373 research outputs found
Ruthenium Complexes as Efficient Catalysts for Transfer Hydrogenation Reactions
No full textRuthenium Complexes as Efficient Catalysts for Transfer Hydrogenation Reactions
W. Baratta
Dipartimento DI4A, Università di Udine, Via Cotonificio 108, 33100 Udine, Italy
e-mail: [email protected]
The employment of selective and productive ruthenium catalysts for transfer hydrogenation (TH) and hydrogenation of carbonyl compounds is a cost-effective and environmentally benign way for the production of alcohols. Since TH is a reversible reaction, these catalysts can be used for the Oppenauer-type oxidation of alcohols and related C-H activation reactions, namely alcohol racemization and borrowing hydrogen reactions.
In order to improve the catalytic activity and retard decomposition, the design of suitable metal systems based on chelating and non-innocent ligands appears crucial.
The preparation of ruthenium complexes and their use as efficient catalysts for TH of ketones and aldehydes, including biomass-derived molecules (5-HMF, ethyl levulinate), Oppenauer-type alcohol oxidation, amine alkylation with alcohols and photochemical TH of carbonyl compounds are presented
Cyclometallated Ruthenium Complexes for Transfer Hydrogenation and Hydrogenation Reactions
No full textCyclometallated Ruthenium Complexes for Transfer Hydrogenation and Hydrogenation Reactions Walter Baratta,a,* Salvatore Baldino,a Maurizio Ballico,a Rosario Figliolia,a Steven Giboulot,a,b Ennio Zangrando,c Shuanming Zhanga a Department DI4A, University of Udine, Via Cotonificio 108, 33100 Udine, Italy b Johnson Matthey, 28 Cambridge Science Park, Milton Road, Cambridge, CB4 0FP, United Kingdom c Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri, 1, 34127 Trieste, Italy e-mail: [email protected] The catalytic hydrogenation and transfer hydrogenation of carbonyl compounds to alcohols is a reaction of broad application in the industry, resulting in a lower environmental impact and an easier work-up with respect to the classical approach with NaBH4, LiAlH4 and Al alkoxides.1 The search of well-designed and productive catalysts of ruthenium, which is cheaper with respect to rhodium and iridium, has led to a number of efficient hydrogenation systems. We report here the isolation of highly active ruthenium cyclometallated CNN and PC catalysts containing the ampy motif2 with phosphine and CO ligands, starting from phosphine and carbonyl Ru precursors. The presence of a metal-carbon σ-bond leads to robust and productive catalysts for the reduction of commercial-grade aldehydes and (bulky) ketones using H2 (5-30 atm), 2-propanol or ammonium formate,3 with S/C up to 100000 and TOF up to 100000 h-1. Acknowledgements We gratefully acknowledge the financial support from MIUR (PRIN 2015, n° 20154X9ATP_005) References 1. (a) Xie, X.; Lu, B.; Li, W.; Zhang, Z. Coord. Chem. Rev. 2018, 355, 39. (b) Wang, D.; Astruc, D. Chem. Rev. 2015, 115, 6621. 2 Chelucci, G.; Baldino, S.; Baratta, W. Coord. Chem. Rev. 2015, 300, 29. 3 Baldino, S.; Facchetti, S.; Nedden, H. G.; Zanotti-Gerosa, A.; Baratta, W. ChemCatChem, 2016, 8, 3195
Novelty in Transfer Hydrogenation and Related Reactions Catalyzed by Ruthenium Catalysts
No full textTransfer hydrogenation (TH) is a straightforward transformation for the reduction of carbonyl compounds to alcohols using suitable hydrogen donors under mild reaction conditions. Conversely, carbonyl compounds can be obtained by alcohols by means of hydrogen acceptors without the use of hazardous oxidants. As a result of the reversibility of the TH, borrowing hydrogen transformations, namely C-C and C-N forming reactions, can be achieved via C-H activation. In order to have access to selective catalytic processes, the development of well-defined homogenous catalysts, obtained through a fine tuning of non-innocent ligands via metal-ligand cooperativity, is a current research target.1 In addition, high catalyst productivity is a critical factor for applications and relies on the design of robust catalysts.
This presentation deals with the preparation of ruthenium complexes, containing bidentate and pincer ligands, which display high activity in the TH of carbonyl compounds, Oppenauer-type alcohol oxidation, alcohol racemization, hydrogenation, dehydrogenation, amine alkylation and photochemical TH reactions (Figure 1). Mechanistic studies indicates that Ru-hydrides and Ru-alkoxides are key species involved in the catalytic processes
1-(Pyridin-2-yl)methanamine-Based Ruthenium Catalysts for Fast Transfer Hydrogenation of Carbonyl Compounds in 2-Propanol
No full text
Sintesi di alcoli da chetoni: una nuova classe di catalizzatori a base di Ru(II). Chimica & Industria, 88 (2006)44
No full textMicroreview “1-(Pyridin-2-yl)methanamine-Based Ruthenium Catalysts for Fast Transfer Hydrogenation of Carbonyl Compounds in 2-Propanol”
No full textUn mensaje de Alessandro Baratta.
No full textLo que sigue es una reflexión relacionada con el libro de nuestro autor, titulado: Positivismo Jurídico y Ciencia del Derecho Penal. Aspectos teóricos e ideológicos del desarrollo de la Ciencia Penal alemana desde el inicio del Siglo hasta 1933, publicado por Giuffrè de Milán en el año 1966. Libro cuyo tema ha sido escogido para analizarlo en el Seminario sobre el Pensamiento de Alessandro Baratta, a celebrar en el año 2016, y que contiene un mensaje muy claro para los penalistas latinoamericanos de hoy.Lo que sigue es una reflexión relacionada con el libro de nuestro autor, titulado: Positivismo Jurídico y Ciencia del Derecho Penal. Aspectos teóricos e ideológicos del desarrollo de la Ciencia Penal alemana desde el inicio del Siglo hasta 1933, publicado por Giuffrè de Milán en el año 1966. Libro cuyo tema ha sido escogido para analizarlo en el Seminario sobre el Pensamiento de Alessandro Baratta, a celebrar en el año 2016, y que contiene un mensaje muy claro para los penalistas latinoamericanos de hoy.Lo que sigue es una reflexión relacionada con el libro de nuestro autor, titulado: Positivismo Jurídico y Ciencia del Derecho Penal. Aspectos teóricos e ideológicos del desarrollo de la Ciencia Penal alemana desde el inicio del Siglo hasta 1933, publicado por Giuffrè de Milán en el año 1966. Libro cuyo tema ha sido escogido para analizarlo en el Seminario sobre el Pensamiento de Alessandro Baratta, a celebrar en el año 2016, y que contiene un mensaje muy claro para los penalistas latinoamericanos de hoy
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