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Three new dihydrocarbyl LPtIVMe(Y) complexes (6–8; Y = Cl, I, OCH2CF3) supported by the sulfonated CNN pincer ligand L have been prepared and characterized. The reaction of these complexes with a number of nucleophiles (H2O, CF3CO2–, Me2SO, PhNMe2) resulting in the formation of corresponding C–X coupled products CH3–X has been studied in 2,2,2-trifluoroethanol (TFE) and DMSO. In TFE or DMSO solutions at 22 °C, in the presence of PhNMe2, a quantitative formation of a C–N coupled product, PhNMe3+, was observed for 6–8, with the reactivity decreasing in the order 6 > 7 > 8. The use of NaO2CCF3 in TFE solutions was less efficient, leading to the production of MeO2CCF3 in 60% yield after 22 h at 70 °C. In DMSO the C–O coupling was high yielding when aqueous trifluoroacetic acid was used to produce methanol (87% after 3 h at 80 °C) or when NaO2CCF3 was used to form MeO2CCF3 (80% after 1.5 h at 80 °C), with Me3SO+ being a minor byproduct. The kinetics study of the reaction between 6–8 and PhNMe2 in TFE has revea...

In order to reduce the shock and vibration caused by torque disturbance of the gearbox in vehicles equipped with automatic transmission in the process of in situ shift, a novel semi-active hydraulic damping strut is introduced in the powertrain mounting system. The dynamic response evaluation indexes of vehicle in situ shift are put forward, and a 13-degree of freedom vehicle dynamic model including the semi-active hydraulic damping strut is established. The optimized dynamic characteristic parameters are acquired according to the principle of sharing force and the 13-degree of freedom vehicle dynamic model. The dynamic response evaluation indexes with and without the semi-active hydraulic damping strut are calculated using the 13-degree of freedom vehicle dynamic model in the process of in situ shift, and the calculation results show that the vibration of a vehicle can be reduced by the introduction of a semi-active hydraulic damping strut. Experiments are carried out to analyze the vibration response of the vehicle with and without a semi-active hydraulic damping strut, and the results show that the shock and vibration of the vehicle are reduced by introducing the semi-active hydraulic damping strut. The theoretical calculation values of active-side acceleration of the engine mount and torque strut are consistent with the experimental values, which show that the 13-degree of freedom vehicle dynamic model is reasonable.

To reduce the vibration and shock of powertrain in the process of engine key on/off and vehicle in situ shift, a novel semi-active hydraulic damping strut is developed. The purpose of this paper is to study and discuss the dynamic stiffness model of the semi-active hydraulic damping strut. In this study, the dynamic characteristics of semi-active hydraulic damping strut were analyzed based on MTS 831 test rig first. Then, the dynamic stiffness model of semi-active hydraulic damping strut was established based on 2 degrees of freedom vibration system. In this research, a linear, fractional derivative and friction model was used to represent the nonlinear rubber bushing characteristic; the Maxwell model was used to describe the semi-active hydraulic damping strut body model; and the parameters of rubber bushing and semi-active hydraulic damping strut body were identified. The dynamic stiffness values were calculated with solenoid valve energized and not energized at amplitudes of 1 mm and 4 mm, which were consistent with experimental results in low-frequency range. Furthermore, the simplified dynamic stiffness model of the semi-active hydraulic damping strut was discussed, which showed that bushing can be ignored in low-frequency range. Then, the influence of equivalent spring stiffness, damping constant, and rubber bushing stiffness on the stiffness and damping capacity of the semi-active hydraulic damping strut were analyzed. Finally, the prototype of the semi-active hydraulic damping strut was developed and designed based on the vehicle in situ shift and engine key on/off situations, and experiments of the vehicle with and without semi-active hydraulic damping strut were carried out to verify its function.

This report details the first organocatalytic method for nitrenoid transfer and its application to intermolecular, site-selective C(sp3)–H amination. The method utilizes a trifluoromethyl iminium salt as the catalyst, iminoiodinanes as the nitrogen source, and substrate as the limiting reagent. Activated, benzylic, and aliphatic substrates can all be selectively functionalized in yields up to 87%. A mechanistic proposal for the observed reactivity supported by experimental evidence invokes the intermediacy of a diaziridinium salt or related organic nitrenoid, species that have not been previously explored for the purpose of C–H amination. Finally, examples of late-stage functionalization of complex molecules highlight the selectivity and potential utility of this catalytic method in synthesis.

Two novel sulfonated CNN-pincer ligands 1b and 1c and the corresponding chloro and aqua complexes K[CNNLPtCl] and CNNLPt(H2O), 3b–3c and 2b–2c, were prepared and fully characterized including single crystal X-ray diffraction. Along with the previously described complexes 2a and 3a, the derivatives of a CNN pincer ligand 1a, these complexes form a family of structurally similar compounds where the pincer core rigidity increases in the series 2a (3a)

Five dynamic response evaluation indices from the viewpoint of the powertrain mount system and the vehicle system during the vehicle key on/off periods (i.e. the engine start and stop) are proposed. By analysis using different methods to minimize the powertrain vibration, it was found that an increase in the mount system damping can decrease the vehicle key on and key off vibration. For this reason, in this paper a semi-active hydraulic damping strut is designed and made which can provide high damping for a mount system when the vehicle key on/off but switches to lower damping to isolate high-frequency vibrations under normal conditions. The calculated longitudinal acceleration of the powertrain, the jerk of the powertrain, the dynamic force of the mount and the vibration dose value for a vehicle with the semi-active hydraulic damping strut and without the semi-active hydraulic damping strut are compared on the basis of the excitation force identified for the powertrain using a 13-degree-of-freedom vehicle model. Experiments were carried out, and the results show that the use of the semi-active hydraulic damping strut can decrease the engine start and stop vibrations to a large extent. Finally, the experimental results are compared with the calculated values from the 13-degree-of-freedom vehicle model.

The first examples of catalysis of aliphatic C-H hydroxylation by an iminium salt are presented. The method allows the selective organocatalytic hydroxylation of unactivated 3° C-H bonds at room temperature using hydrogen peroxide as the terminal oxidant. Hydroxylation of an unactivated 2° C-H bond is also demonstrated. Furthermore, improved functional group compatibility over other catalytic methods is reported in the form of selectivity for aliphatic C-H hydroxylation over alcohol oxidation. On the basis of initial mechanistic studies, an oxaziridinium species is proposed as the active oxidant.

We report platinum catalysts for the efficient aerobic oxidation of olefins to form epoxides and/or derived glycol monoethers. The catalysts—diaqua and dichloro PtII complexes supported by the ligand di(2-pyridine)methanesulfonate (dpms)—are most active when they are covalently tethered to mesoporous silica nanoparticles (MSNs). Supporting the molecular Pt complexes on the MSNs prevents bimolecular catalyst deactivation. Using this strategy, >40 000 turnovers are achieved for the aerobic oxidation of norbornene in 2,2,2-trifluoroethanol. The position of the tether and the nature of other ligands in the metal coordination sphere (aqua, hydroxo, or chloro) are shown to affect the catalyst activity. The new MSN-supported Pt materials were characterized by nuclear magnetic resonance (NMR) spectroscopy, nitrogen physisorption, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA).

Catalytic oxidative C–H acetoxylation of 8-methylquinoline as a model substrate with O2 as oxidant was performed using palladium(II) carboxylate catalysts derived from four different pyridinecarboxylic acids able to form palladium(II) chelates of different size. A comparison of the rates of the substrate C–H activation and the O2 activation steps shows that the C–H activation step is rate-limiting, whereas the O2 activation occurs at a much faster rate already at 20 °C. The chelate ring size and the chelate ring strain of the catalytically active species are proposed to be the key factors affecting the rate of the C–H activation.

Unsymmetrical hybrid chiral phosphine-aminophosphine ligand derived from 1,2,3,4-tetrahydro-1-naphthylamine has been found to be highly efficient in the Ir-catalyzed asymmetric hydrogenation of various 3-aryl-2H-1,4-benzoxazines, providing good enantioselectivities (up to 95% ee) and high catalytic activity (S/C up to 5000).

A new family of chiral ferrocenyl p,s-ligands incorporating an indole ring at the alpha-ferrocenylmethyl position has been prepared via a friedel-crafts alkylation reaction of (r-c,s-fc)-ppfa with a variety of 2-indole thioethers. these newly developed ferrocenyl p,s-ligands proved to be efficient in the agoac-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with various dipolarophiles, giving cycloadducts with high diastereoselectivities and enantioselectivities (up to 99% ee). (c) 2012 elsevier ltd. all rights reserved.

The commercially available ferrocene-based diphosphine ligand (Sc,SFc)-TaniaPhos was found to be highly effective in the Rh-catalyzed asymmetric hydrogenation of 3-aryl-2-(phosphonomethyl)propenates. Excellent enantioselectivity (90–98% ee) and high catalytic activity (S/C up to 1000) have been achieved, which represents the best results reported so far.

An enantioselective synthesis of chiral alkylphosphonates bearing a beta-stereogenic center, based on the Rh-catalyzed asymmetric hydrogenation of corresponding beta-substituted beta,gamma-unsaturated phosphonates with a ferrocene-based monophosphoramidite ligand under the mild hydrogenation conditions, was developed, in which an ee value of up to 98% was obtained.

The first Rh-catalyzed enantioselective hydrogenation of dimethyl 2-methyleneglutarate and its derivatives has been reported. For the hydrogenation of dimethyl 2-methyleneglutarate with a chiral ferrocene-based monodentate phosphoramidite ligand (FAPhos), good enantioselectivity (over 90% ee) with full conversions was achieved. In contrast, the hydrogenation of substrates bearing an aryl substituent at a methylene moiety proved to be more difficult, in which the best enantioselectivity of up to 81% ee was obtained by the use of a P-stereogenic BoPhoz-type ligand.

A series of chiral ferrocene-based phosphine–phosphoramidite ligands (PPFAPhos) have been employed in the Ag(I)-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with dimethyl maleate. The results showed that the ligand with a stereogenic P-center in the phosphino moiety displayed the best diastereo- and enantioselectivities, in which up to 99% enantiomeric excesses and 99/1 endo/exo selectivities have been achieved.

Methyl 3-hydroxy-2-methylpropionate, known as the Roche ester, was prepared with high enantioselectivity (up to 96.7% ee) via the Rh-catalyzed asymmetric hydrogenation of methyl 2-hydroxymethylacrylate with a chiral 1,2,3,4-tetrahydro-1-naphthylamine-derived phosphine-phosphoramidite ligand (THNAPhos 5a) even at a low catalyst loading (0.1 mol %). An investigation on the substrate scope revealed that the ester group present in the substrate has a significant effect on the enantioselectivity, and the substrate with the bulkier ester group tended to give lower enantioselectivity.

A series of new chiral phosphine-aminophosphine ligands [(R)-HW-Phos] has been prepared from (R)-l.,2,3,4-tetrahydro-1-naphthylamine through a two-step procedure, and successfully applied in the rhodium-catalyzed asymmetric hydrogenation of various functionalized olefins such as alpha-enol ester phosphonates, alpha-enamido phosphonates, (Z)-beta-(acylamino)acrylates and so on. Excellent enantioselectivities have been achieved in the hydrogenation of most substrates tested, demonstrating the high potential of these newly developed phosphine-aminophosphine ligands in asymmetric catalysis. The present research also discloses that these newly developed phosphine-aminophosphine ligands are more efficient than that derived from (S)-1-phenyl ethyl amine, suggesting that the increased rigidity conferred by a cyclohexyl fragment in these phosphine-aminophosphine ligands has a positive effect in the asymmetric induction.

A series of chiral beta-substituted alkane-phosphonates was synthesized in high enantioselectivities via the first rhodium-catalyzed asymmetric hydrogenation of the corresponding beta-substituted-alpha,beta-unsaturated phosphonates using a ferrocene-derived rnonophosphoramidite ligand, with which up to 99.5% ee have been achieved for the hydrogenation of (E)-substrates and 98.0% ee for (Z)-substrates.

A new chiral phosphine-phosphoramidite ligand (S)-HY-Phos 1 has been prepared from 1-naphthylamine via a two-step transformation, and successfully applied in the Rh-catalyzed asymmetric hydrogenation of various functionalized olefins, including α-(acetamido)cinnamates, enamides and α-enol ester phosphonates, in which up to 98% ee, 99% ee and 99% ee were achieved, respectively.

We have recently reported a new chiral 1,2,3,4-tetrahydro-1-naphthylamine-derived phosphine-phosphoramidite ligand, (R-c,R-a)-THNAPhos, that is highly efficient in the rhodium-catalyzed asymmetric hydrogenation of a broad range of alpha-enol ester phosphonates. To further demonstrate the utility of THNAPhos in asymmetric hydrogenation, in this paper, we describe its new application in the asymmetric hydrogenation of alpha-dehydroamino acid esters, enamides, dimethyl itaconate and alpha-enamido phosphonates. The results disclosed that the Rh/(R-c,R-a)-THNAPhos complex is highly effective for the enantioselective hydrogenation of these kinds of functionalized C=C olefins, affording the corresponding hydrogenation product in excellent enantioselectivities (normally over 99% ee).

A new class of unsymmetrical hybrid phosphine--aminophosphine ligands has been prepared from commercially available, inexpensive (S)-1-phenylethylamine through a concise synthetic procedure. These ligands are not very sensitive to air and moisture, and displayed good enantioselectivities in the Rh-catalyzed asymmetric hydrogenation of various dimethyl alpha-benzoyloxyethenephosphonates bearing beta-aryl, beta-alkyl, and beta-alkoxy substituents and N-benzyloxycarbonyl alpha-enamido phosphonates, in which up to 97% ee was obtained. A side-by-side comparison study disclosed that these new phosphine--aminophosphine ligands showed better enantioselectivity than BoPhoz ligands.

A series of ferrocene-based phosphine-triazine ligands were successfully employed in the Pd-catalyzed Suzuki - Miyaura crosscoupling reaction of aryl chlorides with arylboronic acids, with ligand 1b was demonstrated to be the most effective one. Under optimized reaction conditions, the catalytic system displayed a remarkable tolerance towards electron-donating substituents and electron-withdrawing substituents. (c) 2007 Published by Elsevier Ltd.

Optically active a-hydroxy phosphonic acid derivatives are widely used as enzyme inhibitors, antibacterial agents, antiviral agents, antibiotics, anticancer agents, and pesticides, as well as useful building blocks for the synthesis of many other important a-functionalized optically active phosphonates. Therefore, an enantioselective synthesis of these compounds is highly desirable. Asymmetric catalysis has provided several novel solutions for the synthesis of chiral a-hydroxy phosphonic acid derivatives, including asymmetric reduction of ketophosphonates and phosphonylation of carbonyl compounds. For its inherent efficiency and atom economy, much effort in the past few years has been directed toward the development of an asymmetric hydrogenation of a-enol esters of phosphonate substrates. By this means, b-alkyl-substituted a-acyloxy phosphonates were hydrogenated with good enantioselectivities by using Rh catalysts bearing DuPHOS (1,2bis((2R,5R)-2,5-dialkylphospholano)benzene), BisP* ((S,S)1,2-bis(alkylmethylphosphino)ethane), MiniPHOS (R,Rbis(alkylmethylphosphino)methane),and phosphine–phosphite ligands. However, catalyst performance for b-aryland b-alkoxy-substituted substrates was less than satisfactory, as moderate enantioselectivities or low conversions were observed in most cases. Recently, Pizzano and co-workers reported that the use of a phosphine–phosphite/Rh catalyst could give rise to an ee value of up to 92% in the asymmetric hydrogenation of baryl-substituted substrates, although only the b-phenyl-substituted substrate afforded an ee value over 90% under full conversion. As for the hydrogenation of b-alkoxy-substituted substrates, there is only one report on the asymmetric hydrogenation of this class of substrates, in which 87% ee was obtained. Therefore, the highly enantioselective synthesis of a-hydroxy phosphonate derivatives by asymmetric hydrogenation of a-enol ester phosphonates, especially those bearing b-aryl or b-alkoxy substituents, is still a significant challenge for organic chemists. Herein, we report a new chiral phosphine–phosphoramidite ligand derived from (Rc)-1,2,3,4tetrahydro-1-naphthylamine (Rc= central chirality), which promoted unprecedented enantioselectivities (up to 99.9% ee) in Rh-catalyzed asymmetric hydrogenation across a broad range of substrates bearing b-aryl, b-alkoxy, and balkyl substituents. Ligand design has played a pivotal role in the development of efficient metal-catalyzed asymmetric reactions. Although a large number of bidentate phosphorus ligands with C2 symmetry or two closely related binding sites have been prepared and examined for asymmetric hydrogenation, significantly fewer unsymmetrical hybrid bidentate phosphorus ligands were disclosed. We and others have recently revealed that chiral phosphine–phosphoramidite ligands are highly efficient for the asymmetric hydrogenation of various functionalized olefins, including aand b-dehydroamino acid esters, itaconate, and enamides. In our ongoing efforts toward the development of new and practical chiral ligands for use in the hydrogenation of challenging substrates, we designed a class of rigid chiral phosphine–phosphoramidite ligands with a 1,2,3,4-tetrahydronaphthalene backbone. The phosphine–phosphoramidite ligands 1 can be readily prepared from optically pure (Rc)-1,2,3,4-tetrahydro-1-naphthylamine ((Rc)-2) through a concise synthetic procedure (Scheme 1). The initial step involves functionalization of

A series of novel chiral phosphine–imine ligands have been prepared by a two-step transformation from chiral α-phenylethylamine. The resulting chiral ligands were found to be effective for the palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenylprop-2-en-1-yl pivalate with dimethyl malonate, in which up to 94% ee and 99% conversions were obtained. The results demonstrate that the chirality resided on the chelate ring of P–Pd–N complex is more effective for the transfer of the stereochemical information by comparison with the result obtained by Hashimoto and coworkers’ phosphine–imine ligand, in which the chirality lay in the outside of P–Pd–N chelate ring. The effect of solvent, base and substitutent in phosphine–imine ligand on this catalytic reaction is also described.

A series of chiral alkylphosphonates bearing β-stereogenic center were synthesized in good enantioselectivities (up to 95% ee) via the CuH-catalyzed asymmetric conjugate reduction of β-substituted α,β-unsaturated phosphonates under optimal conditions using Cu(OAc)2·H2O as the copper source, (R)-SEGPHOS as the ligand, PMHS as the siloxane, and t-BuOH as the additive.

An enantioselective synthesis of optically active 1-aryl or 1-alkyl substituted ethylphosphonates, based on the first Rh-catalyzed asymmetric hydrogenation of corresponding alpha,beta-unsaturated precursors with a P-stereogenic BoPhoz-type ligand under the mild condition, was developed, in which a wide range of 1-aryl or 1-alkyl substituted ethylphosphonates were achieved in up to 98% ee.

The title compound, [Co(C12H8N2)(H2O)4]2(C10H2O8), consists of discrete tetra­aqua­(1,10-phenanthroline)cobalt(II) cations and 1,2,4,5-benzene­tetra­carboxyl­ate anions. The CoII atom is octa­hedrally coordinated by two N atoms of the 1,10-phenanthroline ligand and four O atoms of water mol­ecules. The anion lies on an inversion centre. A two-dimensional hydrogen-bonding network is formed by O atoms of benzene­tetra­carboxyl­ate and the coordinated water mol­ecules.

A new one-dimensional coordination polymer, catena-poly­[[aqua­(nitrato-κ2O,O′)copper(II)]-μ-pyrazine-2-carboxyl­ato- κ3N1,O:N4], [Cu(C5H3N2O2)(NO3)(H2O)]n, has been synthesized and characterized. The coordination environment of the copper(II) ion is distorted octahedral, arising from an N,O-bidentate 2-pyrazine­carboxyl­ate ligand, an N atom from a symmetry-related 2-pyrazine­carboxyl­ate ligand, a bidentate nitrate group and a water mol­ecule. The chains interact by way of O—H⋯O hydrogen bonds and C—H⋯O interactions.

A new family of chiral ferrocenyl p,s-ligands incorporating an indole ring at the alpha-ferrocenylmethyl position has been prepared via a friedel-crafts alkylation reaction of (r-c,s-fc)-ppfa with a variety of 2-indole thioethers. these newly developed ferrocenyl p,s-ligands proved to be efficient in the agoac-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with various dipolarophiles, giving cycloadducts with high diastereoselectivities and enantioselectivities (up to 99% ee). (c) 2012 elsevier ltd. all rights reserved.

The commercially available ferrocene-chiral diphosphine ligand FDP is highly effective for the hydrogenation of 3-arylpropenoates to give the corresponding propanoates with up to 98% e.e.

The cyclic enones (I) and (VI) react with a variety of aromatic azomethine ylides under conditions A) to give exclusively endo-cycloadducts with excellent enantioselectivities.

A new family of chiral ferrocenyl p,s-ligands has been developed and successfully applied in a highly endo-selective catalytic asymmetric cycloaddltion of azomethine ylides with various enones, including cyclic and acyclic alpha-enones. for cyclic alpha-enones, a [cu(ch3cn)(4)]clo4/(r-c,s-fc)-2f complex catalyzed the cycloaddition to give the sole endo-cycloadducts in perfect enantioselectivities (normally 99% ee), while an agoac/(r-c,s-fc)-2f catalytic system exhibited good endo/exo selectivities (endo/exo = 91/9 to 96/4) and high enantiocontrol (up to 98% ee) for acyclic alpha-enones.

An enantioselective synthesis of chiral alkylphosphonates bearing a β-stereogenic center, based on the Rh-catalyzed asymmetric hydrogenation of corresponding β-substituted β,γ-unsaturated phosphonates with a ferrocene-based monophosphoramidite ligand under the mild hydrogenation conditions, was developed, in which an ee value of up to 98% was obtained.

A series of chiral alkylphosphonates bearing β-stereogenic center were synthesized in good enantioselectivities (up to 95% ee) via the CuH-catalyzed asymmetric conjugate reduction of β-substituted α,β-unsaturated phosphonates under optimal conditions using Cu(OAc)2·H2O as the copper source, (R)-SEGPHOS as the ligand, PMHS as the siloxane, and t-BuOH as the additive.

A new class of chiral ferrocenyl diphosphine ligands with an imidazole ring, (R(c), S(Fc))-ImiFerroPhos, has been prepared from acylferrocenes through a five-step transformation and successfully applied in the Rh-catalyzed asymmetric hydrogenation of various 3-aryl-substituted 2-phosphonomethylpropenoates, in which a series of chiral 3-phosphono-2-arylmethylpropanoic acid derivatives were achieved in ee values of up to 98%.

An enantioselective synthesis of optically active 1-aryl or 1-alkyl substituted ethylphosphonates, based on the first Rh-catalyzed asymmetric hydrogenation of corresponding α,β-unsaturated precursors with a P-stereogenic BoPhoz-type ligand under the mild condition, was developed, in which a wide range of 1-aryl or 1-alkyl substituted ethylphosphonates were achieved in up to 98% ee.

A series of chiral ferrocene-based phosphine–phosphoramidite ligands (PPFAPhos) have been employed in the Ag(I)-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with dimethyl maleate. The results showed that the ligand with a stereogenic P-center in the phosphino moiety displayed the best diastereo- and enantioselectivities, in which up to 99% enantiomeric excesses and 99/1 endo/exo selectivities have been achieved.

Methyl 3-hydroxy-2-methylpropionate, known as the Roche ester, was prepared with high enantioselectivity (up to 96.7% ee) via the Rh-catalyzed asymmetric hydrogenation of methyl 2-hydroxymethylacrylate with a chiral 1,2,3,4-tetrahydro-1-naphthylamine-derived phosphine-phosphoramidite ligand (THNAPhos 5a) even at a low catalyst loading (0.1 mol %). An investigation on the substrate scope revealed that the ester group present in the substrate has a significant effect on the enantioselectivity, and the substrate with the bulkier ester group tended to give lower enantioselectivity.

A new class of chiral ferrocenyl diphosphine ligands with an imidazole ring, (R(c), S(Fc))-ImiFerroPhos, has been prepared from acylferrocenes through a five-step transformation and successfully applied in the Rh-catalyzed asymmetric hydrogenation of various 3-aryl-substituted 2-phosphonomethylpropenoates, in which a series of chiral 3-phosphono-2-arylmethylpropanoic acid derivatives were achieved in ee values of up to 98%.

A series of new chiral phosphine-aminophosphine ligands [(R)-HW-Phos] has been prepared from (R)-l.,2,3,4-tetrahydro-1-naphthylamine through a two-step procedure, and successfully applied in the rhodium-catalyzed asymmetric hydrogenation of various functionalized olefins such as alpha-enol ester phosphonates, alpha-enamido phosphonates, (Z)-beta-(acylamino)acrylates and so on. Excellent enantioselectivities have been achieved in the hydrogenation of most substrates tested, demonstrating the high potential of these newly developed phosphine-aminophosphine ligands in asymmetric catalysis. The present research also discloses that these newly developed phosphine-aminophosphine ligands are more efficient than that derived from (S)-1-phenyl ethyl amine, suggesting that the increased rigidity conferred by a cyclohexyl fragment in these phosphine-aminophosphine ligands has a positive effect in the asymmetric induction.

A new chiral phosphine-phosphoramidite ligand (S)-HY-Phos 1 has been prepared from 1-naphthylamine via a two-step transformation, and successfully applied in the Rh-catalyzed asymmetric hydrogenation of various functionalized olefins, including α-(acetamido)cinnamates, enamides and α-enol ester phosphonates, in which up to 98% ee, 99% ee and 99% ee were achieved, respectively.