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Due to the linear coordination nature of gold(I) catalysts, achieving high enantiocontrol in asymmetric gold catalysis is a great challenge. To improve the enantiocontrol of gold catalysis, an ion‐pairing strategy was therefore proposed. A series of bifunctional P,N ligands based on chiral spirocyclic and biaryl scaffolds were synthesized and applied in the gold(I)‐catalyzed desymmetric lactonization of alkynylmalonic acids. A wide range of chiral lactones containing an α‐position quaternary stereocenter were synthesized with high yields, excellent regioselectivity and enantioselectivity under mild reaction conditions. The synthetic utilities of the current reaction were demonstrated by gram‐scale synthesis and transformations of chiral lactones. The origin of enantioselectivity and the role of the alcohol additive were elucidated via control experiments and DFT calculations. [ABSTRACT FROM AUTHOR]

Chiral carboxylic acids are important compounds because of their prevalence in pharmaceuticals, natural products and agrochemicals. Asymmetric hydrogenation of α,β‐unsaturated carboxylic acids has been widely recognized as one of the most efficient synthetic approaches to afford such compounds. Although related asymmetric hydrogenation of di‐ and trisubstituted unsaturated acids with noble metals is well established, asymmetric hydrogenation of challenging tetrasubstituted α,β‐unsaturated carboxylic acids is rarely reported. We demonstrate enantioselective hydrogenation of cyclic and acyclic tetrasubstituted α,β‐unsaturated carboxylic acids via cobalt(II) catalysis. This protocol showed broad substrate scope and gave chiral carboxylic acids in good yields with excellent enantiocontrol (up to 98 % yield and 99 % ee). Combined experimental and computational mechanistic studies support a CoII catalytic cycle involving migratory insertion and σ‐bond metathesis processes. DFT calculations reveal that enantioselectivity may originate from the steric effect between the phenyl groups of the ligand and the substrate. [ABSTRACT FROM AUTHOR]

α-Chiral primary amines are one among the most valuable and versatile building blocks for the synthesis of numerous amine-containing pharmaceuticals and natural compounds. They also serve as chiral ligands or organo-catalysts for asymmetric catalysis. However, most of the existing chemocatalytic methods toward enantiopure primary amines rely on multistep manipulations on N-substituted substrates, which are not ideally atom-economical and cost-effective. Among the catalytic methods including the asymmetric transformations of the pre-prepared or in situ formed NH imines, biomimetic chemocatalysis inspired by enzymatic transaminations has recently emerged as an appealing and straightforward method to access chiral primary amines. This tutorial review highlights the state-of-the-art catalytic methods for the direct asymmetric synthesis of α-chiral primary amines and demonstrates their utility in the construction of molecular complexities, which may attract extensive attention and inspire applications in synthetic and medicinal chemistry. [ABSTRACT FROM AUTHOR]

A highly efficient ruthenium‐catalyzed asymmetric reductive amination (ARA) of racemic β‐keto lactams with molecular hydrogen and ammonium salts is disclosed for the synthesis of enantiomerically pure primary amino lactams through dynamic kinetic resolution (DKR). By this approach, a range of syn primary β‐amino lactams were obtained in high yields with high chemo‐, enantio‐, and diastereoselectivity (up to 98 % yield, 99 % ee, >20:1 d.r. syn products). The utility of the products has been demonstrated by rapid access to a key synthetic intermediate towards biologically active drug molecules. Meanwhile, mechanistic studies and control experiments indicate that the reaction may proceed through the hydrogenation of an iminium intermediate. Resolved, problem solved: Racemic β‐keto lactams underwent ruthenium‐catalyzed asymmetric reductive amination with molecular hydrogen and ammonium salts to give enantiomerically enriched primary amino lactams in high yields with high chemo‐ and stereoselectivity through dynamic kinetic resolution. Mechanistic studies suggest that the reaction pathway may involve the hydrogenation of iminium ions rather than enamine intermediates. [ABSTRACT FROM AUTHOR]

Go catalytic! A highly enantioselective hydrogenation of β,β‐disubstituted nitroalkenes and isomeric mixtures of nitroalkenes by using a Rh/DuanPhos catalytic system under basic conditions has furnished a convenient approach to β‐chiral nitroalkanes, which are otherwise not so easy to make (see scheme). [ABSTRACT FROM AUTHOR]

A new type of chiral bisoxazoline ligands 1 based on spiro[4,4]-1,6-nonadiene backbone was easily prepared in six steps from racemic spiro[4,4]-nonane-1,6-dione, with the Pd-catalyzed coupling of the enol triflates with CO and amino alcohols as the key steps for the construction of the oxazoline moiety. The structure of the ligand (R,S,S)-1b was unambiguously established by X-ray crystallographic analysis. The chiral Cu(II) complex generated in situ from the combination of spiro bisoxazoline ligand (S,S,S)-1c and Cu(OTf)2 was effective in the catalysis of asymmetric chlorination of the β-ketoester, methyl 1-oxo-2,3-dihydro-1H- indene-2-carboxylate, affording the corresponding chlorinated derivative in 99% yield with 17% ee. [ABSTRACT FROM AUTHOR]

(S,R)-Indan–ambox ligand and its ruthenium(ii) complex have been prepared and successfully applied to asymmetric hydrogenation of prochiral simple ketones. A wide range of unfunctionalized ketones are reduced by Ru(ii)-indan–ambox catalyst with excellent enantioselectivities (up to 97% ee). [ABSTRACT FROM AUTHOR]

High enantioselectivities are observed in the Rh-catalyzed asymmetric hydrogenation of α-ketone enol acetates using DuanPhos as the ligand. [ABSTRACT FROM AUTHOR]

Abstract: A series of new diphosphite ligands have been easily prepared from BINOL derivatives; moderate enantioselectivities (up to 80% ee) and excellent regioselectivities (b/l up to 98/2) have been achieved in the Rh-catalyzed asymmetric hydroformylation of vinyl acetate. [Copyright &y& Elsevier]

Abstract: A new class of conformationally rigid phosphino-oxazoline ligands 3 were synthesized via an efficient ortho-substitution of phenyl glycinol as the key step. Divergent synthetic routes for easy ligand modulation, as well as a procedure suitable for scale-up synthesis, were established. The catalytic potential of ligands 3 has been demonstrated in the highly enantioselective Ir-catalyzed hydrogenation of alkenes and Pd-catalyzed allylic substitution and intermolecular Heck reactions. [Copyright &y& Elsevier]

The first rhodium-catalyzed, highly chemo- and enantioselective hydrogenation of a variety of α,β-disubstituted nitroalkenes (I) and (III) is reported. The nitroalkane products, e.g. (II) and (IV), provide entry to valuable chiral amphetamine derivatives. [ABSTRACT FROM AUTHOR]

Review: [52 refs. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Synthesis of 4-Aryl-2,3-dihydropyrroles via Rh-Catalyzed Intramolecular Hydroamino-Methylation Reaction" by X. Zhang and others, published in "Tetrahedron Letters" in 2014.

Chemical formulas showing a synthesis of chiral cyclicßamino ketones by Ru-catalyzed asymmetric hydrogenation are presented.

This method yields the hydrogenation products with excellent enantioselectivities. [ABSTRACT FROM AUTHOR]

The article presents chemical equations for the article "New Ruthenium Complexes Based on Tetradentate Bipyridine Ligands for Catalytic Hydrogenation of Esters" by F. Wang and colleagues published in "Chemistry - An Asian Journal" in 2016.

The article presents chemical equations for an article "Tunable P-Chiral Bisdihydrobenzooxaphosphole Ligands for Enantioselective Hydroformylation" by R. Tan and others, which appeared in 2016 issue of journal "Organic Letters."

The reaction tolerates diaryl as well as dialkyl substituted alkynes. [ABSTRACT FROM AUTHOR]

For the first time, a strategy for the enantioselective Rh-TaniaPhos catalyzed asymmetric hydrogenation of unprotected β-enamine phosphonates directly to free β-amino phosphonates is reported which occurs with high yields and good enantioselectivities (up to 86% ee). [ABSTRACT FROM AUTHOR]

The activation of the N-heteroaromatic substrates with HCl introduces anion binding into the catalytic system and is crucial for this reaction. [ABSTRACT FROM AUTHOR]

The highly efficient and direct asymmetric reductive amination of arylacetones catalyzed by an iridium complex for the preparation of enantiomerically pure β-arylamines is described. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Highly Enantioselective Hydrogenation of Oxy Functionalized α β Unsaturated Acids Catalyzed by a ChenPhos-Rh Complex in CF3CH2OH" by L. Yao and others, published in journal "Chemical Communications" in 2016.

Cyclic enamido esters undergo asymmetric hydrogenation in the presence of the optically active rhodium catalyst (RCT) to form 2-oxazolidinones in excellent yields with good enantioselectivities. [ABSTRACT FROM AUTHOR]

The products are obtained in very high yields and with high (alkyl) or excellent (aryl and hetaryl substituted derivatives) enantiomeric excesses. [ABSTRACT FROM AUTHOR]

A graphical abstract of the article "Rhodium Catalyzed Asymmetric Hydrogenation of 2-Pyridine Ketones" is presented.

The article presents chemical reactions for highly enantioselective synthesis of non-natural aliphatic α-amino acids via asymmetric hydrogenation.

The article presents chemical reactions for first iridium-catalyzed highly enantioselective hydrogenation of β-nitroacrylates.

Review: [31 refs. [ABSTRACT FROM AUTHOR]

An efficient enantioselective synthesis of β-amino alcohols is achieved by rhodium-catalyzed asymmetric hydrogenation of enamides. [ABSTRACT FROM AUTHOR]

A diagram for highly efficient synthesis of chiral α-CF3 amines through rhodium (Rh)-catalyzed asymmetric hydrogenation is presented.

The methodology provides valuable building blocks for the synthesis of biologically active compounds which is exemplified by the transformation of one product into the corresponding α-hydroxy-β-amino acid, an intermediate of the taxol side chain. [ABSTRACT FROM AUTHOR]

Chiral piperidines are easily prepared by Ir-catalyzed asymmetric hydrogenation of alkylpyridinium salts. [ABSTRACT FROM AUTHOR]

The hydrogenation provides chiral amines in high yields and enantioselectivities up to 95% ee. [ABSTRACT FROM AUTHOR]

Mild conditions, broad substrate scope, and the commercially available Rh-DuanPhos catalyst are features of this hydrogenation. [ABSTRACT FROM AUTHOR]

A library of easily tunable, sterically bulky ligands is synthesized among which the one shown causes the highest conversions and enantiomeric excesses for the products as well as the best ratio of branched to linear products. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Direct Catalytic Asymmetric Reductive Amination of Simple Aromatic Ketones" by M. Chang, S. Liu, K. Huang and others, published in the periodical "Organic Letters" in 2013.

Due to NEt3 mediated isomerization also mixtures of α,β- and β,γ-unsaturated nitroalkenes can be deployed in this reaction. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the asymmetric hydrogenation of β,β-disubstituted nitroalkenes by using chiral bisphosphine-thiourea ligand published in the journal "Organic Letters" in 2013.

An abstract of the article "Rhodium-Catalyzed Asymmetric Hydroformylation of 1,1-Disubstituted Allylphthalimides: A Catalytic Route to β3-Amino Acids" by X. Zheng and colleagues is presented.

Ligand (I) gives good results in the title reaction. [ABSTRACT FROM AUTHOR]