Highly efficient Ir-catalyzed asymmetric hydrogenation of benzoxazinones and derivatives with a Brønsted acid cocatalyst
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چکیده
منابع مشابه
Chiral phosphine-phosphoramidite ligands for highly efficient Ir-catalyzed asymmetric hydrogenation of sterically hindered N-arylimines.
A mild and general iridium-catalyzed, highly enantioselective hydrogenation of sterically hindered N-arylimines with a new H(8)-BINOL-derived phosphine-phosphoramidite ligand has been developed. The present catalytic system features high turnover numbers (up to 100000) and good to perfect enantioselectivities (up to 99% ee) for the hydrogenation of a variety of sterically hindered N-arylimines.
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The first highly efficient Ir-catalyzed enantioselective hydrogenation of β-acylamino nitroolefins is reported. This reaction provides straightforward access to chiral β-amino nitroalkanes in high yields and excellent enantioselectivities (up to >99.9% ee) catalyzed by an Ir-(R,R)-f-spiroPhos complex.
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Enantiomerically pure â-amino acids and their derivatives are important building blocks for the synthesis of â-peptides, â-lactam antibiotics, and many important drugs (e.g., taxol side chain).1 Peptides containing â-amino acids show increased stability to enzymatic hydrolysis and are being evaluated as promising pharmaceutical products. Recent studies show that a variety of â-peptides can fold...
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A direct asymmetric hydrogenation of unprotected enamino esters and amides is described. Catalyzed by Rh complexes with Josiphos-type chiral ligands, this method gives beta-amino esters and amides in high yield and high ee (93-97% ee). No acyl protection/deprotection is required.
متن کاملHighly efficient synthesis of chiral beta-amino acid derivatives via asymmetric hydrogenation.
The Rh-TangPhos complex is an efficient hydrogenation catalyst for making chiral beta-amino acid derivatives. With the Rh-TangPhos system, high enantioselectivities (up to 99.6%) and turnover numbers have been obtained in the hydrogenation of E/Z isomeric mixtures of both beta-alkyl and beta-aryl beta-(acylamino)acrylates. [reaction: see text]
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ژورنال
عنوان ژورنال: Chemical Science
سال: 2019
ISSN: 2041-6520,2041-6539
DOI: 10.1039/c8sc05797d