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Synthesis of new air stable octahedral ruthenium(II) carbonyl complex bearing O, and N-bidentate benzhydrazone ligand is reported. It has been characterized by elemental analysis, spectral methods and single crystal X-ray diffraction method. The new catalyst has been effectively applied to the transfer hydrogenation reaction of various ketones using isopropanol as a solvent and KOH as a base at 82 °C and the maximum conversion is achieved up to 100%.

Herein we describe a new methodology for the asymmetric hydrogenation (AH) of 2-substituted pyridinium salts. An iridium catalyst based on a mixture of a chiral monodentate phosphoramidite and an achiral phosphine was shown to hydrogenate N-benzyl-2-arylpyiridinium bromides to the corresponding N-benzyl-2-arylpiperidines with full conversion and good enantioselectivity. The mechanism of the reaction under optimized conditions was investigated via kinetic measurements and isotopic labeling experiments. Our study suggests that the hydrogenation starts with a 1,4-hydride addition and that the enantiodiscriminating step involves the reduction of an iminium intermediate.

Simple Ir-PHOX-based phosphite-oxazoline catalysts have been successfully applied in the asymmetric hydrogenation of cyclic β-enamides providing better enantioselectivities than previous effective Ru and Rh catalysts. This protocol allows the synthesis of 2-aminotetralines and 3-aminochromanes, key structural units found in many therapeutic agents and biologically active natural products, in high chemical yields and enantioselectivities (ee’s up to 99%). High enantioselectivities have also been achieved in the hydrogenation of cyclic α-enamides.

Rubidium phosphate can be more conveniently obtained by extracting trace Rb+ from the salt lake brine. Rb3PO4 was found to be an excellent heterogeneous catalyst for transfer hydrogenation. Rb3PO4 lost 70% of its active sites after adsorbing water, but the remaining was not affected. The reductions of aldehydes and ketones, when promoted by Rb3PO4, were allowed at room temperature. The activities of substrates at room temperature followed a descending order of 2,6-dichlorobenzaldehyde>4-bromobenzaldehyde>benzaldehyde>acetophenone>anisaldehyde>butanone. A new catalytic cycle postulating a six-membered cyclic transition state for the reductions of aldehydes and ketones was proposed. These results exploited the catalytic usage of Rb3PO4 and worth in industrial application.

Iridium(I) complexes of phosphine-phosphite ligands efficiently catalyze the enantioselective hydrogenation of diverse seven-membered C=N-containing heterocyclic compounds (eleven examples; up to 97% ee). P-OP ligand L3, which incorporates an ortho-diphenyl substituted octahydrobinol phosphite fragment, provided the highest enantioselectivities in the hydrogenation of most of the heterocyclic compounds studied. The observed sense of stereoselection was rationalized by means of DFT calculations.

An efficient trans-selective hydrogenation of alkynes under low hydrogen pressure and low reaction temperatures is reported, applying a commercially available ruthenium hydride complex. The developed reaction conditions, which tolerate a variety of functional groups, are carried out in a two-chamber setup with ex situ generated hydrogen. The reaction setup is highly suitable for deuterium labeling. The trans-selective hydrogenation was extrapolated to a transfer hydrogenation protocol, employing a packed bed immobilized ruthenium hydride catalyst in continuous flow with a retention time of only 10 min.

The transition-metal-catalyzed asymmetric transfer hydrogenation (ATH) and asymmetric hydrogenation (AH) of α- and β-substituted ketone or imine derivatives are efficient methods for accessing chiral alcohols or amines bearing up to three stereogenic centers through a dynamic kinetic resolution (DKR) process. This review provides a summary of recent work in this field, focusing on the development of new catalytic systems and on the extension of these asymmetric reductions to new classes of substrates. 1 Introduction 2 Asymmetric Hydrogenation via Dynamic Kinetic Resolution 2.1 α-Substituted Ketones 2.2. α-Substituted β-Keto Esters and Amides 2.3 α-Substituted β-Keto Phosphonates and Sulfones 2.4 α,α′-Disubstituted Cyclic Ketones 2.5 α,β-Disubstituted Cyclic Ketones 2.6 Imine Derivatives 3 Asymmetric Transfer Hydrogenation via Dynamic Kinetic Resolution 3.1 α-Substituted β-Diketones and Ketones 3.2 α-Substituted β-Keto Esters, Amides and Phosphonates 3.3 β-Substituted α-Keto Esters and Phosphonates 3.4 β-Substituted γ-Keto Esters 3.5 β-Alkoxy Ketones 3.6 Imine Derivatives 4 Conclusion

Deprotonation of HOC(CH2)5CH2C6H4–NMe2-2 (L1H) and HOC(CH2)5C6H4–NMe2-2 (L2H) by equivalent of n-BuLi afforded the pale yellow mixture L1Li or L2Li, which reacted with MgBr2 in different molar ratios to give three novel bidentate N, O-magnesium complexes (1), (2) and (3), respectively. Complexes 1–3 were characterized by 1H and 13C NMR spectroscopy, elemental analyses and single crystal X-ray diffraction techniques. Each of the complexes 1, 2 and 3 was tested for the capability of catalyzing transfer hydrogenation of ketones. Complex 1 exhibited good to excellent catalytic activity, while complexes 2 and 3 showed good activities for the transfer hydrogenation of ketones.

Nanoheterogeneous catalysts based on ruthenium nanoparticles dispersed in crosslinked dendrimer matrixes with a size of polymer particles of 100–500 nm show high activity in the hydrogenation of aromatic compounds under two-phase conditions. The addition of water to the reaction medium exerts a strong promoting effect on the activity of the catalysts: The turnover frequency increases by a factor of 3–90 depending on the substrate. When bimetallic (PdRu) nanoparticles are incorporated into the catalyst composition, the rate of benzene hydrogenation increases while the rate of transformation of substituted benzenes decreases.

For the first time it was established that the catalytic hydrogenation of 2,4,6-trinitrobenzoic acid to 1,3,5-triaminobenzene can proceed via the formation of aromatic hydroxyamines and cyclohexane-1,3,5-trione trioxime. As a result of aqueous-phase hydrogenation of sodium salt of 2,4,6-trinitrobenzoic acid in the presence of 5%Pd/Sibunit catalyst at a temperature of 323 K and pressure of 0.5 MPa, a trioxime in high yield (about 70 %) was obtained. Due to high selectivity to cyclohexane-1,3,5-trione trioxime the catalytic hydrogenation of sodium salt of 2,4,6-trinitrobenzoic acid can be considered as a new method for its synthesis.

Enantiopure heterocyclic architectures containing two or more heteroatoms in the ring system have attracted considerable attraction due to this motif playing a role of great importance in asymmetric synthesis and the pharmaceutical chemistry. This review focused on recent advances in the homogeneous asymmetric hydrogenation of heteroarenes with multiple heteroatoms, which provide an efficient and practical method to structural diverse chiral heterocyclic compounds. 1 Introduction 2 Asymmetric Hydrogenation of Five-Membered-Ring Hetero­arenes 2.1 Imidazoles and Oxazoles 2.2 Pyrazole Derivatives 2.3 Benzisoxazoles 3 Asymmetric Hydrogenation of Six-Membered-Ring Heteroarenes 3.1 Quinoxalines 3.2 Quinazolines 3.3 Pyrimidines 3.4 Pyrazines 4 Asymmetric Hydrogenation of Fused Nitrogen Heteroarenes 4.1 Heteroarenes Containing a Ring-Junction Nitrogen 4.2 Heteroarenes Containing a Fused Pyridine Ring 5 Conclusions and Outlook

Six cationic ruthenium(II) arene thioamide complexes with the general molecular formula [Ru(η6-p-cymene)(PPh3)(L)]+ [where, L = pyridine-2-thioamide and its derivatives] have been successfully synthesized from the reaction of [Ru(η6-p-cymene)Cl2]2 with chelating thioamide ligands and PPh3 in methanol in 1:2 M ratio respectively. All the complexes were isolated as their BPh4−salts and were fully characterized by analytical and spectral (FT-IR, UV-Vis and1H-NMR) methods. The solid-state structure of one of the complexes, [Ru(η6-p-cymene)(PPh3)(L4)]BPh4 (4) (L4 = N-(2, 4, 6-Trimethylphenyl)pyridine-2-thiocarboxamide) has been established by X-ray single crystal diffraction which indicates a pseudo-octahedral (piano-stool) coordination geometry is present in the complex. The ruthenium(II) complexes have been examined for the transfer hydrogenation of various aromatic, heterocycle and cyclic ketones. The formation of ruthenium(II) hydride is confirmed by 1H- NMR and is proposed as the catalytic intermediate in this reaction. Under the optimized conditions, these ruthenium complexes served as excellent catalyst precursors which smoothly reduce the ketones with conversion up to 100%. The influence of other variables on the transfer hydrogenation reaction such as solvent, base, temperature, time, catalyst loading and substrate scope is also reported. Furthermore, the catalyst could be easily recovered and reused at least three times without obvious loss of conversions.

A Noyori-type ruthenium catalyst was immobilized on magnetic platforms consisting of carbon-coated cobalt nanoparticles and different polymers. Both reactivity and enantioselectivity of these catalysts were benchmarked in the asymmetric transfer hydrogenation of acetophenone in an aqueous medium. The best catalyst, having connected the ruthenium catalyst to the nanoparticle by a poly(styrene) matrix, was characterized by infrared (IR) spectroscopy and via a superconducting quantum interference device (SQUID) to determine the saturation magnetization of the magnetic material as well as by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). A variety of aryl methyl ketones could be reduced to their corresponding alcohols with good yields (81–100%) and selectivity (91–99% ee), and catalyst recovery and reuse was evaluated over 10 runs with ruthenium leaching into the product of

CF3 -substituted 1,3-diols were stereoselectively prepared in excellent enantiopurity and high yield from CF3 -substituted diketones by using an ansa-ruthenium(II)-catalyzed asymmetric transfer hydrogenation in formic acid/triethylamine. The intermediate mono-reduced alcohol was also obtained in very high enantiopurity by applying milder reaction conditions. In particular, CF3 C(O)-substituted benzofused cyclic ketones underwent either a single or a double dynamic kinetic resolution during their reduction.

Piano-stool ([(p-cymene)Ru(thz)Cl], 2) and six-coordinated ([Ru(thz)2(PPh3)2], 3) ruthenium complexes derived from 2-phenylthiazoline-4-carboxylic acid (Hthz, 1) were synthesized for the first time, and fully characterized using conventional methods. Also, the molecular structure of complex 3 was determined using X-ray analysis. These complexes were evaluated as catalysts for transfer hydrogenation of carbonyl compounds in the presence of isopropyl alcohol and KOtBu. Complex 2 was found to be more active than 3 in transfer hydrogenation. Copyright © 2016 John Wiley & Sons, Ltd.

A highly enantioselective hydrogenation of heteroaromatics bearing a hydroxyl group, 3-hydroxypyridinium salts, has been successfully developed using chiral iridium catalyst, providing a direct access to trans 6-substituted piperidin-3-ols with up to 95% ee. Swern oxidation of the hydrogenation products affords chiral 6-substituted piperidin-3-ones, which are easily reduced to cis 6-substituted piperidin-3-ols using K-selectride.

A new type of planar chiral Shvo catalysts, where the chirality is based solely on different substitution flanking the CO function, was prepared and used for transfer hydrogenation of imines and ketones. The reduction of ketimines represented by N-(1-phenylethylidene)aniline and prochiral ketones such as phenyl trifluoromethyl ketone with 2-propanol was efficiently catalyzed by 0.5 mol% of the chiral Shvo catalyst to give high yields of the corresponding reduction products with the enantioselectivities in the range 45% to 64% ee.

The hydrogenation rates of C=C and C=O bonds in methyl vinyl ketone and crotonaldehyde were measured over a series of silica-supported Pt-Re catalysts (1:1 atomic ratio of Pt/Re) in liquid water with H2 (15 psig) at 333 K. The hydrogenation of methyl vinyl ketone did not produce any unsaturated alcohol because of the rapid hydrogenation of C=C relative to that of C=O. The addition of Re to Pt impacted the rate of C=C hydrogenation negatively in methyl vinyl ketone and crotonaldehyde, but promoted the selectivity of C=O hydrogenation in crotonaldehyde in which the unsaturated alcohol increased from 5 % on Pt to 21 % on Pt-Re. The addition of Re to Pt also promoted the rate of C=O hydrogenation in 2-butanone, whereas little effect was observed during the hydrogenation of butanal. The results of electron microscopy and H2 chemisorption on the Pt-Re catalysts showed the increasing interaction between Pt and Re with the increasing metal weight loading, and results from rate measurements suggest that oxophilic Re can be used to promote the Pt-catalyzed hydrogenation of carbonyl groups in multifunctional molecules.

A photoactive catalyst, Fe@g-C3N4, has been developed for the hydrogenation of alkenes and alkynes using hydrazine hydrate as a source of hydrogen. The magnetically separable Fe@g-C3N4 eliminates the use of high pressure hydrogenation, and the reaction can be accomplished using visible light without the need for external sources of energy.

This paper presents the first systematic thermodynamic study of the vapour phase transfer hydrogenation of α,β-unsaturated carbonyl compounds at temperatures: 423.15–723.15 K. Calculations were made for four compounds, namely: acrolein, α-methylacrolein, β-methylacrolein and methyl vinyl ketone. The Gibbs free energies and equilibrium mole fractions (EMFs) were calculated for transfer hydrogenation with ethanol and 2-propanol as hydrogen donors. It was noted that for transfer hydrogenation and hydrogenation with hydrogen the formation of the unsaturated alcohol (UOL) is the least thermodynamically favoured reaction and that saturated alcohol (SOL) and saturated aldehyde or ketone (SAL or SON) are the main products. A set of eight carbonyl compounds have been transfer hydrogenated with ethanol and 2-propanol in the presence of MgO as the catalyst. The main conclusions are that: (a) the reduction of a carbonyl group into a carbinol group occurs with a very high selectivity, (b) for almost all carbonyl compounds, except acrolein, the reactivity of 2-propanol highly exceeded that shown by ethanol and (c) the high chemoselectivity of transfer hydrogenation of acrolein with alcohols resulted from the kinetic control caused by the presence of magnesium oxide.

Asymmetric hydrogenation of 4-substituted cyclic enamido esters catalyzed by a rhodium–TangPhos complex provides an efficient method for the synthesis of chiral 4-substituted oxazolinones with excellent yields and good enantioselectivities. The products are valuable chiral building blocks and the applications as chiral auxiliaries and pharmaceuticals are well-known.

Herein, we report the successful transformation of a 1(st) generation Grubbs metathesis catalyst into an asymmetric transfer hydrogenation (ATH) catalyst. Upon addition of a chiral amine ligand, an alcohol and a base, the 1(st) generation Hoveyda-Grubbs catalyst (HG-I) was found to promote the enantioselective reduction of acetophenone to 1-phenylethanol. After optimizing the order of addition and the reaction conditions, the substrate scope was assessed leading to enantiomeric excesses up to 97% ee. NMR experiments were run in order to get information about the in situ-generated ATH catalyst. Furthermore, the possibility to perform olefin metathesis and ketone transfer hydrogenation sequentially in one pot was demonstrated, and the first tandem olefin metathesis-ketone asymmetric transfer hydrogenation was carried out.

Effect of NH acidity on transfer hydrogenation of Noyori–Ikariya catalyst RuH(TsDPEN)(p-cymene) has been studied based on a series of tosylated ethylenediamine ligands (TsEN–Ph-X). Initial rates studies in both 2-propanol and 5:2 formic acid/triethylamine azeotrope show that catalysts containing less acidic NH groups afford better catalytic reactivities. The correlation of catalytic reactivities with the pKas of the NH groups shows a linear pattern in 2-propanol but a concave downwards relationship in azeotrope. These results lead to better understanding of the mechanism of Noyori–Ikariya’s catalyst and also aid in designing superior catalysts.

Novel catalysts consisting of ruthenium nanoparticles supported on diamond-like porous aromatic frameworks (PAFs) with 3 and 4 benzene rings in the edges have been synthetized with a narrow particle size distribution (0.85 and 1.10 nm respectively). Several techniques, such as N2 physisorption, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and solid-state nuclear magnetic resonance were used for characterizing the synthesized materials. The obtained catalysts appeared to be active in the hydrogenation of various aromatic substances (specific catalytic activity reached activities up to 2660 mol(Sub) h−1 mol (Ru) −1 in the case of phenol). Notably, a size-selective hydrogenation was observed for catalysts based on PAFs.

The synthesis of new enantiopure syn- and anti-3-(α-aminobenzyl)-benzo-γ-sultam ligands 6 and their application in the ruthenium(ii)-catalyzed asymmetric transfer hydrogenation (ATH) of ketones using formic acid/triethylamine is described. In particular, benzo-fused cyclic ketones afforded excellent enantioselectivities in reasonable time employing a low loading of the syn ligand-containing catalyst. A never-before-seen dynamic kinetic resolution (DKR) during reduction of a γ-keto carboxylic ester (S7) derivative of 1-indanone is realized leading as well to excellent induction.

A three-dimensional quantitative structure–selectivity relationship (3D-QSSR) model was developed to investigate the enantioselectivity in asymmetric ketone hydrogenation (AKH) catalyzed by RuH2(diphosphine)(diamine) complexes, through a comparative molecular field analysis (CoMFA). The predicted enantiomeric excess (ee) of the chiral alcohol products was in good agreement with the experimental ones, and the developed model showed good statistics in terms of correlation coefficients (q2 = 0.798, r2 = 0.996). The predictive power of the developed 3D-QSSR model was further proved by a test set of 5 ruthenium complexes, with an r2 of 0.974. The contour map analysis illustrated the sterically and electrostatically favored regions of the ruthenium catalysts for improving the enantioselectivity in the asymmetric hydrogenation. Under the guidance of the model, we modified the structure of the catalyst RuH2[(S)-tolbinap][(S,S)-dpen] (A1) to form the structure RuH2[(S)-tolbinap][(S,S)-dpen-NH2] (C1) where the aromatic rings of the dpen are substituted with amino groups in the para position. The theoretically predicted catalyst, C1, shows a theoretically calculated increase in the ee of AKH by 6.2%. In addition, a computational validation was performed for catalyst C1 under the density function theory (DFT), and a larger calculated difference in energy barriers in the hydrogen transfer step accounted for the enhanced enantioselectivity. In conclusion, the 3D-QSSR method could provide a plausible design criterion for the homogeneous transition-metal (TM) catalysts of asymmetric hydrogenation.

A method for enantioselective hydrogenation of cyclic imines with gaseous hydrogen has been developed. Easily accessible Noyori-Ikariya Ru(II) and Rh(III) complexes can be used directly without an inert atmosphere. Substrate activation has been achieved by trifluoroacetic acid. A new hydroxyl-functionalized complex is reported, showing high activity in transfer hydrogenation.

A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines has been successfully realized with 2.5 mol% of B(C6F5)3 as a catalyst to furnish a variety of 3,4-dihydro-2H-1,4-benzoxazines in 93-99% yields. Up to 42% ee was also achieved for the asymmetric hydrogenation with the use of a chiral diene and HB(C6F5)2.

A facile method for the preparation of heterogeneous asymmetric hydrogenation catalysts was presented. BINAP was knitted with aryl compounds using formaldehyde dimethyl acetal (FDA) as a cross-linker by Friedel–Crafts reaction without any pre-modification. The prepared catalysts showed different catalytic activities, and excellent recyclablilty results could be achieved in asymmetric hydrogenation.

Novel pyridylalkylamine and aminopyridinato ligand stabilized iridium complexes with no P ligand are introduced. These complexes have been investigated as catalysts for asymmetric hydrogenation of simple ketones, resulting in an active catalyst for bulky alkyl aryl ketones that is α-methylpropiophenone. The ligands were synthesized from inexpensive starting materials and their modular design allows for the introduction of a broad variety of substitution patterns. Additionally, better activity and selectivity was observed at 20 °C and 20 bar H2 pressure with a catalyst loading as low as 0.05 mol% iridium. These phosphorus free catalysts have always been a central issue in both academic and industrial research.

This paper describes the first metal-free hydrogenation of 3,6-diarylpyridazines, which was successfully realized using B(C6F5)3 as a catalyst. A variety of 1,4,5,6-tetrahydropyridazine derivatives were furnished in 85-95% yields.

The liquid-phase hydrogenation of aromatic trinitro compounds was studied at atmospheric and elevated pressure and a temperature of 50–70 °C. It was shown that at atmospheric pressure, irrespective of the solvent type (water or acetic anhydride), a complete reduction of the nitro groups of 2,4,6-trinitrobenzoic acid to amino groups does not occur; the intermediate products of hydrogenation and the products of secondary transformations are present in the solution. An increase in pressure to 5 bars ensures a complete hydrogenation of 2,4,6-trinitrobenzoic acid and 1,3,5-trinitrobenzene with the formation of 1,3,5-triaminobenzene.

A copper-doped porous metal oxide catalyst in combination with hydrogen shows selective and quantitative hydrogenolysis of benzyl ketones and aldehydes, and hydrogenation of alkenes. The approach provides an alternative to noble-metal catalysed reductions and stoichiometric Wolff-Kishner and Clemmensen methods.

Hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) was studied by using mono- and bidentate p-cymene ruthenium(ii) N-heterocyclic carbene (NHC) complexes as catalyst precursors. In water, all complexes were found to be reduced in situ to form ruthenium nanoparticles (RuNPs) with a high hydrogenation activity. In organic solvents, complexes with monodentate NHC ligands also formed nanoparticles, while complexes with bidentate ligands gave rise to stable homogeneous catalysts with moderate hydrogenation activities.

In the same catalytic system, thermoregulated ligand Ph2P(CH2CH2O)22CH3-stabilized iridium nanoparticles exhibited a totally different orientation for the hydrogenation of unsaturated carbonyl compounds, namely, highly selective hydrogenation of the CO bond for α,β-unsaturated aldehydes and the CC bond for α,β-unsaturated ketones.

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.

The ruthenium(II) complex cis-[RuCl2(PPh3)2(L1)] (1) where L1 = 2-(2’-pyridyl)quinoline was obtained in high yield from the reaction of [RuCl2(PPh3)3] with L1. The new compound was characterized by different spectroscopic methods including FT-IR, UV-Vis, NMR (1H, 31P) spectroscopy along with a mass spectrometric analysis (ESI-MS) and conductivity measurements. 31P NMR spectroscopy provided evidence that the two PPh3 ligands are orientated trans to each other in an octahedral environment. Complex (1) was tested in the transfer hydrogenation of various ketones in 2-propanol at 82 oC. The catalytic activity of (1) displayed quantitative conversions for benzophenone and 4-chloroacetophenone.

This digest Letter comprises recent advances in the synthesis of chiral building blocks that uses rhodium catalyzed asymmetric hydrogenation of olefins. The first part of this revision covers the examples that have broadened the scope of the hydrogenation of enamides and enol esters. The second part focuses on the hydrogenation of alternative classes of substrates like unsaturated carboxylic acids, nitroderivatives or phosphonates among others. Overall, the diversity of structures and functional groups of substrates, along with the outstanding levels of catalyst efficiency shown in these contributions, have further established this reaction as a most valuable tool in asymmetric synthesis.

Selective hydrogenation of aromatic ketones and phenols by the reduction of aromatic groups, with the retention of an easily reducible carbonyl functionality in the final products, provides a practically useful route to fundamentally interesting cyclohexyl ketones and cyclohexanones, but the achievement thereof remains a great challenge. Recently, however, much progress in this area has been made with the use of rhodium and palladium catalysis. We now highlight the achievements made in the selective hydrogenation of aromatic ketones and phenols by reduction of the aromatic motifs. 1 Introduction 2 Chemoselective Hydrogenation of Aromatic Ketones by Reducing the Aromatic Scaffolds 3 Selective Hydrogenation of Phenols to Cyclohexanones 4 Conclusion

The catalytic hydrogenation of benzodiazepinones using metal complexes with phosphite and phosphoramidite ligands was carried out for the first time. The mixed-ligand catalytic systems containing a chiral phosphoramidite or phosphite in combination with an achiral phosphine were shown to exhibit a higher enantioselectivity compared to catalysts containing homocombinations of chiral ligands.

Asymmetric hydrogenation of 1-silyl-1-substituted alkenes has been explored, producing eight optically active silanes with good to excellent enantioselectivity (66–99% ee) and yield (74–99%). The reaction was efficiently catalyzed by the cationic N,P-Ir complexes, and the polar solvents were found to be essential for the stereocontrol of the conversion.

International audience; The reduction of ketones with 2-propanol as reductant was achieved using an in-situ generated catalytic system based on manganese pentacarbonyl bromide, as metal precursor, and ethylenediamine as ligand. The reaction proceeds in high yield at 80 °C, in 3 h, with 0.5 mol% of catalyst. In the presence of chiral (1R,2R)-N,N′-dimethyl-1,2-diphenylethane-1,2-diamine, as the ligand, sterically hindered alcohols were produced with enantiomeric excess up to 90%.