- A theoretically-guided optimization of a new family of modular P,S-ligands for iridium-catalyzed hydrogenation of minimally functionalized olefins
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A library of modular iridium complexes derived from thioether-phosphite/phosphinite ligands has been evaluated in the asymmetric iridium-catalyzed hydrogenation of minimally functionalized olefins. The modular ligand design has been shown to be crucial in finding highly selective catalysts for each substrate. A DFT study of the transition state responsible for the enantiocontrol in the Ir-catalyzed hydrogenation is also described and used for further optimization of the crucial stereodefining moieties. Excellent enantioselectivities (enantiomeric excess (ee) values up to 99%) have been obtained for a range of substrates, including E- and Z-trisubstituted and disubstituted olefins, α,β-unsaturated enones, tri- and disubstituted alkenylboronic esters, and olefins with trifluoromethyl substituents.
- Margalef, Jèssica,Caldentey, Xisco,Karlsson, Erik A.,Coll, Mercè,Mazuela, Javier,Pàmies, Oscar,Diéguez, Montserrat,Pericàs, Miquel A.
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p. 12201 - 12214
(2015/03/31)
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- Aqueous asymmetric transfer hydrogenation using modular hydrophobic aminoalcohols
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A series of new modular Ru/aminoalcohol systems were used as enantioselective catalysts in the asymmetric transfer hydrogenation reaction in both water and 2-propanol. The catalytic behavior exhibited in these two media follows different tendencies regard
- Alza, Esther,Bastero, Amaia,Jansat, Susanna,Pericas, Miquel A.
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p. 374 - 378
(2008/09/19)
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- Kinetic Resolution of Epoxides by a C-C Bond-Forming Reaction: Highly Enantioselective Addition of Indoles to cis, trans, and meso Aromatic Epoxides Catalyzed by [Cr(salen)] Complexes
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The high reactivity of indoles has led to a new approach for the kinetic resolution of epoxides. [Cr(salen)] efficiently catalyzes a new C-C bond-forming reaction that allows the kinetic resolution of cis and trans aromatic epoxides (see scheme). By employing the same catalytic system, different indolyl derivatives were obtained in high enantiomeric excesses (up to 98%) by asymmetric ring opening of meso-stilbene oxide.
- Bandini, Marco,Cozzi, Pier Giorgio,Melchiorre, Paolo,Umani-Ronchi, Achille
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- Asymmetric aminolysis of aromatic epoxides: A facile catalytic enantioselective synthesis of anti-β-amino alcohols
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The first asymmetric aminolysis of trans-aromatic epoxides with anilines is described. The process affords enantioenriched anti-β-amino alcohols in up to 99% ee. The complete regio- and diastereoselectivity observed uses commercially available [Cr(Salen)CI] as a Lewis acid catalyst and in combination with a very simple experimental procedure renders the present reaction a facile and practical tool for the synthesis of chiral nonracemic anti-β-amino alcohols.
- Bartoli, Giuseppe,Bosco, Marcella,Carlone, Armando,Locatelli, Manuela,Massaccesi, Massimo,Melchiorre, Paolo,Sambri, Letizia
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p. 2173 - 2176
(2007/10/03)
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