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Kosuke Yamamoto Keisuke Miyamoto Mizuki Ueno Yuki Takemoto Masami Kuriyama Osamu Onomura 《Molecules (Basel, Switzerland)》2022,27(24)
Glycerol is the main side product in the biodiesel manufacturing process, and the development of glycerol valorization methods would indirectly contribute the sustainable biodiesel production and decarbonization. Transformation of glycerol to optically active C3 units would be one of the attractive routes for glycerol valorization. We herein present the asymmetric sulfonylative desymmetrization of glycerol by using a CuCN/(R,R)-PhBOX catalyst system to provide an optically active monosulfonylated glycerol in high efficiency. A high degree of enantioselectivity was achieved with a commercially available chiral ligand and an inexpensive carbonate base. The optically active monosulfonylated glycerol was successfully transformed into a C3 unit attached with differentially protected three hydroxy moieties. In addition, the synthetic utility of the present reaction was also demonstrated by the transformation of the monosulfonylated glycerol into an optically active synthetic ceramide, sphingolipid E. 相似文献
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Ren-Zhe Li Hua Tang Dr. Ke R. Yang Li-Qiang Wan Xia Zhang Jie Liu Zhengyan Fu Prof. Dawen Niu 《Angewandte Chemie (International ed. in English)》2017,56(25):7213-7217
A copper/borinic acid dual catalytic reaction enabled the enantioselective propargylation of aliphatic polyols. Readily available reagents and catalysts were used in this transformation, which displayed good to excellent chemo- and stereoselectivity for a broad array of substrates. The method was also applicable to the desymmetrization of meso 1,2-diols to furnish products with three stereogenic centers and a terminal alkyne group in one operation. 相似文献
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Ming Yang Dr. Yu‐Ming Zhao Dr. Shu‐Yu Zhang Prof. Dr. Yong‐Qiang Tu Prof. Dr. Fu‐Min Zhang 《化学:亚洲杂志》2011,6(6):1344-1347
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Highly Enantioselective Construction of Tricyclic Derivatives by the Desymmetrization of Cyclohexadienones 下载免费PDF全文
Sandra del Pozo Dr. Alejandro Parra Dr. Sergio Díaz‐Tendero Dr. Rubén Mas‐Ballesté Dr. Silvia Cabrera Dr. José Alemán 《Angewandte Chemie (International ed. in English)》2014,53(31):8184-8189
The asymmetric synthesis of tricyclic compounds by the desymmetrization of cyclohexadienones is presented. The reaction tolerated a large variety of substituents at different positions of the cyclohexadienone, and heterocyclic rings of different sizes were accessible. Density functional theory calculations showed that the reaction proceeds through an asynchronous [4+2] cycloaddition. 相似文献
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Daniel Sälinger Dipl.‐Chem. Reinhard Brückner Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(27):6688-6703
Choosy organomagnesium : Prochiral bis(bromoaryl)alcohols were desymmetrized by treatment with iPr2Mg and an enantiopure Li salt. The resulting arylmagnesium intermediate was trapped with electrophiles. Protonolysis and two follow‐up reactions provided the antihistaminic and anticholinergic drug (R)‐orphenadrine (see scheme).
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Fujioka H Fujita T Kotoku N Ohba Y Nagatomi Y Hiramatsu A Kita Y 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(21):5386-5397
A new chiral auxiliary, a 3-endo-phenyl norbornene aldehyde derivative, which is a crystalline, very stable, and easily handled, was developed for the desymmetrization of meso-1,3- and meso-1,4-diols. The key step of the method, an intramolecular bromoetherification, proceeded in a highly diastereoselective manner. A four-step sequence, 1) acetalization, 2) intramolecular bromoetherification followed by acid hydrolysis, 3) protection of the alcohol, and 4) retrobromoetherification, transformed the meso-diols into optically active derivatives. The 3-endo-phenyl norbornene aldehyde derivative was simultaneously reformed and could be used repeatedly. This is the first chemical example of a single auxiliary that is applicable for highly enantioselective desymmetrization of meso-1,3- and meso-1,4-diols; to the best of our knowledge, this is the best chemical method available for the desymmetrization of meso-1,4-diols. 相似文献
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To determine optical purities of four aromatic 1,2-diol enantiomers synthesized by a Sharpless asymmetric dihydroxylation
(AD) reaction of olefins, a simple and reliable separation method was achieved with high resolution (R
s > 2.2) by capillary zone electrophoresis (CZE) using hydroxypropyl-β-cyclodextrin (HP-β-CD) as chiral selector and borate
combined with methanol additive as background buffer. Furthermore, the developed CZE method was successfully applied to the
determination of enantiomeric excess of the tested enantiomers. RSD values of migration time and peak area fell within 1.0
and 3.8%, respectively. This method allowed for the determination of ee (%) values of targeted isomers as high as 99.6%. Impurities
of undesired isomers could be detected at levels as low as 0.2% in the presence of the targeted isomers. 相似文献
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P. Koparir M. Karaarslan C. Orek M. Koparir 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):864-870
Abstract (1R,2R)-1,2-bis[5-(arylideneamino)-1,3,4-thiadiazol-2-yl]ethane-1,2-diol (2a–d) were synthesized by using appropriate aldehydes and (1R,2R)-1,2-bis(5-amino-1,3,4-thiadiazol-2-yl)ethane-1,2-diol (1) as a starting compound. Then, the phosphinic acid component (3a–d) were obtained from (2a–d) and hypophosporus acid. In addition, the structures of the novel chiral compounds (2a–d) and (3a–d) were confirmed by elemental analyses, IR, 1H-NMR, 13C-NMR, and 31P-NMR spectra. 1H NMR and 13C NMR spectra for 1, 2a, and 3a (Figures S1–S6) are available online in the Supplemental Materials. 相似文献
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Guanlin Li Ling Zhao Yicong Luo Youbin Peng Kai Xu Dr. Xiaohong Huo Prof. Dr. Wanbin Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(24):e202200273
Asymmetric desymmetrization has been demonstrated to be a powerful strategy for building stereocenters in asymmetric synthesis. Herein, a Pd/Cu catalyzed asymmetric desymmetrization reaction with a simple geminal dicarboxylate is reported. A wide scope of imino esters bearing an aryl or heteroaromatic group were compatible with this bimetallic catalytic system. The reactions proceeded smoothly, giving the desired products in good yields with high to excellent regio-, diastereo-, and enantioselectivity (up to 20 : 1 branched:linear, >20 : 1 dr, >99 % ee). Notably, the reaction favored branched selectivity, which is unusual for the Pd-catalyzed allylic alkylation reaction. In addition, the standard product could be easily transformed to other valuable molecules such as chiral allylic alcohols, carbamates, and organic boron compounds. Furthermore, DFT calculations were conducted to explain the origin of the branched selectivity. 相似文献
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Saravanan Peruncheralathan Dr. Henrik Teller Christoph Schneider Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4849-4852
It's as simple as that : An in situ prepared chiral catalyst from the commercially available compounds Ti(OiPr)4 and (R)‐binol catalyzes the highly enantioselective ring‐opening of meso‐aziridines 1 with anilines 2 and furnishes valuable chiral 1,2‐diamines 3 in high yields and up to 99 % ee.(R)‐binol=(R)‐2,2′‐dihydroxy‐1,1′‐binaphthyl.
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Masakazu Tanaka 《Tetrahedron》2004,60(10):2271-2281
Asymmetric ring cleavage reaction of meso-carbobicyclic ketones by a combination of benzaldehyde, chiral cycloalkane-1,2-diol, and Lewis acid gave optically active styrenyl esters of 26-69% ee in moderate yield. The ring cleavage reaction could be applied to the construction of adjacent chiral quaternary carbons, and also to the formal synthesis of natural alkaloid (−)-alloyohimbane. 相似文献
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Akai S Tsujino T Fukuda N Iio K Takeda Y Kawaguchi K Naka T Higuchi K Akiyama E Fujioka H Kita Y 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(21):6286-6297
The asymmetric total synthesis of the potent antitumor antibiotic fredericamycin A ((S)-1) was achieved by the intramolecular [4+2] cycloaddition of the silylene-protected styrene derivative (S)-7 followed by the aromatic Pummerer-type reaction of the sulfoxide (S)-5. Although we had already succeeded in the total synthesis of racemic 1 by the same approach, synthesis of its asymmetric version was more complicated than we had expected due to the difficulties involved in constructing the quaternary carbon center and the tendency of this center to undergo facile racemization. Racemization of this center during the installation of the acetylene moiety on the dione (R)-8 was the most serious aspect. Systematic studies of its DE-ring analogue (R)-25 revealed that racemization of the quaternary carbon center proceeded by a retro-aldol-aldol reaction of the initial adduct, (1R)-39 a-Li, and that the degree of racemization was dependent on the reaction temperature. The racemization process could be completely depressed by keeping the reaction temperature at -78 degrees C. The construction of the stereogenic quaternary carbon center was achieved by the lipase-catalyzed desymmetrization of the prochiral 1,3-diol 9 a bearing the DEF-ring moiety. These studies enabled us to attain the asymmetric total synthesis of (S)-1 while completely retaining the chiral integrity created by the enzymatic reactions. 相似文献