15 research outputs found
Efficient and Practical Transfer Hydrogenation of Ketones Catalyzed by a Simple Bidentate MnâNHC Complex
Catalytic reductions of carbonylâcontaining compounds are highly important for the safe, sustainable, and economical production of alcohols. Herein, we report on the efficient transfer hydrogenation of ketones catalyzed by a highly potent Mn(I)âNHC complex. MnâNHC 1 is practical at metal concentrations as low as 75â
ppm, thus approaching loadings more conventionally reserved for noble metal based systems. With these low Mn concentrations, catalyst deactivation is found to be highly temperature dependent and becomes especially prominent at increased reaction temperature. Ultimately, understanding of deactivation pathways could help close the activity/stabilityâgap with Ru and Ir catalysts towards the practical implementation of sustainable earthâabundant Mnâcomplexes
Supported nickel-rhenium catalysts for selective hydrogenation of methyl esters to alcohols
The addition of Re to Ni on TiO2 yields efficient catalysts for the hydrogenation of acids and esters to alcohols under mild conditions. Rhenium promotes the formation of atomically dispersed and sub-nanometre-sized bimetallic species interacting strongly with the oxide support
Fuelling the hydrogen economy:scale-up of an integrated formic acid-to-power system
\u3cp\u3eTransitioning from fossil fuels to sustainable and green energy sources in mobile applications is a difficult challenge and demands sustained and highly multidisciplinary efforts in R&D. Liquid organic hydrogen carriers (LOHC) offer several advantages over more conventional energy storage solutions, but have not been yet demonstrated at scale. Herein we describe the development of an integrated and compact 25 kW formic acid-to-power system by a team of BSc and MSc students. We highlight a number of key engineering challenges encountered during scale-up of the technology and discuss several aspects commonly overlooked by academic researchers. Conclusively, we provide a critical outlook and suggest a number of developmental areas currently inhibiting further implementation of the technology.\u3c/p\u3
Catalytic (de)hydrogenation promoted by non-precious metals-Co, Fe and Mn:recent advances in an emerging field
\u3cp\u3eCatalytic hydrogenation and dehydrogenation reactions form the core of the modern chemical industry. This vast class of reactions is found in any part of chemical synthesis starting from the milligram-scale exploratory organic chemistry to the multi-ton base chemicals production. Noble metal catalysis has long been the key driving force in enabling these transformations with carbonyl substrates and their nitrogen-containing counterparts. This review is aimed at introducing the reader to the remarkable progress made in the last three years in the development of base metal catalysts for hydrogenations and dehydrogenative transformations.\u3c/p\u3
Manganese-Mediated CâC Bond Formation: Alkoxycarbonylation of Organoboranes
Alkoxycarbonylations are important and versatile reactions that result in the formation of a new C-C bond. Herein, we report on a new and halide-free alkoxycarbonylation reaction that does not require the application of an external carbon monoxide atmosphere. Instead, manganese carbonyl complexes and organo(alkoxy)borate salts react to form an ester product containing the target C-C bond. The required organo(alkoxy)borate salts are conveniently generated from the stoichiometric reaction of an organoborane and an alkoxide salt and can be telescoped without purification. The protocol leads to the formation of both aromatic and aliphatic esters and gives complete control over the ester's substitution (e.g., OMe, OtBu, OPh). A reaction mechanism was proposed on the basis of stoichiometric reactivity studies, spectroscopy, and DFT calculations. The new chemistry is particularly relevant for the field of Mn(I) catalysis and clearly points to a potential pathway toward irreversible catalyst deactivation
Raw data for paper "Manganese-mediated C-C bond formation: alkoxycarbonylation of organoboranes"
The dataset contains all spectral data produced and used in the preparation of the above mentioned manuscript.Numbering follows that of the available ESI that is published with the manuscript. For each entry the figurenumber is stated, together with a short description (usually the figure caption). The corresponding spectraldata is provided as xy-coordinates in the units indicated in the figure.</div
Raw data for paper "Manganese-mediated C-C bond formation: alkoxycarbonylation of organoboranes"
The dataset contains all spectral data produced and used in the preparation of the above mentioned manuscript.Numbering follows that of the available ESI that is published with the manuscript. For each entry the figurenumber is stated, together with a short description (usually the figure caption). The corresponding spectraldata is provided as xy-coordinates in the units indicated in the figure.</div
Manganese-Mediated CâC Bond Formation: Alkoxycarbonylation of Organoboranes
Alkoxycarbonylations are important and versatile reactions that result in the formation of a new C-C bond. Herein, we report on a new and halide-free alkoxycarbonylation reaction that does not require the application of an external carbon monoxide atmosphere. Instead, manganese carbonyl complexes and organo(alkoxy)borate salts react to form an ester product containing the target C-C bond. The required organo(alkoxy)borate salts are conveniently generated from the stoichiometric reaction of an organoborane and an alkoxide salt and can be telescoped without purification. The protocol leads to the formation of both aromatic and aliphatic esters and gives complete control over the ester's substitution (e.g., OMe, OtBu, OPh). A reaction mechanism was proposed on the basis of stoichiometric reactivity studies, spectroscopy, and DFT calculations. The new chemistry is particularly relevant for the field of Mn(I) catalysis and clearly points to a potential pathway toward irreversible catalyst deactivation