Boron and Silicon-Substituted 1,3-Dienes and Dienophiles and Their Use in Diels-Alder Reactions

Welker, Mark E.

doi:10.3390/molecules25163740

Cited by 16 publications

(6 citation statements)

References 44 publications

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“…50 The geometric structure of the silone ring is very similar to those of the previously reported silone derivatives that through [4+2] Diels-Alder reactions form new Si-C bonds upon ring closure. 51,52 As shown in Table 1 and Fig. S5, S6 (ESI †), it is apparent that the prediction of 1-ethynyl-1H-silole vibration frequencies and intensities show excellent agreement with the experimental and 866.3 cm À1 respectively.…”

Section: Resultssupporting

confidence: 57%

Formation of 1-ethynyl-1H-silole from the reaction of silicon atoms with benzene: matrix infrared spectroscopy and quantum chemical calculations

et al. 2022

Phys. Chem. Chem. Phys.

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Section: Resultssupporting

confidence: 57%

Formation of 1-ethynyl-1H-silole from the reaction of silicon atoms with benzene: matrix infrared spectroscopy and quantum chemical calculations

et al. 2022

Phys. Chem. Chem. Phys.

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“…Herein, silane was chosen as the activation group due to its ease of removal and ability to circumvent nucleophilic addition. 57 Unlike the esteryl group that activates the alkyne through the electron-withdrawing conjugation, the silanyl group uses the empty d orbitals to accommodate the electrons of the alkynyl (Figure 7A). Accordingly, two silicane dienophiles were designed, (R)-5-(trimethylsilyl)pent-1-en-4-yn-3-ol ( 5) and (R)-7-(trimethylsilyl)hepta-1-en-4,6-diyn-3-ol (7) as the dienophile, and additional DFT computational study was performed to ascertain their regioselectivity in the proposed Diels−Alder/ retro-Diels−Alder reaction.…”

Section: Acs Centralmentioning

confidence: 99%

Discovery of a Potent Antiosteoporotic Drug Molecular Scaffold Derived from Angelica sinensis and Its Bioinspired Total Synthesis

Zou,

Qiu,

et al. 2024

ACS Cent. Sci.

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Angelica sinensis, commonly known as Dong Quai in Europe and America and as Dang-gui in China, is a medicinal plant widely utilized for the prevention and treatment of osteoporosis. In this study, we report the discovery of a new category of phthalide from Angelica sinensis, namely falcarinphthalides A and B (1 and 2), which contains two fragments, (3R,8S)-falcarindiol ( 3) and (Z)ligustilide (4). Falcarinphthalides A and B (1 and 2) represent two unprecedented carbon skeletons of phthalide in natural products, and their antiosteoporotic activities were evaluated. The structures of 1 and 2, including their absolute configurations, were established using extensive analysis of NMR spectra, chemical derivatization, and ECD/VCD calculations. Based on LC-HR-ESI-MS analysis and DFT calculations, a production mechanism for 1 and 2 involving enzymecatalyzed Diels−Alder/retro-Diels−Alder reactions was proposed. Falcarinphthalide A (1), the most promising lead compound, exhibits potent in vitro antiosteoporotic activity by inhibiting NF-κB and c-Fos signaling-mediated osteoclastogenesis. Moreover, the bioinspired gram-scale total synthesis of 1, guided by intensive DFT study, has paved the way for further biological investigation. The discovery and gram-scale total synthesis of falcarinphthalide A (1) provide a compelling lead compound and a novel molecular scaffold for treating osteoporosis and other metabolic bone diseases.

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“…The extent to which they alter reaction rate is dependent on the second reacting species as well e.g., methyl substituent on diene showed different effect on the reaction barrier with two different dienophiles [26]. Silicon and boron substituted dienes and dienophiles have been studied heavily due to their ease of handling and synthesis [27]. Good understanding of reaction mechanisms is crucial in improving the rout for the synthesis of industrially, medicinally and agriculturally useful products [28,29].…”

Section: Introductionmentioning

confidence: 99%

Quantum Mechanical Modeling Unveil the Effect of Substitutions on the Activation Barriers of the Diels-Alder Reactions of an Antiviral Compound 7H-Benzo[a]phenalene

Rehman

Mansha

Zahid

et al. 2021

Preprint

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Density functional theory has been utilized for exploring the mechanism of Diels-Alder reaction between 7H-benzo[a]phenalene and maleic anhydride. 7H-Benzo[a]phenalene is an antiviral compound and information available about its cycloaddition reactions with possible reaction path and mechanism is scarce. In order to work on the synthesis of its further potential derivatives, the mechanism of its reaction with all aspects should be well understood. Two novel intermediates involved in this reaction have been reported. Diels-Alder reaction of maleic anhydride has found many applications in the synthesis of wide range of useful products. The major concern of this work is to evaluate the consequences of introducing electron donating and electron withdrawing substituents on the reactivity of maleic anhydride towards 7H-benzo[a]phenalene. Thermodynamic parameters, activation parameters, energies of frontier orbitals, global reactivity indices and global electron density transfer (GEDT) have been determined for all the reactions. Fukui functions are computed for each reactant in order to identify the most reactive sites. All the reactions have been found to proceed via normal electron demand having polar nature. The substituents with opposite electronic properties were expected to affect the reactivity of dienophile in an inverse manner, however, the results are not according to this assumption. Rather, both kinds of substituents increased the activation barrier of the reaction. This behavior has been explained in the light of various parameters such as the stability of reacting species, gap of frontier molecular orbitals etc. Experimental studies reported previously are in agreement with these results.

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Boron and Silicon-Substituted 1,3-Dienes and Dienophiles and Their Use in Diels-Alder Reactions

Cited by 16 publications

References 44 publications

Formation of 1-ethynyl-1H-silole from the reaction of silicon atoms with benzene: matrix infrared spectroscopy and quantum chemical calculations

Formation of 1-ethynyl-1H-silole from the reaction of silicon atoms with benzene: matrix infrared spectroscopy and quantum chemical calculations

Discovery of a Potent Antiosteoporotic Drug Molecular Scaffold Derived from Angelica sinensis and Its Bioinspired Total Synthesis

Quantum Mechanical Modeling Unveil the Effect of Substitutions on the Activation Barriers of the Diels-Alder Reactions of an Antiviral Compound 7H-Benzo[a]phenalene

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