Rhodium-Catalyzed Enantioselective Hydrogenation Research Articles

NDIPhos as a platform for chiral supramolecular ligands in rhodium-catalyzed enantioselective hydrogenation.

Chiral naphthalene diimide ligands (NDIPhos) were exploited in rhodium-catalyzed enantioselective hydrogenation. The key feature of these ligands is their ability to self-assemble via π-π interactions to mimic bidentate ligands, offering a complementary method to traditional supramolecular strategies. This concept was further substantiated by computations with the composite electronic-structure method r2SCAN-3c.

Enantioselective Rhodium-Catalyzed Hydrogenation of (Z)-N-Sulfonyl-α-dehydroamido Boronic Esters.

Highly enantioselective rhodium-catalyzed hydrogenation of (Z)-N-sulfonyl-α-dehydroamido boronic esters is realized for the first time using a JosiPhos-type ligand. This method has enabled convenient synthesis of a series of enantio-enriched N-sulfonyl-α-amido boronic esters in good yields and excellent enantioselectivities (up to 99% ee).

Total Synthesis of Conulothiazole A.

An efficient total synthesis of the chlorinated thiazole-containing natural product conulothiazole A is reported. Key features of this synthesis include a novel rhodium-catalyzed enantioselective hydrogenation of a 2-enamido-thiazole and a vinylic Finkelstein reaction that could be implemented at all stages of the synthesis to install the chlorinated alkene.

Enantioselective Rhodium-Catalyzed Hydro-genation of Tri- and Tetrasubstituted Olefins

Enantioselective Rhodium-Catalyzed Hydro-genation of Tri- and Tetrasubstituted Olefins

Rhodium-catalyzed enantioselective hydrogenation of α-amino acrylonitriles: an efficient approach to synthesizing chiral α-amino nitriles.

An efficient rhodium-catalyzed asymmetric hydrogenation of α-amino acrylonitriles has been developed, affording α-acylamino nitriles with high yields and excellent enantioselectivities (up to 99% yield and >99% ee). This novel methodology provides an efficient and concise synthetic route to chiral α-amino nitriles, which are versatile intermediates in organic synthesis.

Rhodium-Catalyzed Enantioselective Hydrogenation of Enamido Esters

Rhodium-Catalyzed Enantioselective Hydrogenation of Enamido Esters

Rhodium-catalyzed enantioselective hydrogenation of tetrasubstituted α-acetoxy β-enamido esters: a new approach to chiral α-hydroxyl-β-amino acid derivatives.

Asymmetric hydrogenation of tetrasubtitued α-acetoxy β-enamido esters with rhodium catalysts based on chiral diphosphine ligands provides an efficient and concise route to the synthesis of chiral α-hydroxyl-β-amino acid derivatives in excellent enantioselectivities. The products are valuable chiral building blocks in many biologically active compounds and have important applications in organic synthesis.

Rhodium-Catalyzed Enantioselective Hydrogenation of 1-Alkylvinyl Benzoates

Rhodium-Catalyzed Enantioselective Hydrogenation of 1-Alkylvinyl Benzoates

Rhodium-Catalyzed Enantioselective Hydrogenation of β-Acylamino Nitroolefins: A New Approach to Chiral β-Amino Nitroalkanes

An efficient and highly enantioselective catalytic asymmetric hydrogenation of β-acylamino nitroolefins has been realized by using Rh-TangPhos as the catalyst. A series of β-amino nitroalkane products, which are versatile intermediates in organic synthesis, were obtained with high yield and good enantioselectivity.

ChemInform Abstract: Rhodium‐Catalyzed Enantioselective Hydrogenation of Oxime Acetates.

Rh-catalyzed enantioselective hydrogenation of oxime acetates was first reported, which afforded a new approach for chiral amine synthesis.

Rhodium-Catalyzed Enantioselective Hydrogenation of Oxime Acetates

Rhodium-Catalyzed Enantioselective Hydrogenation of Oxime Acetates

Rhodium-Catalyzed Enantioselective Hydrogenation of Oxime Acetates

Rh-catalyzed enantioselective hydrogenation of oxime acetates was first reported, which afforded a new approach for chiral amine synthesis.

Rhodium-catalyzed asymmetric olefin hydrogenation by easily accessible aniline- and pyridine-derived chiral phosphites

An aniline- and two pyridine-derived (R)-BINOL-based P,N-containing phosphite ligands have been synthesized via a one-pot procedure. Treatment of the aniline-derived ligand with 1equiv of [Rh(COD)2]BF4 yielded a mixture of a P,N-chelate complex and a biligated P-monodentate complex (exclusively obtained by treatment of the ligand with rhodium in a ratio of 2:1), while the pyridine analogues led to the corresponding P,N-bidentate complexes as unique species. For the first time, such phosphites were studied for rhodium-catalyzed enantioselective olefin hydrogenation. At room temperature, the aniline-derived ligand was found to be more active and selective compared to the pyridine analogues, which can probably be attributed to its different coordination mode and the formation of a biligated P-monodentate complex.

Synthesis of novel chiral monophosphine ligands derived from isomannide and isosorbide. Application to enantioselective hydrogenation of olefins

A new class of monophosphine ligands has been prepared from natural chirality renewable source, 1,4:3,6-dianhydrohexitol compounds, via a nucleophilic substitution process, or a hydrophosphination reaction involving microwave activation. These ligands have been evaluated for the rhodium-catalyzed enantioselective hydrogenation of olefins giving good conversion and enantioselectivity up to 95% and 96% ee, respectively.

Enantioselective hydrogenation of (Z)- and (E)-β-arylenamides catalyzed by rhodium complexes of monodentate chiral spiro phosphorous ligands: a new access to chiral β-arylisopropylamines

A highly enantioselective rhodium-catalyzed hydrogenation of both (Z)- and (E)-β-arylenamides was developed by using monodentate chiral spiro phosphite and phosphine ligands, respectively. The hydrogenation reaction provides an efficient access to optically active β-arylisopropylamines, important building blocks for the synthesis of biologically active compounds.

Rhodium-Catalyzed Enantioselective Hydrogenation of Unsaturated Phosphonates by ClickFerrophos Ligands

Newly developed ClickFerrophos II ligands were applied in the hydrogenation of α,β-unsaturated phosphonates. The use of a rhodium/ClickFerrophos II catalyst was examined in the hydrogenation of functionalized α,β-unsaturated phosphonates and was revealed to be effective for β-alkyl-β-aryl or β-dialkyl phosphonates, (Z)-β-enolester phosphonates, and α-phenylethenyl phosphonates, producing the corresponding chiral phosphonates in good yields with high enantioselectivities (up to 96% ee).

Rhodium‐Catalyzed Asymmetric Hydrogenation of Olefins with PhthalaPhos, a New Class of Chiral Supramolecular Ligands

A library of 19 binol-derived chiral monophosphites that contain a phthalic acid diamide group (PhthalaPhos) has been designed and synthesized in four steps. These new ligands were screened in the rhodium-catalyzed enantioselective hydrogenation of prochiral dehydroamino esters and enamides. Several members of the library showed excellent enantioselectivity with methyl 2-acetamido acrylate (6 ligands gave >97% ee), methyl (Z)-2-acetamido cinnamate (6 ligands gave >94% ee), and N-(1-phenylvinyl)acetamide (9 ligands gave >95% ee), whilst only a few representatives afforded high enantioselectivities for challenging and industrially relevant substrates N-(3,4-dihydronaphthalen-1-yl)-acetamide (96% ee in one case) and methyl (E)-2-(acetamidomethyl)-3-phenylacrylate (99% ee in one case). In most cases, the new ligands were more active and more stereoselective than their structurally related monodentate phosphites (which are devoid of functional groups that are capable of hydrogen-bonding interactions). Control experiments and kinetic studies were carried out that allowed us to demonstrate that hydrogen-bonding interactions involving the diamide group of the PhthalaPhos ligands strongly contribute to their outstanding catalytic properties. Computational studies carried out on a rhodium precatalyst and on a conceivable intermediate in the hydrogenation catalytic cycle shed some light on the role played by hydrogen bonding, which is likely to act in a substrate-orientation effect.

Phenol-derived chiral phosphine–phosphite ligands in the rhodium-catalyzed enantioselective hydrogenation of functionalized olefins

A set of 15 chiral Taddol- and Binol-based phosphine–phosphite ligands were tested in the Rh-catalyzed asymmetric hydrogenation of three olefins, methyl 2-hydroxymethyl-acrylate, 1-phenylvinyl acetate, and α-methyl cinnamic acid. The best enantioselectivities (up to 92% ee) were observed in the hydrogenation of methyl 2-hydroxymethyl-acrylate using Binol-based ligands. As previously observed in other applications of this class of modular chiral ligand in enantioselective catalysis, the stereochemical outcome of the reactions greatly depended on the substituents at the ligand aryl backbone in the ortho-position to the chiral phosphite unit.

ChemInform Abstract: New Diphosphinite Ligands Derived from Mannitol for Rhodium-Catalyzed Enantioselective Hydrogenation of Ketones.

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Enantioselective Rh-catalyzed hydrogenation of N-acyl dehydroamino esters and enamides with monodentate phosphoramidite ligands

Chiral monodentate phosphoramidite ligands were conveniently prepared from 1,1′-bi-2-naphthol (BINOL) and (S)-pyrrolidine in good yields, which were effective chiral ligands in the enantioselective rhodium-catalyzed hydrogenation of dehydroamino esters and enamides at low hydrogenation pressure. High conversion rate (up to 99% for dehydroamino esters and enamides) and good enantioselectivity (up to 96.3% ee for dehydroamino esters and 91.7% ee for enamides) were obtained.