Remarkably large remote-stereocenter-induced chromatographic differences: azulenyl 1,5-diols

Horgen, Dana A.; Klausmeyer, Kevin K.; Carson, Cody E.; Shen, Harry; Garner, Charles M.

doi:10.1016/j.tetlet.2013.10.134

Cited by 5 publications

(4 citation statements)

References 13 publications

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“…The synthesis of diols 1-6 has been recently reported [14]. These diols were formed as mixtures of diastereomers (RR/SS vs. RS/SR) that were easily separated by silica gel chromatography.…”

Section: Resultsmentioning

confidence: 99%

“…During studies of chromatographic separations of a series of racemic azulene 1,5-diols (1-6, Figure 1), we found [14] that the diastereomers were remarkably well separated (ΔR f ~ 0.22-0.46) on silica gel TLC. Subsequently, the chromatographic enantiomer separation using chiral High Performance Liquid Chromatography (HPLC) was undertaken partly to determine if the azulene ring was advantageous in cellulose-cased enantiomer separations.…”

Section: Open Accessmentioning

confidence: 99%

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Influence of the Azulene Ring on the Enantioseparation of 1,5-Diols

Horgen

Garner

2014

Chromatography

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The enantioseparation of a series of six azulene-centered 1,5-diol enantiomers was studied employing two cellulose-based chiral stationary phases under normal phase conditions (isopropanol/hexanes). The separations were generally quite good on Chiralcel-OD-H, with α values ranging from 1.2 to 8.4 (average 4.0) and resolution values of 0.4-8.3 (average 4.7). Only one of the six enantiomer pairs was not well resolved, but was well separated on Lux cellulose 2 (α 1.4, R s 8.7). It was observed that the enantioseparations of the RS/SR diastereomers (ave α = 7.8, R s = 8.2) were dramatically better than that of the corresponding RR/SS diastereomers (ave α = 2.1, R s = 3.0) on Chiralcel-OD-H. The better-resolved diastereomer pairs correspond to the more strongly retained diastereomers on silica gel. The enantiomers of two benzene 1,5-diols were much more poorly separated on both stationary phases, suggesting that the unusual polarity of the azulene ring enhances critical interactions with these phases.

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“…The synthesis of diols 1-6 has been recently reported [14]. These diols were formed as mixtures of diastereomers (RR/SS vs. RS/SR) that were easily separated by silica gel chromatography.…”

Section: Resultsmentioning

confidence: 99%

Section: Open Accessmentioning

confidence: 99%

Influence of the Azulene Ring on the Enantioseparation of 1,5-Diols

Horgen

Garner

2014

Chromatography

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“…Alternatively, 4b has also been synthesized by hydrogenation of cyclopentane-1,3-dione ( 4 ) using stoichiometric reducing agents 20 and with the homogeneous ruthenium Shvo catalyst. 21 To the best of our knowledge, the hydrogenation of 4 to 4b using supported metal catalysts has surprisingly not been explored yet, albeit procedures employing Raney Nickel onto alkyl-substituted variants of 4 have been reported. 22 Interestingly, an incidental discovery by Noyori et al ( 23 ) revealed that 3 can be isomerized into 4 in the presence of a Rh-phosphine catalyst, which denotes a potentially sustainable route for producing 4 .…”

Section: Introductionmentioning

confidence: 99%

“…Alternatively, 4b has also been synthesized by hydrogenation of cyclopentane-1,3-dione ( 4 ) using stoichiometric reducing agents and with the homogeneous ruthenium Shvo catalyst . To the best of our knowledge, the hydrogenation of 4 to 4b using supported metal catalysts has surprisingly not been explored yet, albeit procedures employing Raney Nickel onto alkyl-substituted variants of 4 have been reported .…”

Section: Introductionmentioning

confidence: 99%

Hydrogenation of Cyclic 1,3-Diones to Their 1,3-Diols Using Heterogeneous Catalysts: Toward a Facile, Robust, Scalable, and Potentially Bio-Based Route

Slagmaat

Verzijl²,

Quaedflieg³

et al. 2021

ACS Omega

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Cyclopentane-1,3-diol ( 4b ) has gained renewed attention as a potential building block for polymers and fuels because its synthesis from hemicellulose-derived 4-hydroxycyclopent-2-enone ( 3 ) was recently disclosed. However, cyclopentane-1,3-dione ( 4 ), which is a constitutional isomer of 3 , possesses a higher chemical stability and can therefore afford higher carbon mass balances and higher yields of 4b in the hydrogenation reaction under more concentrated conditions. In this work, the hydrogenation of 4 into 4b over a commercial Ru/C catalyst was systematically investigated on a bench scale through kinetic studies and variation of reaction conditions. Herein, the temperature, H 2 -pressure, and the solvent choice were found to have significant effects on the reaction rate and suppression of undesired dehydration of 4 . The cis – trans ratio of 4b is naturally generated as 7:3 in these reactions. However, at elevated reaction temperatures, 4b epimerizes, yielding more trans products. This effect was also studied and rationalized from a thermodynamic perspective using DFT. The combined optimized reaction conditions provided 78% yield for 4b , and successful applications to 8-fold scaled up reactions (40 g) and a substrate scope of several 1,3-diones demonstrate the general applicability of this catalytic approach.

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Nucleophilic Additions of Perfluoroalkyl Groups

Beier

Zibinsky²,

Prakash

2016

Organic Reactions

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The trifluoromethyl and perfluoroalkyl functional groups possess significant thermal, chemical, and metabolic stability, as well as high lipophilicity and electronegativity. These physicochemical properties render fluorinated carbon residues indispensable in diverse applications, such as agrochemistry, drug design, and material chemistry. The generation and properties of nucleophilic perfluoroalkyl reagents as well as the scope and limitations of their additions to various electrophilic partners is described in this chapter.

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Remarkably large remote-stereocenter-induced chromatographic differences: azulenyl 1,5-diols

Cited by 5 publications

References 13 publications

Influence of the Azulene Ring on the Enantioseparation of 1,5-Diols

Influence of the Azulene Ring on the Enantioseparation of 1,5-Diols

Hydrogenation of Cyclic 1,3-Diones to Their 1,3-Diols Using Heterogeneous Catalysts: Toward a Facile, Robust, Scalable, and Potentially Bio-Based Route

Nucleophilic Additions of Perfluoroalkyl Groups

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