21 research outputs found
The polymorphism of 2-benzoyl-N,N-diethylbenzamide
The crystal structures of two new polymorphs of 2-benzoyl-N,N-diethylbenzamide were obtained after recrystallization trials with different solvents. The new forms II and III were monoclinic and crystallized in the same space group with similar a, b and c lengths but different β angles. The forms had no conformation differences within themselves; however, the long-range packing (> two unit cells) was not isostructural. In comparison with the previously published crystal structure, form I, different conformations and packing arrangements were observed. The new form II was thermally characterized and stable at room temperature, when heated up to its melting point and when cooled to −170 °C. Additionally, once form II was re-heated, a fourth form is observed after a phase transition from the monoclinic to the orthorhombic crystal systems, form IV
Direct aerobic oxidation of alcohols into esters catalyzed by carbon nanotube–gold nanohybrids
International audienceGold nanoparticles supported on carbon nanotubes were shown to efficiently catalyze the oxidation of alcohols to methyl esters under mild and selective reaction conditions. The reaction works with low catalyst loadings and the nanohybrid could be readily recycled and reused
Triphenylbismuth dichloride-mediated conversion of thioamides to nitriles
International audienc
Catalytic Dehydrosulfurization of Thioamides to Nitriles by Gold Nanoparticles Supported on Carbon Nanotubes
International audienceA gold‐carbon nanotube nanohybrid was shown to act as an efficient heterogeneous catalyst in the smooth and selective conversion of thioamides to the corresponding nitriles. The reaction was performed under mild conditions (room temperature, atmospheric pressure of oxygen) using only a gold loading of 0.35 mol %. Substituted aromatic or aliphatic nitriles were produced in very good to excellent yields and the catalyst could be easily recycled and reused over several consecutive cycles with no loss in dehydrosulfurization performances
Synthesis of Fused Bromofurans via Mg-Mediated Dibromocyclopropanation of Cycloalkanone-Derived Chalcones and Cloke–Wilson Rearrangement
A convenient two-step sequence for the conversion of
alkylidenecycloalkanones
to bromofurans is reported. The steps involve Mg-mediated diastereoselective
dibromocyclopropanation of alkylidenecycloalkanone followed by acidic
alumina-mediated regioselective ring expansion of the cyclopropyl
ketone. The scope of the reaction was investigated using alkylidenecycloalkanones
derived from tetralone, indanone, and benzosuberone to afford 2-aryl-3-bromofurans
fused to various benzocycloalkanes. Representative examples of stereoconvergent
dibromocyclopropanation and total aromatization of the furobenzocycloalkane
are also reported
Synthesis of Fused Bromofurans via Mg-Mediated Dibromocyclopropanation of Cycloalkanone-Derived Chalcones and Cloke–Wilson Rearrangement
A convenient two-step sequence for the conversion of
alkylidenecycloalkanones
to bromofurans is reported. The steps involve Mg-mediated diastereoselective
dibromocyclopropanation of alkylidenecycloalkanone followed by acidic
alumina-mediated regioselective ring expansion of the cyclopropyl
ketone. The scope of the reaction was investigated using alkylidenecycloalkanones
derived from tetralone, indanone, and benzosuberone to afford 2-aryl-3-bromofurans
fused to various benzocycloalkanes. Representative examples of stereoconvergent
dibromocyclopropanation and total aromatization of the furobenzocycloalkane
are also reported
Synthesis of Fused Bromofurans via Mg-Mediated Dibromocyclopropanation of Cycloalkanone-Derived Chalcones and Cloke–Wilson Rearrangement
A convenient two-step sequence for the conversion of
alkylidenecycloalkanones
to bromofurans is reported. The steps involve Mg-mediated diastereoselective
dibromocyclopropanation of alkylidenecycloalkanone followed by acidic
alumina-mediated regioselective ring expansion of the cyclopropyl
ketone. The scope of the reaction was investigated using alkylidenecycloalkanones
derived from tetralone, indanone, and benzosuberone to afford 2-aryl-3-bromofurans
fused to various benzocycloalkanes. Representative examples of stereoconvergent
dibromocyclopropanation and total aromatization of the furobenzocycloalkane
are also reported
Synthesis of Fused Bromofurans via Mg-Mediated Dibromocyclopropanation of Cycloalkanone-Derived Chalcones and Cloke–Wilson Rearrangement
A convenient two-step sequence for the conversion of
alkylidenecycloalkanones
to bromofurans is reported. The steps involve Mg-mediated diastereoselective
dibromocyclopropanation of alkylidenecycloalkanone followed by acidic
alumina-mediated regioselective ring expansion of the cyclopropyl
ketone. The scope of the reaction was investigated using alkylidenecycloalkanones
derived from tetralone, indanone, and benzosuberone to afford 2-aryl-3-bromofurans
fused to various benzocycloalkanes. Representative examples of stereoconvergent
dibromocyclopropanation and total aromatization of the furobenzocycloalkane
are also reported
One-Pot Regioselective Synthesis of <i>meta</i>-Terphenyls via [3 + 3] Annulation of Nitroallylic Acetates with Alkylidenemalononitriles
A highly
efficient one-pot method has been developed for the synthesis
of <i>meta</i>-terphenyls via a regioselective [3 + 3] annulation-elimination
sequence involving Morita–Baylis–Hillman (MBH) acetates
of nitroalkenes and alkylidenemalononitriles. The reaction takes place
in a regioselective manner under mild conditions (Et<sub>3</sub>N,
room temperature) to afford a wide variety of <i>meta</i>-terphenyls bearing aryl, heteroaryl and styrenyl groups. This novel
[3 + 3] annulation takes advantage of the 1,3-bielectrophilic character
of MBH acetates and 1,3-binucleophilic character of alkylidenemalononitriles
and proceeds in a cascade fashion comprising an S<sub>N</sub>2′
substitution, intramolecular 6-<i>endo-trig</i> Michael
addition and double elimination. Representative synthetic transformations
of the products, for instance, to <i>meta</i>-terphenyl
derived isoindolinones have also been demonstrated
Memory Effect and Crystallization of ( R ,S )-2-Chloromandelic Acid Glass
info:eu-repo/semantics/publishe