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The regio- and enantioselective functionalization of 1,3-dienes has become a powerful tool for the synthesis of allylic compounds, yet it remains a challenge for aliphatic dienes. Herein, we report...

An iridium catalyzed asymmetric hydrogenation of racemic exocyclic γ,δ-unsaturated β-ketoesters via dynamic kinetic resolution to functionalized chiral allylic alcohols was developed. With the chiral spiro iridium catalysts Ir-SpiroPAP, a series of racemic exocyclic γ,δ-unsaturated β-ketoesters bearing a five-, six-, or seven-membered ring were hydrogenated to the corresponding functionalized chiral allylic alcohols in high yields with good to excellent enantioselectivities (87 to >99% ee) and cis-selectivities (93 : 7 to >99 : 1). The origin of the excellent stereoselectivity was also rationalized by density functional theory calculations. Furthermore, this protocol could be performed on gram scale and at a lower catalyst loading (0.002 mol%) without the loss of reactivity and enantioselectivity, and has been successfully applied in the enantioselective synthesis of chiral carbocyclic δ-amino esters and the β-galactosidase inhibitor isogalactofagomine., An iridium catalyzed asymmetric hydrogenation of exocyclic γ,δ-unsaturated β-ketoesters via dynamic kinetic resolution was developed, providing efficient protocol for enantioselective synthesis of functionalized chiral allylic alcohols.

Although the transition metal-catalyzed asymmetric hydrogenation of aromatic ketones has been extensively explored, the enantioselective hydrogenation of aliphatic ketones remains a challenge becau...

Catalytic enantioselection usually depends on differences in steric interactions between prochiral substrates and a chiral catalyst. We have discovered a carbene Si-H insertion in which the enantioselectivity depends primarily on the electronic characteristics of the carbene substrate, and the log(er) values are linearly related to Hammett parameters. A new class of chiral tetraphosphate dirhodium catalysts was developed; it shows excellent activity and enantioselectivity for the insertion of diarylcarbenes into the Si-H bond of silanes. Computational and mechanistic studies show how the electronic differences between the two aryls of the carbene lead to differences in energies of the diastereomeric transition states. This study provides a new strategy for asymmetric catalysis exploiting the electronic properties of the substrates.

An efficient asymmetric hydrogenation of racemic α-aryl-s-ethoxycarbonyl cyclopentanones via dynamic kinetic resolution is reported. Via catalysis by a chiral iridium Ir-SpiroPAP catalyst, a range of racemic α-aryl-s-ethoxycarbonyl cyclopentanones were hydrogenated to the corresponding ester-functionalized chiral 2-arylcyclopentanols with three contiguous stereocenters in high yields with excellent enantio- and diastereoselectivities. This method was successfully applied in the enantioselective synthesis of cyclopentane-based I³-amino ester/alcohol derivatives and phenylpropanoid (+)-burmaniol A.

A highly enantioselective Si-H bond insertion reaction of α-aryldiazoacetates catalyzed by chiral spiro dirhodium tetraphosphate was developed. Various chiral α-silyl esters were prepared with high yield (up to 92%) and excellent enantioselectivity (up to >99% ee) through this protocol. It is noteworthy that the 2-substituted aryl diazoacetates, which are challenging substrates for other chiral dirhodium catalysts, also exhibited good results in this reaction. This work represents one of the few successful applications of chiral dirhodium phosphates in asymmetric catalysis.

A tag team approach to forming C–N bonds Many pharmaceutical compounds contain carbon-nitrogen (C–N) bonds in just one of two mirror-image orientations. Forging these bonds with electron-rich nitrogen reactants is challenging because the nitrogen groups can coordinate with, and thus interfere with, the catalyst. Li et al. report a cooperative approach to overcoming this obstacle (see the Perspective by Ovian and Jacobsen). They used a copper catalyst to activate the carbon reactant and then a hydrogen-bonding thiourea catalyst to set the product geometry with high selectivity. The reaction is compatible with a broad range of diazo ester and amine coupling partners. Science , this issue p. 990 ; see also p. 948

We report an enantioselective hydroarylation reaction of styrenes and 1,3-dienes with arylboronic acids catalyzed by nickel complexes bearing chiral spiro aminophosphine ligands. The reaction serve...

Asymmetric Friedel–Crafts conjugate addition reactions that generate an α-chiral center are challenging because the configuration-determining step is a proton-transfer reaction of a highly active e...

A protocol for highly enantioselective hydrogenation of racemic α-arylamino lactones with catalysis by site-specifically modified chiral spiro iridium complexes has been developed. With the optimized catalyst, racemic α-arylamino-γ-lactones and α-arylamino-δ-lactones could be hydrogenated to the corresponding chiral 2-amino diols with good to excellent enantioselectivities.

A scalable enantioselective total synthesis of (-)-goniomitine has been developed by using an iridium-catalyzed asymmetric hydrogenation of an exocyclic enone ester to control the configuration of the molecule. The synthesis begins from commercially available starting materials, and proceeds through an integrated asymmetric ketone hydrogenation, Johnson-Claisen rearrangement, and one-pot oxidation/deprotection/cyclization process. With this highly efficient and scalable strategy, (-)-goniomitine was synthesized in eleven steps with 27 % overall yield, and formal enantioselective syntheses of (+)-1,2-dehydroaspidospermidine, (+)-aspidospermidine, and (+)-vincadifformine were also achieved.

A highly enantioselective and diastereoselective nickel-catalyzed desymmetrizing cyclization of 1,6-dienes was developed by using chiral spiro phosphoramidite ligands. The reaction provides a new atom- and step-economical approach to chiral spiro lactones and analogues bearing a quaternary stereocenter.

The Nazarov electrocyclization reaction is a convenient, widely used method for construction of cyclopentenones. In the past few decades, catalytic asymmetric versions of the reaction have been extensively studied, but the strategies used to control the position of the double bond limit the substituent pattern of the products and thus the synthetic applications of the reaction. Herein, we report highly enantioselective silicon-directed Nazarov reactions which were cooperatively catalyzed by a Lewis acid and a chiral Bronsted acid. The chiral cyclopentenones we synthesized using this method generally cannot be obtained by means of other catalytic enantioselective reactions, including previously reported methods for enantioselective Nazarov cyclization. The silicon group in the dienone substrate stabilized the β-carbocation of the intermediate, thereby determining the position of the double bond in the product. Mechanistic studies suggested that the combination of Lewis and Bronsted acids synergistically activated the dienone substrate and that the enantioselectivity of the reaction originated from a chiral Bronsted acid promoted proton transfer reaction of the enol intermediate.

Herein we report the first enantioselective total syntheses of pentacyclic homoproaporphine alkaloids by means of a route, which includes a tandem retro-oxa-Michael addition and nucleophilic substitution to generate the oxa-benzobicyclco[3.3.1]nonane core structure, a Pictet-Spengler cyclization to construct the fused B and C rings, and sequential Baeyer-Villiger oxidation and pinacol-type cyclization to install the hydroxyl-lactol moiety of D ring. With this unified route, six pentacyclic homoproaporphine alkaloids have been synthesized enantioselectively.

Catalytic asymmetric reactions in which water is a substrate are rare. Enantioselective transition-metal-catalyzed insertion of carbenes into the O-H bond of water can be used to incorporate water into the stereogenic center, but the reported chiral catalysts give good results only when α-aryl-α-diazoesters are used as the carbene precursors. Herein we report the first highly enantioselective O-H bond insertion reactions between water and α-alkyl- and α-alkenyl-α-diazoesters as carbene precursors, with catalysis by a combination of achiral dirhodium complexes and chiral phosphoric acids or chiral phosphoramides. Participation of the phosphoric acids or phosphoramides in the carbene transfer reaction markedly suppressed competing side reactions, such as β-H migration, carbene dimerization, and olefin isomerization, and thus ensured good yields of the desired products. Fine-tuning of the ester moiety facilitated enantiocontrol of the proton transfer reactions of the enol intermediates and resulted in excellent enantioselectivity. This protocol represents an efficient new method for preparation of multifunctionalized chiral α-alkyl and α-alkenyl hydroxyl esters, which readily undergo various transformations and can thus be used for the synthesis of bioactive compounds. Mechanistic studies revealed that the phosphoric acids and phosphoramides promoted highly enantioselective [1,2]- and [1,3]-proton transfer reactions of the enol intermediates. Maximization of molecular orbital overlap in the transition states of the proton transfer reactions was the original driving force to involve the proton shuttle catalysts in this process.

A highly efficient asymmetric hydrogenation of γ- and δ-ketoacids was developed by using a chiral spiro iridium catalyst (S)-1a, affording the optically active γ- and δ-hydroxy acids/lactones in high yields with excellent enantioselectivities (up to >99% ee) and turnover numbers (TON up to 100000). This protocol provides an efficient and practical method for enantioselective synthesis of Ezetimibe.

Transition metal-catalyzed carbene insertion into X-H bonds (X = N, O, S, and C) represents a typical carbene transfer reaction and has been widely used in organic synthesis. The enantioselectivity-determining step in some of these insertion reactions is the proton transfer of active intermediates such as ylides, metal enolates, or free enols. Since most of the traditional chiral transition metal catalysts tend to dissociate from these active intermediates and cannot be involved in the proton-transfer step, enantiocontrol of these insertion reactions has long been a challenging task. Since 2011, we have developed chiral spiro phosphoric acids as chiral proton-transfer shuttle (CPTS) catalysts, which have been proven to be efficient catalysts for the proton transfer of active intermediates in carbene insertion reactions. Upon combining with achiral dirhodium catalysts, the CPTS catalysts accomplish highly enantioselective insertions of N-H, S-H, and C-H bonds. Herein, a number of important chiral building blocks, including α-amino acid derivatives, α-amino ketones, α-thioesters, and α,α-diaryl acetates, were prepared with high yields and high enantioselectivities through these insertion reactions.

We have achieved the first concise, divergent, asymmetric total syntheses of mulinane diterpenoids. Specifically, we developed a new strategy featuring a key intramolecular Friedel-Crafts reaction to construct the chiral fused 5-6-6 tricyclic motif, followed by sequential Birch reduction, conjugate methylation, and homologation/ring-expansion reactions to furnish the desired 5-6-7 tricyclic skeleton bearing five contiguous stereocenters. With this efficient strategy, seven mulinane diterpenoids and two analogues were synthesized via late-stage functional modification or functionalization in 8.6-20% overall yields and 11-15 steps

Chiral carboxylic acid moieties are widely found in pharmaceuticals, agrochemicals, flavors, fragrances, and health supplements. Although they can be synthesized straightforwardly by transition-metal-catalyzed enantioselective hydrogenation of unsaturated carboxylic acids, because the existing chiral catalysts have various disadvantages, the development of new chiral catalysts with high activity and enantioselectivity is an important, long-standing challenge. Ruthenium complexes with chiral diphosphine ligands and rhodium complexes with chiral monodentate or bidentate phosphorus ligands have been the predominant catalysts for asymmetric hydrogenation of unsaturated acids. However, the efficiency of these catalysts is highly substrate-dependent, and most of the reported catalysts require a high loading, high hydrogen pressure, or long reaction time for satisfactory results. Our recent studies have revealed that chiral iridium complexes with chiral spiro-phosphine-oxazoline ligands and chiral spiro-phosphine-benzylamine ligands exhibit excellent activity and enantioselectivity in the hydrogenation of α,β-unsaturated carboxylic acids, including α,β-disubstituted acrylic acids, trisubstituted acrylic acids, α-substituted acrylic acids, and heterocyclic α,β-unsaturated acids. On the basis of an understanding of the role of the carboxy group in iridium-catalyzed asymmetric hydrogenation reactions, we developed a carboxy-group-directed strategy for asymmetric hydrogenation of olefins. Using this strategy, we hydrogenated several challenging olefin substrates, such as β,γ-unsaturated carboxylic acids, 1,1-diarylethenes, 1,1-dialkylethenes, and 1-alkyl styrenes in high yield and with excellent enantioselectivity. All these iridium-catalyzed asymmetric hydrogenation reactions feature high turnover numbers (up to 10000) and turnover frequencies (up to 6000 h

Herein, we report transition-metal-catalyzed B-H bond insertion reactions between borane adducts and alkynes to afford organoboron compounds in excellent yields under mild reaction conditions. This successful use of alkynes as carbene precursors in these reactions constitutes a new route to organoboron compounds. The starting materials are safe and readily available, and the reaction exhibits 100% atom-economy. Moreover, an asymmetric version catalyzed by chiral dirhodium complexes produced chiral boranes with excellent enantioselectivity (up to 96% ee). This is the first report of highly enantioselective heteroatom-hydrogen bond insertion reactions of metal carbenes generated in situ from alkynes. The chiral products of the reaction could be easily transformed to widely used borates and diaryl methanol compounds without loss of optical purity, which demonstrates its potential utility in organic synthesis. A kinetics study indicated that the Cu-catalyzed B-H bond insertion reaction is first order with respect to the catalyst and the alkyne and zero order with respect to the borane adduct, and no kinetic isotopic effect was observed in the reaction of the adduct. These results, along with density functional theory calculations, suggest that the formation of the Cu carbene is the rate-limiting step and that the B-H bond insertion is a fast, concerted process.

A bioinspired enantioselective synthesis of crinine-type alkaloids has been developed by iridium-catalyzed asymmetric hydrogenation of racemic cycloenones. The method features a biomimetic stereodivergent resolution of the substrates bearing a remote arylated quaternary stereocenter. Using this protocol, 24 crinine-type alkaloids and 8 analogues were synthesized in a concise and rapid way with high yield and high enantioselectivity.

A highly efficient asymmetric Michael addition of thiols to exocyclic enones was achieved by using chiral spiro phosphoramide catalysts. The precisely chiral control in the protonation of the enol intermediate ensured high enantioselectivity. The reaction features high activity (yields up to 99%, turnover numbers up to 8400) and high enantioselectivity (up to 97% ee) with a broad substrate scope, and it has the potential for wide application in the synthesis of chiral sulfides.

An iterative protocol was developed for highly diastereo- and enantioselective construction of high-order 1,3-polyols via iridium-catalyzed asymmetric hydrogenation of β-alkyl-β-keto esters. The protocol involves four operations-asymmetric hydrogenation, hydroxy protection, ester hydrolysis, and C-acylation-and the catalyst loading can be as low as 0.005 mol %. The configurations of all stereogenic centers of 1,3-polyols are controlled by the catalyst. By the use of this protocol, a formal total synthesis of the polyketide cyanolide A was achieved with high diastereoselectivity and enantioselectivity.

The first highly enantioselective intramolecular N−H bond insertion was realized by using copper catalysts modified with chiral spirobisoxazoline ligands, which provides a novel strategy for the synthesis of chiral 2-carboxytetrahydroquinolines. This reaction features fast reaction rate, high yield, high enantioselectivity, and mild reaction conditions.

A new strategy featuring an iridium-catalyzed asymmetric hydrogenation of a racemic ketone via dynamic kinetic resolution to generate a cyclopentanol with three contiguous stereocenters and a SmI2-promoted pinacol coupling to install the six-membered ring with correct stereochemistry has been described for the enantioselective total synthesis of (-)-hamigeran B (19 steps, 10.6% overall yield) and (-)-4-bromohamigeran B (19 steps, 12.3% overall yield).

An enantioselective synthesis of pharmaceutically important spirobarbiturates has been achieved via spirocyclic chiral phosphine-catalyzed asymmetric [4 + 2] annulation of barbiturate-derived alkenes with allenoates. With the use of this tool, various spirobarbiturate-cyclohexenes are obtained in good to excellent yields with excellent diastereo- and enantioselectivities. A wide range of α-substituted allenoates and barbiturate-derived alkenes were tolerated.

A divergent enantioselective approach to hapalindole-type alkaloids featuring a ruthenium-catalyzed asymmetric hydrogenation and a switchable sequence of methylation and acetylation/aldol reaction is described., A divergent enantioselective approach to hapalindole-type alkaloids is described. The route features a ruthenium-catalyzed asymmetric hydrogenation of a ketone via DKR to construct the chiral trans-1-indolyl-2-isopropenylcyclohexane skeleton and a switchable sequence of methylation and acetylation/aldol reaction to access a chiral quaternary stereocenter. (+)-Hapalindole Q (1, 13 steps, 5.9% overall yield), (–)-12-epi-hapalindole Q isonitrile (2, 15 steps, 5.5% overall yield), (–)-hapalindole D (3, 14 steps, 2.3% overall yield), and (+)-12-epi-fischerindole U isothiocyanate (4, 14 steps, 3.0% overall yield) were synthesized in 13–15 steps from a commercially available material to demonstrate the application of this approach.

A new highly enantioselective route to α-alkenyl α-amino acid derivatives, which are important naturally occurring compounds with attractive bioactivity and synthetic utility, was developed using a N–H insertion reaction of vinyldiazoacetates and tert-butyl carbamate cooperatively catalyzed by achiral dirhodium(II) carboxylates and chiral spiro phosphoric acids under mild, neutral conditions. This reaction has a broad substrate scope, a fast reaction rate (turnover frequency > 6000 h−1), a high yield (61–99%), and excellent enantioselectivity (83–98% ee). The chiral spiro phosphoric acid, which is proposed to realize the enantioselectivity of the insertion reaction by promoting the proton transfer of a ylide intermediate by acting as a chiral proton shuttle catalyst, can suppress several usual side reactions of vinyldiazoacetates and broaden the applications of these versatile carbene precursors in organic synthesis. To our knowledge, it is the first highly enantioselective carbene insertion reaction of vinyldiazoacetates with heteroatom–hydrogen bonds in which the heteroatom has lone-pair electrons.

An iridium complex with a newly prepared chiral spiro amino-phosphine ligand efficiently catalyzed the hydrogenation of both β-aryl-β-methyl-nitroalkenes and β-alkyl-β-methyl-nitroalkenes to the corresponding saturated nitroalkanes, which represents the first report of a chiral catalyst that exhibits high enantioselectivity for the challenging hydrogenation of β,β-dialkyl-nitroalkenes.

We developed a highly regioselective addition of 1,3-dienes with simple ketones by nickel-hydride catalyst bearing DTBM-SegPhos ligand. A wide range of aromatic and aliphatic ketones directly coupled with 1,3-dienes, providing synthetically useful γ,δ-unsaturated ketones in high yield and regioselectivity. The asymmetric version of the reaction was also realized in high enantioselectivity by using novel chiral ligand DTBM-HO-BIPHEP. The utility of this hydroalkylation was demonstrated by facile product modification and enantioselective synthesis of ( R)-flobufen.

Although transition-metal-catalyzed B-H bond insertion of carbenes into stable borane adducts has emerged as a promising method for organoborane synthesis, all the diazo compounds used to date as carbene precursors have had an electron-withdrawing group to stabilize them. Herein, we report a protocol for rhodium-catalyzed B-H bond insertion reactions of unstabilized diazo compounds generated in situ from tosylhydrazones. In addition, by using chiral dirhodium catalysts, we also achieved an asymmetric version of the reaction with good to excellent enantioselectivities (up to 98:2 e.r.). This is the first enantioselective heteroatom-hydrogen bond insertion reaction to use unstabilized diazo compounds as carbene precursors. The protocol exhibited good functional group tolerance and could be carried out on a gram scale. It also enabled one-pot transformation of a carbonyl group to a boryl group enantioselectively. The B-H bond insertion products could be easily transformed into chiral alcohols and other widely used organoboron reagents with enantiomeric fidelity.

1,1′-Spirobiindane has been one type of privileged skeleton for chiral ligand design, and 1,1′-spirobiindane-based chiral ligands have demonstrated outstanding performance in various asymmetric catalysis. However, the access to enantiopure spirobiindane is quite tedious, which obstructs its practical application. In the present article, a facile enantioselective synthesis of cyclohexyl-fused chiral spirobiindanes has been accomplished, in high yields and excellent stereoselectivities (up to >99% ee), via a sequence of Ir-catalyzed asymmetric hydrogenation of α,α′-bis(arylidene)ketones and TiCl4 promoted asymmetric spiroannulation of the hydrogenated chiral ketones. The protocol can be performed in one pot and is readily scalable, and has been utilized in a 25 g scale asymmetric synthesis of cyclohexyl-fused spirobiindanediol (1S,2S,2′S)-5, in >99% ee and 67% overall yield for four steps without chromatographic purification. Facile derivations of (1S,2S,2′S)-5 provided straightforward access to chiral mono...

A highly enantioselective nickel-catalyzed intramolecular hydroalkenylation of N- or O-tethered 1,6-dienes was developed by using monodentate chiral spiro phosphoramidite ligands. The reaction provides an efficient and straightforward method for preparing very useful six-membered N- and O-heterocycles with high regioselectivity as well as excellent stereoselectivity from easily accessible starting materials under mild reaction conditions. The chiral spiro nickel catalyst developed in this study represents one of the few catalysts for highly enantioselective cyclization of unconjugated dienes.

The chiral tridentate spiro P-N-S ligands (SpiroSAP) were developed, and their iridium complexes were prepared. Introduction of a 1,3-dithiane moiety into the ligand resulted in a highly efficient chiral iridium catalyst for asymmetric hydrogenation of β-alkyl-β-ketoesters, producing chiral β-alkyl-β-hydroxyesters with excellent enantioselectivities (95-99.9% ee) and turnover numbers of up to 355,000.

The first regioselective catalytic asymmetric [3 + 2] cycloaddition of benzofuranone-derived olefins with allenoates and substituted allenoates has been developed in the presence of (R)-SITCP, affording different functionalized 3-spirocyclopentene benzofuran-2-ones in good yields with high enantioselectivities under mild conditions. The substrate scope has also been examined. The regioselective outcomes for this phosphine-catalyzed [3 + 2] cycloaddition reaction can be rationalized using DFT calculations.

While the phosphine catalysis is a powerful tool for the construction of N-heterocycles, the phosphine-catalyzed annulations toward lactam motif are still extremely scarce. Here, we report the asymmetric (3 + 2) annulations of δ-acetoxy allenoates with β-carbonyl amides by using the (R)-SITCP catalyst. The δC and γC of allenoate respectively engage in annulation with the αC and N of the amide, forging a γ-lactam with good to excellent stereoselectivity.

A highly efficient iridium-catalyzed asymmetric hydrogenation of tetrasubstituted cyclic enones has been developed for the enantioselective synthesis of chiral cycloalkanols with three contiguous stereocenters. The C═O and C═C bonds of the enone substrates were hydrogenated sequentially in one pot with excellent enantioselectivity (92 to >99% ee) and diastereoselectivity (dr 95:5 to >99:1). The reaction provided a practical approach to all of the stereoisomers of the antiulcer drug rosaprostol.

We report the first intramolecular enantioselective cyclopropanation of indoles, which was accomplished in good to high yield (up to 94%) with excellent enantioselectivity (up to >99.9% ee) by using copper or iron complexes of chiral spiro bisoxazolines as catalysts. This reaction is a straightforward, efficient method for constructing polycyclic compounds with an all-carbon quaternary stereogenic center at the 3-position of the indole skeleton, a core structure shared by numerous natural products and bioactive compounds.

An iron-catalyzed asymmetric intramolecular cyclopropanation was realized in high yields and excellent enantioselectivity (up to 97 % ee) by using the iron complexes of chiral spiro-bisoxazoline ligands as catalysts. The superiority of iron catalysts exhibited in this reaction demonstrated the potential abilities of this sustainable metal in asymmetric carbenoid transformation reactions.

A highly efficient iridium-catalyzed asymmetric hydrogenation of α-amino ketones for the synthesis of chiral 1,2-amino alcohols is described. With chiral spiro iridium catalyst Ir-( R )- 1c , a series of α-amino ketones were hydrogenated to chiral β-amino alcohols in excellent enantioselectivities (up to 99.9% ee) with TON up to 100 000. In addition, with this highly efficient method the chiral drugs ( R )-clorpenaline and ( R )-phenylephrine were prepared in very high efficiency.

A highly enantioselective NH insertion reaction of α-diazoketones was developed by using cooperative catalysis by dirhodium(II) carboxylates and chiral spiro phosphoric acids. The insertion reaction provides a new access route to diverse chiral α-aminoketones, which are versatile building blocks in organic synthesis, with fast reaction rates, good yields and high enantioselectivity under mild and neutral conditions.

A new efficient and highly enantioselective direct asymmetric hydrogenation of α-keto acids employing the Ir/SpiroPAP catalyst under mild reaction conditions has been developed. This method might be feasible for the preparation of a series of chiral α-hydroxy acids on a large scale.

The first highly enantioselective intramolecular N−H bond insertion was realized by using copper catalysts modified with chiral spirobisoxazoline ligands, which provides a novel strategy for the synthesis of chiral 2-carboxytetrahydroquinolines. This reaction features fast reaction rate, high yield, high enantioselectivity, and mild reaction conditions.

The method is extended to the preparation of (VI), the key intermediate for the synthesis of (+)-chelidonine (VII).

A highly efficient asymmetric hydrogenation of α,β-unsaturated carboxylic acids with tetrasubstituted olefin catalyzed by chiral spiro iridium complexes has been developed for the preparation of chiral α-substituted carboxylic acids in excellent enantioselectivities (up to 99% ee).

An efficient catalytic asymmetric hydrogenation of racemic α-arylcyclohexanones with an ethylene ketal group at the 5-position of the cyclohexane ring via dynamic kinetic resolution has been developed, giving chiral α-arylcyclohexanols with two contiguous stereocenters with up to 99% ee and >99:1 cis/trans-selectivity. Using this highly efficient asymmetric hydrogenation reaction as a key step, (−)-α-lycorane was synthesized in 19.6% overall yield over 13 steps from commercially available starting material.

A copper-catalyzed asymmetric allylic oxidation of acyclic olefins has been developed. By using the complexes of copper and chiral spiro bisoxazoline ligands as catalysts, the oxidation of various acyclic olefins was accomplished with excellent regioselectivity (>20:1 in most cases) and up to 67% ee under mild reaction conditions, which represents one of the best results for the enantioselective allylic oxidation of acyclic olefins.