theoretical Studies

by Songjie Yu, Song Liu, Yu Lan, Boshun Wan and Xingwei Li

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Journal of the American Chemical Society
DOI: 10.1021/ja511796h
22 Dec 11:30

Coating Polycyclic Aromatic Hydrocarbon Cations with Helium Clusters: Snowballs and Slush

by Florent Calvo

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The Journal of Physical Chemistry A
DOI: 10.1021/jp510799h
15 Dec 00:00

Spatial control of functional properties via octahedral modulations in complex oxide superlattices

by E. J. Moon


Structural properties have been a key factor that controls the electronic and magnetic behaviour at the interface of two oxide materials. Here the authors achieve a spatial control over these functional properties in oxides through the formation of octahedral superstructures in manganite superlattices.

Nature Communications doi: 10.1038/ncomms6710

Authors: E. J. Moon, R. Colby, Q. Wang, E. Karapetrova, C. M. Schlepütz, M. R. Fitzsimmons, S. J. May

03 Nov 20:30

Hierarchically Organized Silica–Titania Monoliths Prepared under Purely Aqueous Conditions

by Sylvia Flaig, Johanna Akbarzadeh, Paolo Dolcet, Silvia Gross, Herwig Peterlik, Nicola Hüsing


Hierarchically organized silica–titania monoliths were synthesized under purely aqueous conditions by applying a new ethylene glycol-modified single-source precursor, such as 3-[3-{tris(2-hydroxyethoxy)silyl}propyl]acetylacetone coordinated to a titanium center. The influence of the silicon- and titanium-containing single-source precursor, the novel glycolated organofunctional silane, and the addition of tetrakis(2-hydroxyethyl)orthosilicate on the formation of the final porous network was investigated by SEM, TEM, nitrogen sorption, and SAXS/WAXS. In situ SAXS measurements were performed to obtain insight into the development of the mesoporous network during sol–gel transition. IR-ATR, UV/Vis, XPS, and XAFS measurements showed that up to a Si/Ti ratio of 35:1, well-dispersed titanium centers in a macro-/mesoporous SiO2 network with a specific surface area of up to 582 m2 g−1 were obtained. An increase in Ti content resulted in a decrease in specific surface area and a loss of the cellular character of the macroporous network. With a 1:1 Si/Ti ratio, silica–titania powders with circa 100 m2 g−1 and anatase domains within the SiO2 matrix were obtained.

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Hierarchically organized SiO2/TiO2 monoliths were synthesized in purely aqueous conditions by applying an ethylene glycol modified single-source precursor (SSP), such as 3-[3-{tris(2-hydroxyethoxy)silyl}propyl]acetylacetonate coordinated to a titanium center. The influence of the SSP on the formation of the final porous network was investigated. The homogeneity of the Si and Ti centers in the oxide matrix was also investigated.

05 Jul 16:10

Reversible carbon-carbon bond formation between carbonyl compounds and a ruthenium pincer complex

Chem. Commun., 2013, 49,7147-7149
DOI: 10.1039/C3CC43517B, Communication
Chelsea A. Huff, Jeff W. Kampf, Melanie S. Sanford
This communication describes the reversible reaction of a ruthenium pincer complex with a variety of carbonyl compounds.
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25 Apr 18:28

[Report] Direct Evidence of a Dinuclear Copper Intermediate in Cu(I)-Catalyzed Azide-Alkyne Cycloadditions

by B. T. Worrell
The mechanism of a common and highly versatile molecular coupling reaction is elucidated.

Authors: B. T. Worrell, J. A. Malik, V. V. Fokin
18 Apr 18:26

The Cinchona Primary Amine-Catalyzed Asymmetric Epoxidation and Hydroperoxidation of α,β-Unsaturated Carbonyl Compounds with Hydrogen Peroxide

by Olga Lifchits, Manuel Mahlau, Corinna M. Reisinger, Anna Lee, Christophe Farès, Iakov Polyak, Gopinadhanpillai Gopakumar, Walter Thiel and Benjamin List

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Journal of the American Chemical Society DOI: 10.1021/ja402058v