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A novel synthetic route was developed for the construction of chiral cis-vicinal halohydrins derivatives through Ir/f-phamidol-catalysed asymmetric hydrogenation of corresponding α-halogenated ketones with high yields (up to 99% yield), excellent diastereoselectivities (>20 : 1 dr), enantioselectivities (up to 99% ee), and high substrate catalyst ratio (S/C = 1000). [ABSTRACT FROM AUTHOR]

Chiral primary amines widely exist in drugs and are exceptionally important subunits or synthons in the syntheses of chiral secondary and tertiary amines of medicinal interest. Metal-catalyzed enantioselective reductive amination (ERA) of ketones with ammonium salts or ammonia provides a direct method for their synthesis. Although very useful, progress in this field has been very slow and important advances have only been achieved in the last few years. Several major challenges exist in this reaction, including (1) the reversible formation of unstable NH-imine intermediates; (2) the strong coordination property of N-containing reagents toward metal species; and (3) the lack of efficient catalytic systems that enable high enantiocontrol. Generally, the efficiency and enantiocontrol of this reaction is dependent on the substrate type, for instance, the use of α-keto esters/amides or aryl alkyl ketones is well established and they have even been used in the industrial production of chiral amine drugs. However, highly enantioselective control in dialkyl ketones, cyclic ketones, and α-keto acids remains unsolved. Herein, the historical development of ERA reactions with ammonium salts or ammonia gas is summarized, and novel synthetic applications toward useful synthons or drugs are presented. In addition, the factors restricting the growth of this method are also discussed. 1 Introduction 2 Enantioselective Reductive Amination via Hydrogenation 2.1 Enantioselective Reductive Amination of β-Keto Esters/Amides 2.2 Enantioselective Reductive Amination of Simple Ketones 2.3 Enantioselective Reductive Amination of α-Functionalized Ketones 2.4 Enantioselective Reductive Amination/Cyclization Cascade Reactions 2.5 Others 3 Enantioselective Reductive Amination via Transfer Hydrogenation 4 Synthetic Applications 5 Conclusions and Outlook [ABSTRACT FROM AUTHOR]

High enantioselectivities (up to 99% ee) have been observed for the catalytic asymmetric hydrogenation of the α-ketone enol acetates. DuanPhos has been proved to be the most effective ligand for this reaction. The high yield and enantioselectivity of the asymmetric hydrogenation of the α-ketone enol acetates represents a feasible synthetic route to important pharmaceutical building blocks: α-hydroxy ketones. [ABSTRACT FROM AUTHOR]

Abstract: Among the bisphosphine ligands, we have previously developed C n -TunePhos (n =1–6) as a family of ligands with tunable bite angles. The increase in spacer –CH2– groups in this family of ligands causes changes in ligand dihedral angle, which in turn causes P–Pd–P bite angle variation. Pd-catalyzed asymmetric alkylations and cycloadditions have been tested with C n -TunePhos ligands. This study aims at a possible correlation between ligand bite angles with enantioselectivity of the Pd-catalyzed asymmetric products. [Copyright &y& Elsevier]

A series of new chiral mono- or bidentate phosphorus ligands were efficiently prepared through a key intermediate (S)-4-chloro-4,5-dihydro-3H-4-phosphacyclohepta[2,1-a;3,4-a′]binaphthalene and its derivatives. These ligands were applied in the Rh-catalyzed asymmetric hydrogenation of α-dehydro amino acids, enol acetates, itaconates, and enamides. Good to excellent enantioselectivities were obtained (up to 99.5% ee). [Copyright &y& Elsevier]

Palladium-catalyzed homocoupling reaction of aryl boronic acids has been developed using a protocol similar to the well-documented crosscoupling reaction. α-Halocarbonyl compounds are applied to initiate the reaction via oxidative addition to a palladium(0) species. The resulting palladium enolate halide can promote the double transmetallation. Reductive elimination generates the desire homocoupling product. [Copyright &y& Elsevier]

Details a study on the enantioselective Rh-catalyzed hydrogenation of enamides using the BICP ligand. Results and discussion; Features of the Rh-BICP catalyst; Scope of asymmetric hydrogenation reaction; Characterization of substrates; General procedure for asymmetric hydrogenation.

Describes the synthesis and characterization of a series of iron and cobalt `picnic basket' porphyrins. Dioxygen binding to iron and cobalt picnic basket porphyrins; Increase in oxygen affinity as basket size decreases; Influence of a dipole-dipole interaction between the terminally bound dioxygen and the amide protons on the stability of the oxygen adducts.

Discusses the regioselective and enantioselective epoxidations catalyzed by metalloporphyrins. Explanation of the biomimetic antecedents and relevance to synthetic applications; Classification of the catalysts.

Looks at the enantioselective rhodium-catalyzed hydrogenation of dehydroamino acids with chiral bisphosphinites. Reference to the asymmetric synthesis of transition metal; Characteristics of chiral phospine; Methods used to conduct experiments; Discussion of results attained in experiments.

Abstract: A new six-membered bis(azaphosphorinane) ligand has been readily prepared starting from an inexpensive chiral epoxide; excellent enantioselectivities (up to over 99% ee) have been achieved in the Rh-catalyzed asymmetric hydrogenations of β-dehydroamino acid derivatives and α-arylenamides. [Copyright &y& Elsevier]

Owing to their distinctive 1,3‐dipolar structure, the catalytic asymmetric hydrogenation of nitrones to hydroxylamines has been a formidable and longstanding challenge, characterized by intricate enantiocontrol and susceptibility to N−O bond cleavage. In this study, the asymmetric hydrogenation and transfer hydrogenation of nitrones were accomplished with a tethered TsDPEN‐derived cyclopentadienyl rhodium(III) catalyst (TsDPEN: p‐toluenesulfonyl‐1,2‐diphenylethylene‐1,2‐diamine), the reaction proceeds via a novel 7‐membered cyclic transition state, producing chiral hydroxylamines with up to 99 % yield and >99 % ee. The practical viability of this methodology was underscored by gram‐scale catalytic reactions and subsequent transformations. Furthermore, mechanistic investigations and DFT calculations were also conducted to elucidate the origin of enantioselectivity. [ABSTRACT FROM AUTHOR]

Owing to their distinctive 1,3‐dipolar structure, the catalytic asymmetric hydrogenation of nitrones to hydroxylamines has been a formidable and longstanding challenge, characterized by intricate enantiocontrol and susceptibility to N−O bond cleavage. In this study, the asymmetric hydrogenation and transfer hydrogenation of nitrones were accomplished with a tethered TsDPEN‐derived cyclopentadienyl rhodium(III) catalyst (TsDPEN: p‐toluenesulfonyl‐1,2‐diphenylethylene‐1,2‐diamine), the reaction proceeds via a novel 7‐membered cyclic transition state, producing chiral hydroxylamines with up to 99 % yield and >99 % ee. The practical viability of this methodology was underscored by gram‐scale catalytic reactions and subsequent transformations. Furthermore, mechanistic investigations and DFT calculations were also conducted to elucidate the origin of enantioselectivity. [ABSTRACT FROM AUTHOR]

[Display omitted] The asymmetric hydrogenation of imines has been well-established; however, the asymmetric hydrogenation of oximes and oxime ethers with the retention of N O bonds remains a significant challenge in the realm of asymmetric hydrogenation, due to the low reactivity and the difficulty in control of stereoselectivity. Catalytic asymmetric hydrogenation of oximes or oxime ethers represents one of the most direct and efficient method for the construction of chiral hydroxylamines, which are key structural motifs in a wide range of bioactive compounds and pharmaceuticals. This review describes the recent progress in the development of catalytic asymmetric hydrogenation of oximes and oxime ethers. We hope that this review will inspire the development of new synthetic strategies for the asymmetric synthesis of chiral hydroxylamines. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Transition metal‐catalyzed asymmetric transfer hydrogenation has been proven to be a powerful approach for the synthesis of chiral alcohols. Herein, a highly efficient and enantioselective transfer hydrogenation of dibenzoheptaheterocyclic ketones catalyzed by an arene‐tethered TsDPEN‐based Rh(III) catalyst has been successfully developed, and a variety of dibenzoheptaheterocyclic ketones were reduced by a 1/1 mixture of formic acid and DBU (1,8‐diazabicyclo[5.4.0]undec‐7‐ene) with high yields and enantioselectivities. With this method, the asymmetric reduction of 7,8‐difluorodibenzo[b,e]thiepin‐11(6H)‐one has been realized, providing the key intermediate of baloxavir marboxil with >99% yield and >99% ee at a substrate/catalyst molar ratio of 1000. [ABSTRACT FROM AUTHOR]

This review provides a comprehensive view of the application of first-row transition metals in asymmetric hydrogenation and asymmetric transfer hydrogenation. The catalytic behavior of 3d metals is significantly different from that of 4d and 5d metals. The replacement of noble metals with first-row transition metals has encountered challenges such as different reaction mechanisms and unexpected deactivation of the catalyst. The potential involvement of a single-electron process has been the most notorious feature of first-row metals. This review aims to give readers a picture of how first-row transition metals catalyze hydrogenation reactions and the corresponding enantioinduction models. Although this article is partitioned according to the substrate type, it is mechanism-oriented and is focused on catalytic systems. A certain catalytic system could be applied in the hydrogenation of different types of double bonds. Similarities within first-row metals and differences from their 4d and 5d congeners were emphasized. [ABSTRACT FROM AUTHOR]

We herein reported the design and synthesis of a ferrocene‐based tetradentate ligand that is featured with modular synthesis and rigid skeleton. Its iron(II) complex facilitates asymmetric direct hydrogenation of ketones without the participation of extra strong‐field ligand such as CO and isocyanide. Hydride donor lithium aluminum hydride (LAH) converted non‐reactive Fe(II) species to reactive Fe(II) hydride species. With this catalyst, various chiral alcohols including the intermediate for montelukast could be prepared with satisfactory yields and enantioinduction. [ABSTRACT FROM AUTHOR]

Iridium/f‐Amphol‐catalyzed asymmetric hydrogenation of various benzo‐fused five to seven‐membered cyclic ketones was successfully developed, affording a series of chiral benzo‐fused cyclic alcohols with excellent results (75%–99% yields, 93%–>99% ee, and TON up to 297 000). The enantioenriched products can be employed as key intermediates or motifs for the synthesis of some important biologically active compounds, such as rasagiline mesylate TVP‐1012 used for the treatment of Parkinson's disease, the enantiomer of anticonvulsant drug eslicarbazepine acetate (BIA 2‐093). [ABSTRACT FROM AUTHOR]

Describes a method of preparing analogues of several heme protein active sites. Use of Michael acceptors in fixed geometries around the porphyrin plane; Preparation of acrylamides from atropisomers of tetrakis (omega-aminophenyl) porphyrin; Synthesis of biomimetic model hemes using congruent multiple Michael addition.

The atom‐ and step‐efficient synthesis of chiral fused tricyclic lactams from readily available ketoesters using cheap ammonium salts as the nitrogen source is reported. This ruthenium‐catalyzed system operates through an efficient tandem dynamic kinetic asymmetric reductive amination (ARA)/lactamization and produces chiral fused tricyclic lactams in high yields with excellent diastereo‐ and enantioselectivity (up to >99 % ee, >20 : 1 dr and 98 % yield). The robust method was also applied to the concise synthesis of key intermediates in the synthesis of rivastigmine analogues and chiral N‐heterocyclic carbene catalysts. [ABSTRACT FROM AUTHOR]

The atom‐ and step‐efficient synthesis of chiral fused tricyclic lactams from readily available ketoesters using cheap ammonium salts as the nitrogen source is reported. This ruthenium‐catalyzed system operates through an efficient tandem dynamic kinetic asymmetric reductive amination (ARA)/lactamization and produces chiral fused tricyclic lactams in high yields with excellent diastereo‐ and enantioselectivity (up to >99 % ee, >20 : 1 dr and 98 % yield). The robust method was also applied to the concise synthesis of key intermediates in the synthesis of rivastigmine analogues and chiral N‐heterocyclic carbene catalysts. [ABSTRACT FROM AUTHOR]

By combining the concept of flash chemistry and radial synthesis, a novel microreactor (Flashstop reactor) was designed to study isomerization process of hydroformylation by a Rh/tetraphosphite catalyst in a time scale of seconds. It was found that in the initial 313 seconds, 60–99 % of 1‐octene was isomerized to 2‐ and 3‐octenes before the formation of aldehydes. Within this period, two different types of isomerization reactions were observed. It was proposed that a monohydride complex without CO ligand accounts for the ultrafast isomerization in the initial 30 seconds. The isomerization rate with such monohydride species was calculated much faster than that with the well‐known H(CO)Rh(P−P) species. Both experimental and DFT computational studies were carried out to support this assumption. Fast transformations early on in catalytic cycles have been rarely studied due to the lack of proper tools. We believe that the Flashstop reactor is a powerful tool for analysis of kinetics in gas‐liquid biphasic reactions within a time scale of seconds to minutes. [ABSTRACT FROM AUTHOR]

By combining the concept of flash chemistry and radial synthesis, a novel microreactor (Flashstop reactor) was designed to study isomerization process of hydroformylation by a Rh/tetraphosphite catalyst in a time scale of seconds. It was found that in the initial 313 seconds, 60–99 % of 1‐octene was isomerized to 2‐ and 3‐octenes before the formation of aldehydes. Within this period, two different types of isomerization reactions were observed. It was proposed that a monohydride complex without CO ligand accounts for the ultrafast isomerization in the initial 30 seconds. The isomerization rate with such monohydride species was calculated much faster than that with the well‐known H(CO)Rh(P−P) species. Both experimental and DFT computational studies were carried out to support this assumption. Fast transformations early on in catalytic cycles have been rarely studied due to the lack of proper tools. We believe that the Flashstop reactor is a powerful tool for analysis of kinetics in gas‐liquid biphasic reactions within a time scale of seconds to minutes. [ABSTRACT FROM AUTHOR]

Review: 232 refs. [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]

Asymmetric hydroformylation represents one of the most efficient routes for the preparation of chiral aldehydes from alkenes in the presence of syngas in a perfect atom-economic way. During the past few decades, a variety of chiral ligands have been developed for the asymmetric hydroformylation. However, only a few ligands exhibit good performance in terms of the regio- and enantioselectivities. Additionally, for the chiral ligands developed up to now, only limited substrates were tolerated and no examples have led to the application of the asymmetric hydroformylation reaction on a commercial scale due to several technical challenges. This account provides a brief introduction of the current efficient chiral ligands for asymmetric hydroformylation and the ongoing efforts we have made in this field. [ABSTRACT FROM AUTHOR]

Arene hydrogenation is the most straightforward method to prepare carbo‐ and heterocycles. However, the high resonance energy prevents aromatic substrates from hydrogenation. Herein the homogeneous, nucleophilic hydrogenation of less electron‐rich arenes and heteroarenes is reported. The Co(P4N2)H species that has been demonstrated to be a strong hydride donor could deliver a hydride ion to the cyano (hetero)arene substrates. Deuterium labeling experiments supported a Michael‐type reaction pathway. Theoretical analyses have been conducted to investigate the hydricity of the catalytically active CoH species and the electrophilicity of the arene substrates. An outlook for the synthesis of more challenging substituted benzenes was proposed based on the in silico modification of the CoH species. [ABSTRACT FROM AUTHOR]

[Display omitted] • One iron catalyst showing multiple chemoselectivity. • General substrate scope (up to 56 example) and excellent selectivity (99% yield & selectivity) • High efficiency towards aldehydes (TONs up to 100,000) • Excellent functional group tolerance. Hydrogenation of different types of unsaturated substrates with a single catalyst has always been a challenge for transition-metal-based catalysts. In this paper, an iron tetraphosphine complex shows high catalytic efficiency for selective hydrogenation of aldehydes, conjugated ketones and nitroarenes in the presence of other easily reduced functional groups like ketone, alkenyl, ester and alkynyl groups. The catalytic efficiency, chemoselectivity and robustness of this Fe/P2C‑PPh2 2 NBn 2 catalyst found its merit in the preparation of several important drug intermediates. A diamagnetic trans -iron dihydride complex formed under the reaction conditions was supposed to be an on-cycle catalytically active species. We are looking forward to the application of this method in pharmaceutical and fine chemical industries. [ABSTRACT FROM AUTHOR]

Chiral β-heteroaryl amino alcohols are key fragments of many bioactive compounds and antibiotics, and the development of efficient synthetic methods for these compounds is of great value. The highly enantioselective hydrogenation of α-N-heteroaryl ketones was realized with a ruthenium-diphosphine–diamine catalyst, providing the corresponding chiral β-heteroaryl amino alcohols with up to 99% yield and up to >99% ee. The synthetic utilities of the current reaction were demonstrated by gram-scale synthesis of key intermediates of Sertaconazole and Cenobamate. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrafast isomerization-hydroformylation of C4 raffinate with high regioselectivity. • Remarkably low reaction temperature. • Coordinating enhancement of the tetraphosphite ligand. • Hydrolytically stable catalyst for continuous production of n -valeraldehyde. Ultrafast linear selective isomerization-hydroformylation (ISO-HF) tandem reaction under mild conditions remains a challenge. Herein, a novel tetraphosphite ligand (TBTP) and its application in ISO-HF of C4 Raffinate were reported. Based on a biphenol-2,2′,6,6′-tetraol with sterically demanding tert -butyl substituents, TBTP can be readily prepared by the reaction of biphenyl phosphorchloridite and tetraol in kilogram scale. The structural and coordinating features of this ligand and its rhodium complex were studied by XRD, NMR and DFT calculations. This tetraphosphite ligand showed high turnover frequencies and regioselectivities in the rhodium-catalyzed ISO-HF of trans -, cis- 2-butene. Such hydrolytically stable ligand was successfully applied in the ISO-HF of etherified C4 feed under a mild condition (65 °C, 7 bar syngas, TOF up to 1574 h−1, ∼95% linear selectivity). An over-14-day durability test that was operated in two 5-L continuously stirred-tank reactors (CSTRs) in series delivered 79 kg n -valeraldehyde for the manufacture of C10 plasticizer DPHP. [ABSTRACT FROM AUTHOR]

The first rhodium‐catalyzed highly chemo‐, regio‐ and enantioselective hydroformylation of cyclopropyl‐functionalized trisubstituted alkenes affording useful chiral cyclopropyl entities is reported. Compared to generally used diphosphine ligands for asymmetric catalysis, the modified hybrid phosphorus ligand, named (R,S)‐DTBM‐Yanphos, can convert a series of readily available cyclopropyl‐functionalized trisubstituted alkenes into high‐value chiral cyclopropyl‐functionalized aldehydes with high selectivities (81–98 % ee). Gram‐scale reactions (TON up to 1500) and follow‐up transformations to the corresponding alcohol, acid, esters and nitrile are also presented. Finally, a possible hydroformylation mechanism involving ring‐open‐hydroformylation pathways is proposed based on control and deuteroformylation reactions. [ABSTRACT FROM AUTHOR]

The first rhodium‐catalyzed highly chemo‐, regio‐ and enantioselective hydroformylation of cyclopropyl‐functionalized trisubstituted alkenes affording useful chiral cyclopropyl entities is reported. Compared to generally used diphosphine ligands for asymmetric catalysis, the modified hybrid phosphorus ligand, named (R,S)‐DTBM‐Yanphos, can convert a series of readily available cyclopropyl‐functionalized trisubstituted alkenes into high‐value chiral cyclopropyl‐functionalized aldehydes with high selectivities (81–98 % ee). Gram‐scale reactions (TON up to 1500) and follow‐up transformations to the corresponding alcohol, acid, esters and nitrile are also presented. Finally, a possible hydroformylation mechanism involving ring‐open‐hydroformylation pathways is proposed based on control and deuteroformylation reactions. [ABSTRACT FROM AUTHOR]

Owing to the biological significance and great synthetic value of chiral lactones and their derivatives, increasing attention has been paid to developing effective synthetic methods for chiral lactones. We herein report an efficient asymmetric hydrogenation of benzo-fused ketoesters, γ-ketoesters and biaryl-bridged ketoesters catalyzed by chiral iridium complexes bearing ferrocene-based chiral ligands, furnishing a series of chiral lactones in superb yields and excellent enantioselectivities (up to 99% yields and up to 99% ee). [ABSTRACT FROM AUTHOR]

The bisphosphine ligand 1c is highly efficient and selective for the asymmetric hydroformylation (AHF) of dihydrofuran and pyrrolines. The AHF of 2,3-dihydrofuran yielded the 2-carbaldehyde in up to 93% ee. The remarkable highest regioselectivity of 2,5-dihydrofuran was obtained to date up to 499 β-isomer/α-isomer with ligand 1c . Furthermore, the highest 96% and 92% ee values were accomplished using the same catalytic system in the AHF of N -Boc pyrroline 11 and 14 . [ABSTRACT FROM AUTHOR]

An unprecedented highly enantioselective Ru‐catalyzed direct asymmetric reductive amination of α‐keto amides with ammonium salts has been disclosed, efficiently offering valuable enantioenriched N‐unprotected unnatural α‐amino acid derivatives bearing a broad range of aryl or alkyl α‐substituents. This protocol features easily accessible substrates, good functional‐group tolerance and excellent enantiocontrol, making it a good complementary approach to the known methods. Moreover, this method is also applicable to the preparation of N‐unprotected unnatural α‐amino acid derivatives containing an additional stereogenic center at the β‐position through a dynamic kinetic resolution (DKR) process. Convenient transformations of the obtained products into chiral N‐unprotected unnatural α‐amino acids, drug intermediates, peptides, and organocatalysts/ligands further showcase the utility of this method. [ABSTRACT FROM AUTHOR]

An unprecedented highly enantioselective Ru‐catalyzed direct asymmetric reductive amination of α‐keto amides with ammonium salts has been disclosed, efficiently offering valuable enantioenriched N‐unprotected unnatural α‐amino acid derivatives bearing a broad range of aryl or alkyl α‐substituents. This protocol features easily accessible substrates, good functional‐group tolerance and excellent enantiocontrol, making it a good complementary approach to the known methods. Moreover, this method is also applicable to the preparation of N‐unprotected unnatural α‐amino acid derivatives containing an additional stereogenic center at the β‐position through a dynamic kinetic resolution (DKR) process. Convenient transformations of the obtained products into chiral N‐unprotected unnatural α‐amino acids, drug intermediates, peptides, and organocatalysts/ligands further showcase the utility of this method. [ABSTRACT FROM AUTHOR]

A phosphine‐catalyzed highly enantioselective and diastereoselective (up to 98 % ee and >20 : 1 dr) (3+2) annulation between vinylcyclopropanes and N‐tosylaldimines has been developed, which allows facile access to a range of highly functionalized chiral pyrrolidines. Notably, this method makes use of vinylcyclopropanes as a synthon for phosphine‐mediated asymmetric annulation reaction, which will offer new opportunities for potential applications of cyclopropanes substrates in phosphine‐catalyzed organic transformations. [ABSTRACT FROM AUTHOR]

A phosphine‐catalyzed highly enantioselective and diastereoselective (up to 98 % ee and >20 : 1 dr) (3+2) annulation between vinylcyclopropanes and N‐tosylaldimines has been developed, which allows facile access to a range of highly functionalized chiral pyrrolidines. Notably, this method makes use of vinylcyclopropanes as a synthon for phosphine‐mediated asymmetric annulation reaction, which will offer new opportunities for potential applications of cyclopropanes substrates in phosphine‐catalyzed organic transformations. [ABSTRACT FROM AUTHOR]

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]

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]

ABSTRACT Novel synthesis of P-chiral 1,3-oxaphospholane starting from optically pure propylene oxide is described. The exact structure is confirmed by X-ray crystallographic analysis. [ABSTRACT FROM AUTHOR]

A novel synthetic route was developed for the construction of a chiral cis-hexahydro-γ-carboline derivative through Ir/ZhaoPhos-catalyzed asymmetric hydrogenation of corresponding tetrahydro-γ-carboline with high yields (up to 99% yield), excellent diastereoselectivities (up to >99 : 1 dr) and enantioselectivities (up to 99% ee), and high substrate-to-catalyst ratios (up to 5000). [ABSTRACT FROM AUTHOR]

We report an efficient and straightforward method to synthesize enantio-enriched N-unprotected α-amino acetals via ruthenium-catalyzed direct asymmetric reductive amination. The α-amino acetal products are versatile and valuable platform molecules that can be converted to the corresponding α-amino acids, amino alcohols, and other derivatives by convenient transformations. [ABSTRACT FROM AUTHOR]

Owing to the biological significance and great synthetic value of 1,4-diarylbutane-1,4-diols and their derivatives, increasingly considerable attention has been paid to developing effective synthetic methods for chiral 1,4-diarylbutane-1,4-diols. We herein report an efficient asymmetric hydrogenation of 1,4-diaryldiketones catalyzed by a chiral iridium complex bearing f-amphox as ligand, furnishing a series of 1,4-diarylbutane-1,4-diols in excellent yields (up to >99%) with exceptional enantioselectivities (up to >99.9% ee) and diastereoselectivities (up to >100 : 1 dr). [ABSTRACT FROM AUTHOR]

Der direkte Weg: Ausgehend von leicht zugänglichen Ausgangsstoffen gelang die effiziente Synthese chiraler allylischer Amine und aliphatischer Amine mithilfe einer Rhodium ‐ katalysierten asymmetrischen Hydrierung. Ein chirales Z ‐ allylisches Amin wurde zum ersten Mal in einer von Rhodium/DuanPhos katalysierten asymmetrischen Hydrierung erhalten. TMS=Trimethylsilyl, cod=Cyclooctadien, TON=Umsatzzahl. [ABSTRACT FROM AUTHOR]

The direct route: A Rhodium‐catalyzed asymmetric hydrogenation method for the efficient synthesis of a broad range of chiral allylic amines and aliphatic amines from readily available materials was developed. A chiral Z‐allylic amine was obtained for the first time through a Rhodium–DuanPhos‐catalyzed asymmetric hydrogenation. TMS=Trimethylsilyl, cod=cyclooctadiene, TON=turnover number. [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]

Abstract: A new type of chiral phosphine–quinoline ligand bearing a spiro[4,4]-1,6-nonadiene scaffold was designed and synthesized. Its cationic iridium complex has been characterized by X-ray diffraction analysis and evaluated in the catalytic asymmetric hydrogenation of alkene and imine derivatives, giving the corresponding hydrogenation products with high activity albeit moderate enantioselecitivity. [ABSTRACT FROM AUTHOR]

Abstract: A new class of C 1-symmetric bisphosphine ligands with three hindered quadrants have been obtained through facile synthesis from chiral BINOL derivatives. Their rhodium complexes have exhibited high enantioselectivities (up to 98% ee) in the asymmetric hydrogenation of various unsaturated prochiral olefins, providing an efficient catalytic system for the enantioselective synthesis of chiral amino acids and amines. [Copyright &y& Elsevier]