Author, as appears in the article.: Biosca M; Magre M; Coll M; Pàmies O; Diéguez M
Department: Química Física i Inorgànica Química Física i Inorgànica
URV's Author/s: Biosca Brull, Maria / COLL SERRAHIMA, MARIA MERCÈ / Diéguez Fernández, Montserrat / Pamies Ollé, Oscar
Keywords: Unfunctionalized olefins Rhodium Iridium Hydrogenation Cyclic β-enamides Cyclic ?-enamides
Abstract: © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim This study presents a new series of readily accessible iridium- and rhodium-phosphite/oxazoline catalytic systems that can efficiently hydrogenate, for the first time, both minimally functionalized olefins and functionalized olefins (62 examples in total) in high enantioselectivities (ees up to >99%) and conversions. The phosphite-oxazoline ligands, which are readily available in only two synthetic steps, are derived from previous privileged 4-alkyl-2-[2-(diphenylphosphino)phenyl]-2-oxazoline (PHOX) ligands by replacing the phosphine moiety by a biaryl phosphite group and/or the introduction of a methylene spacer between the oxazoline and the phenyl ring. The modular design of the ligands has given us the opportunity not only to overcome the limitations of the iridium-PHOX catalytic systems in the hydrogenation of minimally functionalized Z-olefins and 1,1-disubstituted olefins, but also to expand their use to unfunctionalized olefins containing other challenging scaffolds (e.g., exocyclic benzofused and triaryl-substituted olefins) and also to olefins with poorly coordinative groups (e.g., α,β-unsaturated lactams, lactones, alkenylboronic esters, etc.) with enantioselectivities typically >95% ee. Moreover, both enantiomers of the hydrogenation product could be obtained by simply changing the configuration of the biaryl phosphite moiety. Remarkably, the new catalytic systems also provided excellent enantioselectivities (up to 99% ee) in the asymmetric hydrogenation of another challenging class of olefins – the functionalized cyclic β-enamides. Again, both enantiomers of the reduced amides could be obtained by changing the metal from Ir to Rh. We also demonstrated that environmentally friendly propylene carbonate can be used with no loss of enantioselectivity. Another advantage of the new ligands over the PHOX ligands is that the best ligands are derived from the affordable (S)-phenylglycinol rather than from the expensive (S)-tert-leucinol. (Figure presented.).
Thematic Areas: Química Organic chemistry Materiais Engenharias iv Engenharias ii Ciências biológicas ii Ciência de alimentos Chemistry, organic Chemistry, applied Catalysis Biodiversidade Astronomia / física
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 1615-4150
Author's mail: maria.biosca@urv.cat oscar.pamies@urv.cat montserrat.dieguez@urv.cat
Author identifier: 0000-0002-9116-6318 0000-0002-2352-8508 0000-0002-8450-0656
Last page: 2814
Record's date: 2024-09-07
Journal volume: 359
Papper version: info:eu-repo/semantics/acceptedVersion
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: Advanced Synthesis & Catalysis. 359 (16): 2801-2814
APA: Biosca M; Magre M; Coll M; Pàmies O; Diéguez M (2017). Alternatives to Phosphinooxazoline (t-BuPHOX) Ligands in the Metal-Catalyzed Hydrogenation of Minimally Functionalized Olefins and Cyclic β-Enamides. Advanced Synthesis & Catalysis, 359(16), 2801-2814. DOI: 10.1002/adsc.201700573
Entity: Universitat Rovira i Virgili
Journal publication year: 2017
First page: 2801
Publication Type: Journal Publications
Repositori URV