Stereoisomer-differentiating esterification of diols with methylboronic acid. A simple method for the separation of cis- and trans-1,2-diols

Roy, Chandra D.; Brown, Herbert C.

doi:10.1016/j.tetlet.2007.01.070

Cited by 8 publications

(9 citation statements)

References 13 publications

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“…However, even the relatively small energetic penalties associated with strained surface–adsorbate bonds or a conformational change from the lowest energy chair conformation to a twist-boat conformation impact the reaction energetics sufficiently to change the product distribution. These conclusions mirror past results from other fields of chemistry, showing that stereo, structural, or conformational isomerism can affect the stability of chelated organometallic complexes − or reaction selectivity − , in solution, and they extend these basic principles to reactions of organic molecules at a crystalline surface. By changing one or both of the functional groups or modifying the molecular backbone to impose additional geometric constraints, one may be able to leverage the different reactivities of the various isomers to achieve high regioselectivity or stereoselectivity of reaction with the Ge(100)-2 × 1 surface.…”

Section: Discussionsupporting

confidence: 85%

Adsorption of Structural and Stereoisomers of Cyclohexanediamine at the Ge(100)-2 × 1 Surface: Geometric Effects in Adsorption on a Semiconductor Surface

Wong

Bent

2013

J. Phys. Chem. C

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The effects of structural isomerism and stereoisomerism in molecular adsorption at surfaces are studied through the reaction of four cyclohexanediamine isomerscis-1,2-, trans-1,2-, cis-1,4-, and trans-1,4-cyclo-hexanediamineat the Ge(100)-2 × 1 semiconductor surface. Using a combination of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, we find that all isomers primarily adsorb by reacting with both functional groups, either forming an N−Ge dative bond to the surface or undergoing N−H dissociation to form Ge−N and Ge−H ordinary covalent bonds. Among the four isomers, differences are observed in the relative amounts of dative bonded versus dissociated amines. Density functional theory calculations explain these results by showing that strain of the surface− adsorbate bonds and in the cyclohexane backbone of the adsorbate give rise to differences in the reaction energetics. In particular, trans-1,4-cyclohexanediamine is the only isomer that must adopt the twist-boat conformation to interact with the surface via both functional groups, and the energetic penalty of this requirement leads to its distinct product distribution in which N dative bonding is more prevalent than for the other three isomers studied.

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Section: Discussionsupporting

confidence: 85%

Adsorption of Structural and Stereoisomers of Cyclohexanediamine at the Ge(100)-2 × 1 Surface: Geometric Effects in Adsorption on a Semiconductor Surface

Wong

Bent

2013

J. Phys. Chem. C

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“…It also suggests that the reaction of anhydrides with vicinal diols in the cis-configuration is much faster than for the trans-configuration. This conclusion is in line with literature data for the esterification of cis-and transvicinal diols [42][43][44]. For instance, the esterification reaction of a mixture of cis-and trans-1-ethyl-1,2-cyclobutanediols with methylboronic acid (at RT) gave solely esters of the cisdiols, while the trans-diols remained unreacted [42].…”

Section: Esterification Of Dihydroxylated Jo Derivatives With Anhydrisupporting

confidence: 92%

Synthesis and properties of highly branched Jatropha curcas L. oil derivatives

Daniel

Ardiyanti

Schuur

et al. 2011

Euro J Lipid Sci & Tech

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The synthesis and properties of a number of novel branched Jatropha curcas L. oil (JO) derivatives containing vicinal di-ester units in the fatty acid chains are reported. Both the length (acetyl vs. hexanoyl) and the stereochemistry of the vicinal di-ester units (cis vs. trans) were varied. The compounds were prepared by two different synthetic approaches using catalytic chemistry. The first approach involves epoxidation of JO using a Sharpless epoxidation with methyltrioxorhenium as the catalyst to give epoxidized JO (1), followed by an esterification reaction with the corresponding anhydrides using ammonium-12-molybdophosphate (AMP) as catalyst to give trans-di-esters of JO (4a, 4b). The second approach is based on the dihydroxylation of JO using either the Prilezhaev method, resulting in trans-diols of JO (2), or the Upjohn method using osmium tetroxide as catalyst to give cis-diols of JO (3). In subsequent steps, the diols were esterified with acetic-or hexanoic anhydride using dimethylaminopyridine as catalyst to produce the corresponding cis-and trans-di-esters of JO (5a, 5b, 6). The best cold flow properties (lowest pour-and cloud point, crystallization and melting temperature) were obtained for JO with hexanoyl branches in a trans orientation (5b, pour point of À148C, melting point of À58C, and crystallization temperature of À258C) and these values are considerably better than for the JO source.Practical applications: Jatropha curcas L. oil (JO) is a toxic oil with potential applications not only as a green biodiesel but also as a feedstock for the oleochemical industry. The toxicity prohibits the use in food products but does not interfere with technical applications. Here we report studies on the synthesis of interesting JO derivatives (epoxidized, dihydroxylated, and branched compounds) that could be useful starting materials for a range of derivatives with a broad application perspective. The branched JO derivatives with vicinal di-ester units in the fatty acid chains have cold flow properties (pour-and cloud point, melting point and crystallization temperature) considerably better than the original JO. In addition, the oxidative stability was also improved significantly. These novel branched JO derivatives may have interesting applications as cold-flow improvers for biodiesel or as biolubricants.

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“…Several previous studies have discussed the relationship between the diol structures and their affinity to boronic acids [20,22,23]. The purpose of the current structure–affinity relationship study was to investigate the feasibility of BPBA for the derivatization of vicinal diols, particularly those with toxicological and environmental importance.…”

Section: Resultsmentioning

confidence: 99%

An approach based on liquid chromatography/electrospray ionization–mass spectrometry to detect diol metabolites as biomarkers of exposure to styrene and 1,3-butadiene

Shen

Zhang

Zeng

et al. 2009

Analytical Biochemistry

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Styrene and 1,3-butadiene are important intermediates used extensively in the plastics industry. They are metabolized mainly through cytochrome P450-mediated oxidation to the corresponding epoxides, which are subsequently converted to diols by epoxide hydrolase or through spontaneous hydration. The resulting styrene glycol and 3-butene-1,2-diol have been suggested as biomarkers of exposure to styrene and 1,3-butadiene, respectively. Unfortunately, poor ionization of the diols within electrospray mass spectrometers becomes an obstacle to the detection of the two diols by liquid chromatography/electrospray ionization–mass spectrometry (LC/ESI–MS). We developed an LC/ESI–MS approach to analyze styrene glycol and 3-butene-1,2-diol by means of derivatization with 2-bromopyridine-5-boronic acid (BPBA), which not only dramatically increases the sensitivity of diol detection but also facilitates the identification of the diols. The analytical approach developed was simple, quick, and convincing without the need for complicated chemical derivatization. To evaluate the feasibility of BPBA as a derivatizing reagent of diols, we investigated the impact of diol configuration on the affinity of a selection of diols to BPBA using the established LC/ESI–MS approach. We found that both cis and trans diols can be derivatized by BPBA. In conclusion, BPBA may be used as a general derivatizing reagent for the detection of vicinal diols by LC/MS.

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Stereoisomer-differentiating esterification of diols with methylboronic acid. A simple method for the separation of cis- and trans-1,2-diols

Cited by 8 publications

References 13 publications

Adsorption of Structural and Stereoisomers of Cyclohexanediamine at the Ge(100)-2 × 1 Surface: Geometric Effects in Adsorption on a Semiconductor Surface

Adsorption of Structural and Stereoisomers of Cyclohexanediamine at the Ge(100)-2 × 1 Surface: Geometric Effects in Adsorption on a Semiconductor Surface

Synthesis and properties of highly branched Jatropha curcas L. oil derivatives

An approach based on liquid chromatography/electrospray ionization–mass spectrometry to detect diol metabolites as biomarkers of exposure to styrene and 1,3-butadiene

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