69819-61-0Relevant academic research and scientific papers
Hydrogen-Bond Catalysis of Imine Exchange in Dynamic Covalent Systems
Schaufelberger, Fredrik,Seigel, Karolina,Ramstr?m, Olof
supporting information, p. 15581 - 15588 (2020/10/02)
The reversibility of imine bonds has been exploited to great effect in the field of dynamic covalent chemistry, with applications such as preparation of functional systems, dynamic materials, molecular machines, and covalent organic frameworks. However, acid catalysis is commonly needed for efficient equilibration of imine mixtures. Herein, it is demonstrated that hydrogen bond donors such as thioureas and squaramides can catalyze the equilibration of dynamic imine systems under unprecedentedly mild conditions. Catalysis occurs in a range of solvents and in the presence of many sensitive additives, showing moderate to good rate accelerations for both imine metathesis and transimination with amines, hydrazines, and hydroxylamines. Furthermore, the catalyst proved simple to immobilize, introducing both reusability and extended control of the equilibration process.
Synthesis and Cytotoxicity of Octahydroepoxyisoindole-7-carboxylic Acids and Norcantharidin–Amide Hybrids as Norcantharidin Analogues
Hizartzidis, Lacey,Gilbert, Jayne,Gordon, Christopher P.,Sakoff, Jennette A.,McCluskey, Adam
supporting information, p. 1152 - 1161 (2019/05/24)
Octahydroepoxyisoindole analogues of norcantharidin were accessed through a Diels–Alder reaction of an amine-substituted furan with maleic anhydride and subsequent reduction of the bicyclo[2.2.1]heptene olefin. Despite retention of the carboxylate and the ether bridgehead known to impart cytotoxic activity to norcantharidin, none of these analogues displayed notable cytotoxicity against the 11 cell lines examined: HT29 (colon), MCF-7 (breast), A2780 (ovarian), H460 (lung), A431 (skin), Du145 (prostate), BE2-C (neuroblastoma), SJ-G2 and U87 (glioblastoma), MIA (pancreatic), and SMA (spontaneous murine astrocytoma). The incorporation of an amino-substituted system post-synthesis of norcantharidin afforded facile access to 14 acid/amide-substituted norcantharidin analogues. Of these, only four displayed sufficient activity at the initial 25 μm compound screening dose to warrant full evaluation of growth inhibition. Common to these analogues was the presence of a 4-biphenyl moiety, and in particular 3-(2-(furan-2-ylmethyl)-3-(4-biphenylamino)-3-oxopropylcarbamoyl)-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (13 c) and 3-(2-(pyrrole-2-ylmethyl)-3-(4-biphenylamino)-3-oxopropylcarbamoyl)-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (24) displayed high levels of cytotoxicity, returning GI50 values of 15 nm (HT29) to 2.9 μm (U87) and 17 nm (SMA) to 2.8 μm (U87), respectively. These are the most cytotoxic norcantharidin analogues reported to date.
Ruthenium-catalyzed N-alkylation of amines with alcohols under mild conditions using the borrowing hydrogen methodology
Enyong, Arrey B.,Moasser, Bahram
, p. 7553 - 7563 (2014/09/17)
Using a simple amino amide ligand, ruthenium-catalyzed one-pot alkylation of primary and secondary amines with simple alcohols was carried out under a wide range of conditions. Using the alcohol as solvent, alkylation was achieved under mild conditions, even as low as room temperature. Reactions occurred with high conversion and selectivity in many cases. Reactions can also be carried out at high temperatures in organic solvent with high selectivity using stoichiometric amounts of the alcohol.
Intra-molecular Diels-Alder reactions of citraconamic acids from furfurylamines and citraconic anhydride: Effects of substitution in the furan ring on regioselectivity
Murali, Rajappa,Surya Prakash Rao,Scheeren, Hans W
, p. 3165 - 3174 (2007/10/03)
Regioselectivity in the intra-molecular Diels-Alder (IMDA) reaction of furfurylcitraconamic acids derived from N-benzylfurfurylamines and citraconic anhydride can be controlled by substituents located in the furan ring and by reaction conditions. Reactions conducted under kinetic conditions resulted in cycloaddition products having methyl and aminomethylene substituent in 1,3-relationship whereas under thermodynamic conditions, excepting in the case of the 3-methylsulfanyl group, the products rearranged to more stable cycloadducts in which the substituents are in 1,2-relationship. Product formation can be explained on the basis of frontier orbital interactions and steric considerations.
Reductive Amination of 2-Furaldehyde with Cyclohexylamine over Palladium Catalysts
Klyuev, M. V.,Abdullaev, M. G.,Nasibulin, A. A.
, p. 378 - 379 (2007/10/03)
Reductive amination of 2-furaldehyde with cyclohexylamine over Pd/C, as also over AN-1 and AV-17-8 palladium-containing anion exchangers, under mild conditions (20-60 deg C, H2 at 98-103 kPa, organic solvents) results in formation of N-tetrahydrofurfurylcyclohexylamine in high yield.Metal-polymer catalysts ensure lower reaction rates but higher selectivity than Pd/C.They are also more stable.In all cases the reaction rate is linearly related to the dielectric constants of the solvents.
