51789-95-8Relevant academic research and scientific papers
Method for preparing single-configuration C-2-position-monosubstituted norbornene derivative
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, (2021/07/01)
The invention discloses a method for preparing a single-configuration C-2-position-monosubstituted norbornene derivative. The method comprises the following steps of: firstly, preparing exo-isomer enriched exo-isomer mixed 5-norbornene-2-carboxylic ester by taking commercial exo-isomer/endoisomer mixed 5-norbornene-2-carboxylic acid and large-steric-hindrance monohydric alcohol as raw materials; separating 5-norbornene-2-carboxylate with a single configuration through common column chromatography separation or fractionation; and finally, preparing the C-2-position-monosubstituted norbornene derivative with the single configuration from the separated 5-norbornene-2-carboxylate with the single configuration. The raw materials used in the invention are easy to obtain, the preparation process is simple, and the C-2-position-monosubstituted norbornene derivative with high purity (greater than 98%) and single configuration can be obtained.
Borenium ionic liquids as catalysts for Diels-Alder reaction: Tuneable Lewis superacids for catalytic applications
Matuszek,Coffie,Chrobok,Swad?ba-Kwa?ny
, p. 1045 - 1049 (2017/08/15)
Ionic liquids based on the tricoordinate borenium cation were used for the first time as Lewis acid catalysts for a model Diels-Alder reaction. The conversion of the dienophile was successfully correlated with the Gutmann acceptor number values of the ionic liquids. Borenium ionic liquids exceeded the performance of catalysts reported in the literature.
Synthesis and computational analysis of conformationally restricted [3.2.2]- and [3.2.1]-3-azabicyclic diamines
Tummalapalli, Sreedhar Reddy,Bhat, Rohit,Waitt, Craig,Eshuis, Henk,Rotella, David P.
, p. 4087 - 4089 (2017/10/06)
Conformational restriction is a useful approach for ligand design in organic and medicinal chemistry. This manuscript reports the facile synthesis and in silico conformational analysis of two new diastereomeric [3.2.2]-3-azabicyclic, two new [3.2.1]-3-aza-8-oxy-bicyclic and one new [3.2.1]-3-azabicyclic diamine scaffolds. A conformational analysis of these structures along with calculation of carbon–carbon/carbon–nitrogen bond angles was carried out and compared to those in the flexible 1,3-diaminopropane template upon which they were based. It is of particular importance that these scaffolds have bond lengths and angles that can overlap with low energy conformers of the flexible diamine. Such information is useful for ligand design in organic chemistry and for development of structure activity relationships and in silico screening in medicinal chemistry.
Liquid coordination complexes of Lewis acidic metal chlorides: Lewis acidity and insights into speciation
Hogg, James M.,Brown, Lucy C.,Matuszek, Karolina,Latos, Piotr,Chrobok, Anna,Swad?ba-Kwa?ny, Ma?gorzata
, p. 11561 - 11574 (2017/09/18)
Coordination complexes of Lewis acidic metal chlorides AlCl3, GaCl3, InCl3, SbCl3, SnCl4, SnCl2, ZnCl2 and TiCl4 with trioctylphosphine (P888) and trioctylphosphine oxide (P888O) were synthesised. All compounds formed liquid coordination complexes (LCCs) at ambient temperature, although decomposition via a redox mechanism was detected in some cases. The Lewis acidity of the metal chlorides (measured in 1,2-dichloroethane solutions) and the LCCs (measured neat) was quantified by using the Gutmann acceptor number (AN) approach. In general, LCCs were equally or more Lewis acidic than the corresponding metal chlorides. The AN values were compared with the catalytic activity of selected LCCs in a model Diels-Alder reaction. Insight into speciation of LCCs was gained using multinuclear NMR spectroscopy, revealing that most LCCs comprised charge-neutral complexes rather than ionic ones. The relationship between the speciation, Lewis acidity (AN scale) and catalytic activity is discussed in detail. This approach reveals several new, promising catalytic systems, such as P888O-InCl3, with Lewis acidity enhanced compared to chloroindate ionic liquids, and P888O-TiCl4, with hydrolytic stability enhanced with respect to neat TiCl4.
Design and Development of Highly Potent HIV-1 Protease Inhibitors with a Crown-Like Oxotricyclic Core as the P2-Ligand To Combat Multidrug-Resistant HIV Variants
Ghosh, Arun K.,Rao, Kalapala Venkateswara,Nyalapatla, Prasanth R.,Osswald, Heather L.,Martyr, Cuthbert D.,Aoki, Manabu,Hayashi, Hironori,Agniswamy, Johnson,Wang, Yuan-Fang,Bulut, Haydar,Das, Debananda,Weber, Irene T.,Mitsuya, Hiroaki
, p. 4267 - 4278 (2017/06/05)
Design, synthesis, and evaluation of a new class of exceptionally potent HIV-1 protease inhibitors are reported. Inhibitor 5 displayed superior antiviral activity and drug-resistance profiles. In fact, this inhibitor showed several orders of magnitude improved antiviral activity over the FDA approved drug darunavir. This inhibitor incorporates an unprecedented 6-5-5 ring-fused crown-like tetrahydropyranofuran as the P2 ligand and an aminobenzothiazole as the P2′ ligand with the (R)-hydroxyethylsulfonamide isostere. The crown-like P2 ligand for this inhibitor has been synthesized efficiently in an optically active form using a chiral Diels-Alder catalyst providing a key intermediate in high enantiomeric purity. Two high resolution X-ray structures of inhibitor-bound HIV-1 protease revealed extensive interactions with the backbone atoms of HIV-1 protease and provided molecular insight into the binding properties of these new inhibitors.
Modulation of reactivities of dienophiles for diels-alder reactions via complexation of α,β-unsaturated chelating amides
Sterk, Markus,Bannwarth, Willi
, p. 287 - 307 (2015/03/30)
We describe the modulation of reactivities of dienophiles for Diels-Alder reactions via a new principle based on chelating amides positioned adjacent to their C-C bond. It is demonstrated for modified acrylic acid derivatives and related dienophiles with three different chelating entities. Complexation of the chelators leads to an intensified electron-withdrawing effect leading to an enhancement of reactivity in Diels-Alder reactions depending on the complexed metal ion. The application of this new approach might be extended to other reactions with reacting entities adjacent to chelating amides.
Diels-alder reaction in air-and moisture-stable zinc-containing ionic liquids
Sun, I.-Wen,Wu, Shin-Yi,Su, Chia-Hao,Shu, Yu-Lin,Wu, Pei-Lin
, p. 367 - 370 (2015/02/05)
Diels-Alder reactions in a number of air- and moisture-stable dialkylimidazolium halide-ZnCl2 ionic liquids are reported. High yields and high endo selectivities have been observed. The ionic liquids could then be recyclable without loss of reactivity.
From norbornane-based nucleotide analogs locked in South conformation to novel inhibitors of feline herpes virus
Dejmek, Milan,Hrebabecky, Hubert,Sala, Michal,Dracinsky, Martin,Prochazkova, Eliska,Leyssen, Pieter,Neyts, Johan,Balzarini, Jan,Nencka, Radim
supporting information, p. 2974 - 2983 (2014/05/20)
A synthetic route toward a series of unique cyclic nucleoside phosphonates locked in South conformation is described. The desired conformation is stabilized by a substitution of the sugar moiety by bicyclo[2.2.1]heptane (norbornane) bearing a purine or pyrimidine nucleobase in the bridgehead position. Although the final phosphonate derivatives are devoid of any significant antiviral activity probably due to the unfavorable conformational properties, several intermediates and their analogs exhibit surprising activity against feline herpes virus. Since these compounds do not possess an appropriate hydroxymethyl function allowing phosphorylation and subsequent incorporation into the polynucleotide chain, it seems to be likely that these compounds act by a novel unknown mechanism of action and may represent a new possible alternative for nucleoside and nucleotide therapeutics of this widely spread feline infection. A number of derivatives exerted also a significant antiviral activity against Coxsackievirus B3 and B4.
Stereoselectivity of the Diels-Alder reaction in ionic liquids with cyano moieties: Effect of the charge delocalization of anions on the relation of solvent-solvent and solute-solvent interactions
Nobuoka, Kaoru,Kitaoka, Satoshi,Yanagisako, Atsuki,Maki, Yusuke,Harran, Thomas,Ishikawa, Yuichi
, p. 19632 - 19638 (2013/10/22)
In imidazolium ILs, the negative charge delocalization induced by multiple electron-withdrawing cyano groups can be useful in regulating the microscopic environment in imidazolium ILs. For this anion design, the ion-counterion (solvent-solvent) interaction is weakened, the ion-solute (solvent-solute) interaction is facilitated, and the bulkiness of the anion is increased. The electrostatic interaction with the cation has a strong effect on the ion states of the ILs and the stereoselectivity in the Diels-Alder reaction. These regulation methods potentially have wide applications to various useful reactions using ILs.
LiAlH4-induced reductive dephosphonylation of αα-dialkyl triethyl β-phosphonyl esters: Mechanistic study and synthetic application
Zhu, Jia-Liang,Bau, Jr-Sheng,Shih, You-Cheng
experimental part, p. 863 - 866 (2012/05/20)
Treatment of αα-dialkyl triethyl β-phosphonyl esters with LiAlHin CHlTHF caused the one-pot dephosphonylation and reduction to yield the corresponding primary alcohols bearing a controllable β secondary carbon center. Mechanistic study has revealed that the LiAlHinduced dephosphonylation should occur first with the assistance of the carboxylate group, and the hydrogen source of the resultant new C-H bond is LiAlH. Georg Thieme Verlag Stuttgart . New York.
