58396-29-5

Upstream product

• 108-22-5 Isopropenyl acetate 
• 1193-81-3 rac-1-cyclohexylethanol 
• 108-05-4 vinyl acetate 
• 3113-99-3 (R)-1-cyclohexylethanol 
• 876-27-7 4-chlorophenyl acetate 
• 823-76-7 Cyclohexyl methyl ketone 
• 52789-67-0 Acetic acid 1-cyclohexylidene-ethyl ester 
• 108-24-7 acetic anhydride 
• 2043-61-0 cyclohexanecarbaldehyde 
• 931-48-6 2-cyclohexylacetylene 
• 64-19-7 acetic acid 
• 3113-98-2 (S)-(+)-1-cyclohexylethanol 
• 104-15-4 toluene-4-sulfonic acid 
• 103262-97-1 1-cyclohexylvinyl acetate 

Downstream Products

• 3113-99-3 (R)-1-cyclohexylethanol 

Relevant academic research and scientific papers

Asymmetric Chemoenzymatic Reductive Acylation of Ketones by a Combined Iron-Catalyzed Hydrogenation–Racemization and Enzymatic Resolution Cascade

A general and practical process for the conversion of prochiral ketones into the corresponding chiral acetates has been realized. An iron carbonyl complex is reported to catalyze the hydrogenation–dehydrogenation–hydrogenation of prochiral ketones. By merging the iron-catalyzed redox reactions with enantioselective enzymatic acylations a wide range of benzylic, aliphatic and (hetero)aromatic ketones, as well as diketones, were reductively acylated. The corresponding products were isolated with high yields and enantioselectivities. The use of an iron catalyst together with molecular hydrogen as the hydrogen donor and readily available ethyl acetate as acyl donor make this cascade process highly interesting in terms of both economic value and environmental credentials.

Catalytic Asymmetric Addition of Organolithium Reagents to Aldehydes

Herein we report an efficient catalytic system for the titanium-promoted enantioselective addition of organolithium reagents to aldehydes, based on chiral Ar-BINMOL ligands. Unprecedented yields and enantioselectivities are achieved in the alkylation reactions of aliphatic aldehydes. Remarkably, methyllithium can be added to a wide variety of aromatic and aliphatic aldehydes, providing versatile chiral methyl carbinol units in a simple one-pot procedure under mild conditions and in very short reaction times.

Catalytic enantioselective addition of methyltriisopropoxititanium to aldehydes

An efficient catalyst for the enantioselective synthesis of chiral methyl carbinols from aldehydes is presented. The system uses methyltriisopropoxytitanium as a nucleophile and a readily available binaphthyl derivative as a chiral ligand. The enantioselective methylation of both aromatic and aliphatic aldehydes proceeds with good yields and high enantioselectivities under mild conditions.

Mechanochemical Enzymatic Kinetic Resolution of Secondary Alcohols under Ball-Milling Conditions

Mechanosynthesis is a valuable technique, offering attractive alternatives for the preparation of organic, inorganic, and organometallic products. Surprisingly, mechanochemical enzymatic transformations have only scarcely been studied until now. Here, we demonstrate the use of lipase B from Candida antarctica (CALB) in acylative kinetic resolutions of secondary alcohols in mixer and planetary mills. Despite the mechanical stress caused by the high-speed ball milling, the biocatalyst proved highly effective, stable, and, in part, recyclable under the applied mechanochemical conditions. Best milling practice: The compatibility of lipase B from Candida antarctica (CALB) in acylative kinetic resolutions of secondary alcohols in mixer and planetary mills has been explored. Despite the mechanical stress caused by the high-speed ball milling, the biocatalyst was found to be very effective, stable, and, in part, recyclable under the applied mechanochemical conditions.

Iridium-Catalyzed Asymmetric Hydrogenation with Simple Cyclohexane-Based P/S Ligands: In Situ HP-NMR and DFT Calculations for the Characterization of Reaction Intermediates

We report a reduced but structurally valuable phosphite/phosphinite-thioether ligand library for the Ir-hydrogenation of 40 minimally functionalized alkenes, including relevant examples with poorly coordinative groups. We found that enantiomeric excesses are mainly dependent on the substrate structure and on some ligand parameters (i.e., the type of thioether/phosphorus moieties and the configuration of the phosphite group), whereas the substituents of the biaryl phosphite moiety had little impact. By tuning the ligand parameters we were able to find highly selective catalysts for a range of substrates (ees up to 99%). These phosphite/phosphinite-thioether ligands have a simple backbone and thus yield simple NMR spectra that reduce signal overlap and facilitate the identification of relevant intermediates. Therefore, by combining HP-NMR spectroscopy and theoretical studies, we were also able to identify the catalytically competent Ir-dihydride alkene species, which made it possible to explain the enantioselectivity obtained.

Core-Shell Composite as the Racemization Catalyst in the Dynamic Kinetic Resolution of Secondary Alcohols

Beta-Silicalite-1 core-shell microcomposites with controllable shell thickness were synthesized and used as racemization catalysts in the one-pot dynamic kinetic resolution (DKR) of secondary alcohols by using lipase-catalyzed transesterification. The inert Silicalite-1 shell covered the external acidic sites of the Beta zeolite core, suppressing dehydration and non-enantioselective transesterification of the alcohol. The alcohols could penetrate the Silicalite-1 shell to access the acidic sites at the core Beta for racemization, however, the enzymatically formed (R)-esters were excluded owing to their larger size. As a result, the high ee of the (R)-ester products was conserved and dehydration side products were minimized. Owing to the shape selective nature of the composite racemization catalyst, small and readily available acyl donors could be used in the enzyme-catalyzed transesterification to obtain the esters with high enantiopurity. The DKR of 1-phenylethanol with isopropenyl acetate using an optimized core-shell catalyst, CS-60, gave 92% selectivity to ester formation and the desired (R)-1-phenylethyl acetate was formed with 94% ee.

Highly enantioselective Rh-catalysed hydrogenation of 1-alkyl vinyl esters using phosphine-phosphoramidite ligands

MatPhos, a good mate for hard tasks: The asymmetric hydrogenation of 1-alkyl vinyl esters, thwarted so far by mediocre ee values and low activities, can now be achieved with MatPhos/Rh catalysts with ee values of 96-99 % for a variety of substrates at low catalyst loadings (0.1-1 mol %) and under mild conditions (5-20 bar H2, room temperature). After hydrolysis, the corresponding chiral secondary alkyl alcohols can be obtained in high enantiopurities providing a general and practical route to this important product class. Copyright

Application of tethered ruthenium catalysts to asymmetric hydrogenation of ketones, and the selective hydrogenation of aldehydes

An improved method for the synthesis of tethered ruthenium(II) complexes of monosulfonylated diamines is described, together with their application to the hydrogenation of ketones and aldehydes. The complexes were applied directly, in their chloride form, to asymmetric ketone hydrogenation, to give products in excess of 99% ee in the best cases, using 30 bar of hydrogen at 60 °C, and to the selective reduction of aldehydes over other functional groups. Copyright

Application of ruthenium complexes of triazole-containing tridentate ligands to asymmetric transfer hydrogenation of ketones

The synthesis of a series of tridentate ligands based on a homochiral 1,2-diamine structure attached to a triazole group and their subsequent applications to the asymmetric transfer hydrogenation of ketones are described. In the best cases, alcohols of up to 93% ee were obtained. Although base is not required, the use of Ru3(CO)12 as metal source is essential, indicating a unique mechanism for the formation of the active catalyst.

Application of tethered ruthenium catalysts to asymmetric hydrogenation of ketones, and the selective hydrogenation of aldehydes

An improved method for the synthesis of tethered ruthenium(II) complexes of monosulfonylated diamines is described, together with their application to the hydrogenation of ketones and aldehydes. The complexes were applied directly, in their chloride form, to asymmetric ketone hydrogenation, to give products in excess of 99% ee in the best cases, using 30 bar of hydrogen at 60 °C, and to the selective reduction of aldehydes over other functional groups. Copyright