105663-24-9

Upstream product

• 108-05-4 vinyl acetate 
• 1460-57-7 trans-1,2-cyclohexandiol 
• 1759-71-3 trans-1,2-cyclohexanediol diacetate 
• 130464-07-2 (R,R)-1,2-diacetoxycyclohexane 
• 286-20-4 cyclohexane-1,2-epoxide 
• 141-78-6 ethyl acetate 
• 64-19-7 acetic acid 
• 110-83-8 cyclohexene 
• 108-24-7 acetic anhydride 
• 62921-46-4 trans-2-acetoxy-1-cyclohexanol 
• 75-36-5 acetyl chloride 
• 1792-81-0 cis-1,2-cyclohexane 
• 830-03-5 4-nitrophenol acetate 
• 100-51-6 benzyl alcohol 

Downstream Products

• 1072-86-2 (1R,2R)-trans-1,2-cyclohexanediol 
• 131139-94-1 (1'R,2'R,3S)-2'-hydroxycyclohexyl 3-methylheptanoate 
• 131140-03-9 (1R,2R)-2-hydroxycyclohexyl (E)-cinnamate 
• 131140-04-0 (1R,2R)-2-hydroxycyclohexyl (E)-2-pentenoate 
• 131140-02-8 (1R,2R)-2-hydroxycyclohexyl crotonate 
• 64363-90-2 (+)-(2R)-2-acetoxycyclohexanone 

Relevant academic research and scientific papers

Functionality, Effectiveness, and Mechanistic Evaluation of a Multicatalyst-Promoted Reaction Sequence by Electrospray Ionization Mass Spectrometry

A multicatalytic three-step reaction consisting of epoxidation, hydrolysis, and enantioselective monoacylation of cyclohexene was studied by using mass spectrometry (MS). The reaction sequence was carried out in a one-pot reaction using a multicatalyst. All reaction steps were thoroughly analyzed by electrospray ionization (ESI) MS (and MS/MS), as well as high-resolution MS for structure elucidation. These studies allow us to shed light on the individual mode of action of each catalytic moiety. Thus, we find that under the epoxidation conditions, the catalytically active N-methyl imidazole for the terminal acylation step is partially deactivated through oxidation. This observation helps to explain the lower efficiency of the catalyst in the last step compared to the monoacylation performed separately. All reactive intermediates and products of the reaction sequence, as well as of the side-reactions, were monitored, and we present a working mechanism of the reaction.

Asymmetric Hydrolyses of 1,2-Diacetoxycyclohexanes by the Cultured Suspension Cells of Marchantia polymorpha

The enantioselectivity in the hydrolyses of cis- and trans-1,2-diacetoxycyclohexanes by the cultured suspension cells of Marchantia polymorpha was very high.The acetoxyl groups at the stereogenic center of (R)-configuration were preferentially hydrolyzed.

An Insight into Enantioselective Hydrolyses of Cyclic Acetates Catalysed by Pseudomonas Fluorescens Lipase

Hydrolysis of racemic acetates with Pseudomonas fluorescens lipase (PFL) afforded optically active alcohols with the R-configuration, independent of ring size; a three-site model for PFL-catalysed hydrolysis is proposed.

A photoinduced cyclization cascade - Total synthesis of (-)-leuconoxine

A protecting-group-free and enantioselective total synthesis of the monoterpenoid indole alkaloid (-)-leuconoxine was accomplished. The key step comprises a novel photoinduced domino macrocyclization/transannular cyclization involving the Witkop cyclization, for which additional mechanistic evidence is provided. This process furnishes a diaza[5.5.6.6]fenestrane skeleton, which is a hitherto unprecedented structure element.

An Optimized Sequential Kinetic Resolution of trans-1,2-Cyclohexanediol

Quantitative analysis of sequential kinetic resolutions (resolutions that proceed via two or more enantioselective steps) indicates that optimal reinforcement of the enantioselectivities occurs when the rates of the two steps are equal.Unter these conditions, the reinforcement is multiplicative and the overall enantioselectivity, ET(max), is given approximately by 1E2)>/2.To test these ideas we optimized the resolution of trans-1,2-cyclohexanediol, 1.The first step of the porcine liver esterase (PLE) catalyzed hydrolysis of trans-1,2-diacetoxycyclohexane proceeded 47 times faster than the second step and the resolution yielded 1 with only 58 percent ee at 44 molpercent.Addition of a hexane phase slowed the first step by selectively extracting the fast-reaction 1-diacetate (relative rate = 6) and increased the enantiomeric purity to 94 percent ee at 34 molpercent.The resolution of 1 was further improved using lipase from Pseudomonas cepacia (Amano P, PCL) which showed an ET(max) of >2000 as compared to an ET(max) for PLE of 54.Resolution with PCL after equalization of the rates of the two steps gave (R)-1 and recovered (S)-1-diacetate both with >99 percent ee.

Uncovering Key Structural Features of an Enantioselective Peptide-Catalyzed Acylation Utilizing Advanced NMR Techniques

We report on a detailed NMR spectroscopic study of the catalyst-substrate interaction of a highly enantioselective oligopeptide catalyst that is used for the kinetic resolution of trans-cycloalkane-1,2-diols via monoacylation. The extraordinary selectivity has been rationalized by molecular dynamics as well as density functional theory (DFT) computations. Herein we describe the conformational analysis of the organocatalyst studied by a combination of nuclear Overhauser effect (NOE) and residual dipolar coupling (RDC)-based methods that resulted in an ensemble of four final conformers. To corroborate the proposed mechanism, we also investigated the catalyst in mixtures with both trans-cyclohexane-1,2-diol enantiomers separately, using advanced NMR methods such as T1relaxation time and diffusion-ordered spectroscopy (DOSY) measurements to probe molecular aggregation. We determined intramolecular distance changes within the catalyst after diol addition from quantitative NOE data. Finally, we developed a pure shift EASY ROESY experiment using PSYCHE homodecoupling to directly observe intermolecular NOE contacts between the trans-1,2-diol and the cyclohexyl moiety of the catalyst hidden by spectral overlap in conventional spectra. All experimental NMR data support the results proposed by earlier computations including the proposed key role of dispersion interaction.

Alcohol cross-coupling for the kinetic resolution of diols via oxidative esterification

We present an organocatalytic C-O-bond cross-coupling strategy to kinetically resolve racemic diols with aromatic and aliphatic alcohols, yielding enantioenriched esters. This one-pot protocol utilizes an oligopeptide multicatalyst, m-CPBA as the oxidant, and N,N-diisopropylcarbodiimide as the activating agent. Racemic acyclic diols as well as trans-cycloalkane-1,2-diols were kinetically resolved, achieving high selectivities and good yields for the products and recovered diols.

Highly enantioselective organocatalytic oxidative kinetic resolution of secondary alcohols using chiral alkoxyamines as precatalysts: Catalyst structure, active species, and substrate scope

The development and characterization of enantioselective organocatalytic oxidative kinetic resolution (OKR) of racemic secondary alcohols using chiral alkoxyamines as precatalysts are described. A number of chiral alkoxyamines have been synthesized, and their structure-enantioselectivity correlation study in OKR has led us to identify a promising precatalyst, namely, 7-benzyl-3-n-butyl-4-oxa-5-azahomoadamantane, which affords various chiral aliphatic secondary alcohols (ee up to >99%, krel up to 296). In a mechanistic study, chlorine-containing oxoammonium species were identified as the active species generated in situ from the alkoxyamine precatalyst, and it was revealed that the chlorine atom is crucial for high reactivity and enantioselectivity. The present OKR is the first successful example applicable to various unactivated aliphatic secondary alcohols, including heterocyclic alcohols with high enantioselectivity, the synthetic application of which is demonstrated by the synthesis of a bioactive compound.

Organocatalytic asymmetric hydrolysis of epoxides

The hydrolytic ring opening of epoxides is an important biosynthetic transformation and is also applied industrially. We report the first organocatalytic variant of this reaction, exploiting our recently discovered activation of carboxylic acids with chiral phosphoric acids via heterodimerization. The methodology mimics the enzymatic mechanism, which involves an enzyme-bound carboxylate nucleophile. A newly designed phosphoric acid catalyst displays high stereocontrol in the desymmetrization of meso-epoxides. The methodology shows wide generality with cyclic, acylic, aromatic, and aliphatic substrates. We also apply our method in the first highly enantioselective anti-dihydroxylation of simple olefins.

Lipophilic oligopeptides for chemo- and enantioselective acyl transfer reactions onto alcohols

Inspired by the extraordinary selectivities of acylases, we envisioned the use of lipophilic oligopeptidic organocatalysts for the acylative kinetic resolution/desymmetrization of rac- and meso-cycloalkane-1,2-diols. Here we describe in a full account the discovery and development process from the theoretical concept to the final catalyst, including scope and limitations. Competition experiments with various alcohols and electrophiles show the full potential of the employed oligopeptides. Additionally, we utilized NMR and IR-spectroscopic methods as well as computations to shed light on the factors responsible for the selectivity. The catalyst system can be readily modified to a multicatalyst by adding other catalytically active amino acids to the peptide backbone, enabling the stereoselective one-pot synthesis of complex molecules from simple starting materials.