131380-91-1

Upstream product

• 2026-48-4 (S)-valinol 
• 69-72-7 salicylic acid 
• 72-18-4 L-valine 
• 611-20-1 salicylonitrile 

Downstream Products

• 209850-73-7 (+)-(4'S)-2-(4'-isopropyl-3',4'-dihydrooxazol-2'-yl)aniline 

Relevant academic research and scientific papers

PHOX-Based Phosphite-Oxazoline Ligands for the Enantioselective Ir-Catalyzed Hydrogenation of Cyclic Β-Enamides

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

Enantioselective Excited-State Photoreactions Controlled by a Chiral Hydrogen-Bonding Iridium Sensitizer

Stereochemical control of electronically excited states is a long-standing challenge in photochemical synthesis, and few catalytic systems that produce high enantioselectivities in triplet-state photoreactions are known. We report herein an exceptionally effective chiral photocatalyst that recruits prochiral quinolones using a series of hydrogen-bonding and π-π interactions. The organization of these substrates within the chiral environment of the transition-metal photosensitizer leads to efficient Dexter energy transfer and effective stereoinduction. The relative insensitivity of these organometallic chromophores toward ligand modification enables the optimization of this catalyst structure for high enantiomeric excess at catalyst loadings as much as 100-fold lower than the optimal conditions reported for analogous chiral organic photosensitizers.

Alternatives to Phosphinooxazoline (t-BuPHOX) Ligands in the Metal-Catalyzed Hydrogenation of Minimally Functionalized Olefins and Cyclic β-Enamides

This study presents a new series of readily accessible iridium- and rhodium-phosphite/oxazoline catalytic systems that can efficiently hydrogenate, for the first time, both minimally functionalized olefins and functionalized olefins (62 examples in total) in high enantioselectivities (ees up to >99%) and conversions. The phosphite-oxazoline ligands, which are readily available in only two synthetic steps, are derived from previous privileged 4-alkyl-2-[2-(diphenylphosphino)phenyl]-2-oxazoline (PHOX) ligands by replacing the phosphine moiety by a biaryl phosphite group and/or the introduction of a methylene spacer between the oxazoline and the phenyl ring. The modular design of the ligands has given us the opportunity not only to overcome the limitations of the iridium-PHOX catalytic systems in the hydrogenation of minimally functionalized Z-olefins and 1,1-disubstituted olefins, but also to expand their use to unfunctionalized olefins containing other challenging scaffolds (e.g., exocyclic benzofused and triaryl-substituted olefins) and also to olefins with poorly coordinative groups (e.g., α,β-unsaturated lactams, lactones, alkenylboronic esters, etc.) with enantioselectivities typically >95% ee. Moreover, both enantiomers of the hydrogenation product could be obtained by simply changing the configuration of the biaryl phosphite moiety. Remarkably, the new catalytic systems also provided excellent enantioselectivities (up to 99% ee) in the asymmetric hydrogenation of another challenging class of olefins – the functionalized cyclic β-enamides. Again, both enantiomers of the reduced amides could be obtained by changing the metal from Ir to Rh. We also demonstrated that environmentally friendly propylene carbonate can be used with no loss of enantioselectivity. Another advantage of the new ligands over the PHOX ligands is that the best ligands are derived from the affordable (S)-phenylglycinol rather than from the expensive (S)-tert-leucinol. (Figure presented.).

Synthesis of Air- and Moisture-Stable, Storable Chiral Oxorhenium Complexes and Their Application as Catalysts for the Enantioselective Imine Reduction

Air-/moisture-stable, crystalline, and storable chiral salicyloxazoline based oxorhenium(V) complexes have been synthesized and their catalytic application for the asymmetric reduction of ketimines using hydrosilane as hydride source is disclosed. A broad substrate scope, high yields, and excellent enantioselectivities (up to 99 %) are attained. Furthermore, the syntheses of enantiopure α-amino esters, γ- and δ-lactams, and isoindolinones have also been carried out using this methodology. Finally, the method has been applied to synthetic targets of pharmaceutical relevance, such as R-(+)-salsolidine and R-(+)-crispine A.

Rhenium-catalyzed oxidative cyanation of tertiary amines with TMSCN

Oxidative cyanation of sp3 C-H bonds at the α position of tertiary amines by using TMSCN as the cyanide donor and a novel high-valent rhenium(V) complex was developed. The reaction offers the corresponding α-aminonitriles in good yields with tert-butyl hydroperoxide as the oxidant under mild and acid-free reaction conditions. Oxidative cyanation of sp3 C-H bonds at the α position of tertiary amines by using TMSCN as the cyanide donor and novel high-valent rhenium(V) complex catalysts is developed. The reactions offer the corresponding α-aminonitriles in good yields by using tert-butyl hydroperoxide as the oxidant under mild and acid-free reaction conditions at room temperature. Copyright

Enantioselective Cu-catalyzed 1,4-addition of Me3 Al to a 4,4-disubstituted cyclohexa-2,5-dienone

A series of chiral enantiomerically pure 2-aryloxazolines was synthesized. (4S)-2-(2',6'-dimethoxyphenyl)-4-isopropyloxazoline proved to be an efficient chiral ligand for the Cu-catalyzed conjugate addition of Me3Al to cyclohexadienone, and by using 20 mol% of this ligand, 1,4-adduct was obtained in 68% ee. In addition, TBDMSOTf is crucial for the asymmetric conjugate addition to proceed with good chemical yield and high ee.

Enantiomerically pure oxazolines tethered to alcohols. Preparation and use in asymmetric catalysis

A series of enantiomerically pure oxazolines tethered to alcohols have been prepared. The use of these oxazolines has been demonstrated in the catalysed addition of diethylzine to aromatic aldehydes to afford the corresponding secondary alcohols with modest levels of asymmetric induction.

Synthesis of Optically Active Bis(2-oxazolines): Crystal Structure of a 1,2-Bis(2-oxazolinyl)benzene * ZnCl2 Complex

Dinitriles (5-7, 12, 13) react with enantiomerically pure β-amino alcohols (8-11, 17) under zinc chloride catalysis to give optically active C2-symmetric bis(oxazolines). 1,2-Bis(2-oxazolin-2-yl)benzenes 1a-e are obtained under mild reaction conditions. 1H-NMR spectroscopy indicates the formation of 1:1 complexes 23 of these compounds with ZnCl2.The energy required for a conformational interconversion of zinc dichloride complex 23e was determined by variable-temperature 1H-NMR studies.An X-ray structure analysis was performed with the substituted zinc dichloride complex 23a.