112710-41-5

Upstream product

• 105-05-5 1,4-diethylbenzene 
• 108124-68-1 α,α'-dimethyl-1,4-benzenedimethanol diacetate 
• 1009-61-6 1,4-Diacetylbenzene 
• 108-22-5 Isopropenyl acetate 
• 6781-43-7 1,4-bis(1-hydroxyethyl)benzene 
• 143329-79-7 meso-α,α’-dimethyl-(1,4-benzene)dimethanol monoacetate 
• 912334-66-8 C₁₈H₂₆O₄ 
• 143329-80-0 (R,R)-α,α'-dimethyl-1,4-benzenedimethanol diacetate 

Downstream Products

• 108673-17-2 (R)-1-[4-(1-hydroxyethyl)phenyl]ethan-1-one 
• 909295-66-5 1-[(R)-1-(isobutyryloxy)ethyl]-4-[(S)-1-hydroxyethyl]benzene 

Relevant academic research and scientific papers

Aerobic oxidative desymmetrization of meso-diols with bifunctional amidoiridium catalysts bearing chiral N-sulfonyldiamine ligands

Asymmetric aerobic oxidation of a range of meso- and prochiral diols with chiral bifunctional Ir catalysts is described. A high level of chiral discrimination ability of Cpa? -Ir complexes derived from (S,S)-1,2-diphenylethylenediamine was successfully demonstrated by desymmetrization of secondary benzylic diols such as cis-indan-1,3-diol and cis-1,4-diphenylbutane-1,4-diol, providing the corresponding (R)-hydroxyl ketones with excellent chemo- and enantioselectivities. Enantiotopic group discrimination in oxidation of symmetrical primary 1,4- and 1,5-diols gave rise to chiral lactones with moderate ees under similar aerobic conditions.

Varying the ratio of formic acid to triethylamine impacts on asymmetric transfer hydrogenation of ketones

Asymmetric transfer hydrogenation (ATH) is frequently carried out in the azeotropic mixture of formic acid (F) and triethylamine (T), where the F/T molar ratio is 2.5. This study shows that the F/T ratio affects both the reduction rate and enantioselectivity, with the optimum ratio being 0.2 in the ATH of ketones with the Ru-TsDPEN catalyst. Under such conditions, a range of substrates have been reduced, affording high yields and good to excellent enantioselectivities. In comparison with the common azeotropic F-T system, the reduction is faster. This protocol improves both the classic azeotropic and the aqueous-formate system when using water-insoluble ketones.

Asymmetric synthesis of chiral tectons with tetrapodal symmetry: Fourfold asymmetric reactions

The diastereoselective fourfold addition to Ellman-type imines furnished after deprotection the tetrapodal amines in excellent yields. The unprecedented asymmetric fourfold addition of hydride and alkylzinc reagents to tetrapodal ketones and aldehydes, respectively, is achieved by employing CBS-reduction or [2.2]paracyclophane-based ketimine ligands with good to excellent global enantiomeric ratios.

Process for the preparation of an optically active ester

The invention relates to a process for the preparation of an optically active compound from raw materials comprising a di-ester and a chiral hydroxy-compound according to formula (I): wherein: - R1, R2, R4 and R5/sub

Combined ruthenium(II) and lipase catalysis for efficient dynamic kinetic resolution of secondary alcohols. Insight into the racemization mechanism

Pentaphenylcyclopentadienyl ruthenium complexes (3) are excellent catalysts for the racemization of secondary alcohols at ambient temperature. The combination of this process with enzymatic resolution of the alcohols results in a highly efficient synthesis of enantiomerically pure acetates at room temperature with short reaction times for most substrates. This new reaction was applied to a wide range of functionalized alcohols including heteroaromatic alcohols, and for many of the latter, enantiopure acetates were efficiently prepared for the first time via dynamic kinetic resolution (DKR). Different substituted cyclopentadienyl ruthenium complexes were prepared and studied as catalysts for racemization of alcohols. Pentaaryl-substituted cyclopentadienyl complexes were found to be highly efficient catalysts for the racemization. Substitution of one of the aryl groups by an alkyl group considerably slows down the racemization process. A study of the racemization of (S)-1-phenylethanol catalyzed by ruthenium hydride η5-Ph5CpRu(CO) 2H (8) indicates that the racemization takes place within the coordination sphere of the ruthenium catalyst. This conclusion was supported by the lack of ketone exchange in the racemization of (S)-1-phenylethanol performed in the presence of p-tolyl methyl ketone (1 equiv), which gave 1% of 1-(p-tolyl)ethanol. The structures of ruthenium chloride and iodide complexes 3a and 3c and of ruthenium hydride complex 8 were confirmed by X-ray analysis.

Aminocyclopentadienyl Ruthenium Complexes as Racemization Catalysts for Dynamic Kinetic Resolution of Secondary Alcohols at Ambient Temperature

Aminocyclopentadienyl ruthenium complexes, which can be used as room-temperature racemization catalysts with lipases in the dynamic kinetic resolution (DKR) of secondary alcohols, were synthesized from cyclopenta-2,4-dienimines, Ru3(CO)12, and CHCl 3: [2,3,4,5-Ph4(η5-C 4CNHR)]Ru-(CO)2Cl (4: R = i-Pr; 5: R = n-Pr; 6: R = t-Bu), [2,5-Me2-3,4-Ph2(η5-C 4CNHR)]Ru(CO)2Cl (7: R = i-Pr; 8: R = Ph), and [2,3,4,5-Ph4(η5-C4CNHAr)]Ru(CO) 2Cl (9: Ar =p-NO2C6H4; 10: Ar = p-ClC6H4; 11: Ar = Ph; 12: Ar = p-OMeC6H 4; 13: Ar = p-NMe2C6H4). The tests in the racemization of (S)-4-phenyl-2-butanol showed that 7 is the most active catalyst, although the difference decreased in the DKR. Complex 4 was used in the DKR of various alcohols; at room temperature, not only simple alcohols but also functionalized ones such as allylic alcohols, alkynyl alcohols, diols, hydroxyl esters, and chlorohydrins were successfully transformed to chiral acetates. In mechanistic studies for the catalytic racemization, ruthenium hydride 14 appeared to be a key species. It was the major organometallic species in the racemization of (S)-1-phenylethanol with 4 and potassium tert-butoxide. In a separate experiment, (S)-1-phenylethanol was racemized catalytically by 14 in the presence of acetophenone.

An efficient preparation of optically pure C2-symmetric aromatic diols by the asymmetric reduction of diacylaromatic compounds with B- chlorodiisopinocampheylborane

Asymmetric reduction of diacylaromatic compounds with B- chlorodiisopinocampheylborane provides the product diols in excellent diastereomeric and enantiomeric purity.

Separation of Remote Diol and Triol Stereoisomers by Enzyme-Catalyzed Esterification in Organic Media or Hydrolysis in Aqueous Media

The separation of symmetric, remote, secondary diol stereoisomers by stereoselective enzyme-catalyzed acetylation with acetic anhydride in anhydrous, low polarity organic solvents or by stereoselective enzyme-catalyzed hydrolysis of the corresponding pera

Separation and Characterization of All Configurational Isomers by Enzymatic Discrimination of Each Chiral Function

An enzymatic method for simultaneous performance of separation and analysis of (meso/racemic)-diesters, i.e. 1,4-bis(1-acetoxyethyl)benzene (3a) and 1,4-bis-(1-acetoxyisopropyl)benzene (3b), was demeonstrated. Key Words: lipases; separation; meso and racemic mixtures; p-disubstituted benzenes; chiral centers