نتایج جستجو برای: aromatic aldehydes
تعداد نتایج: 48669 فیلتر نتایج به سال:
Thirty-seven commercial aldehydes containing aliphatic chains and aromatic rings as well as heteroaromatic rings were evaluated for their inhibitory activities against Chinese amaranth (Amaranthus tricolor L.) and barnyardgrass (Echinochloa crus-galli (L.) Beauv). Polysorbate 80 (Tween® 80) was used as a surfactant and the research was preliminarily conducted at 400 μM of all aldehydes. Among t...
a simple and efficient one-pot, three-component strecker reaction of protected amino acids, aromatic aldehydes, and trimethylsilyl cyanide has been developed for the synthesis of chiral α-amino nitriles. the reaction was carried out in the presence of catalytic amount of phosphotungstic acid (h3[p(w3o10)4]) as an environmentally friendly catalyst.
silica-bonded n-propyltriethylene-tetramine (sbnptt) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4h-chromenes. chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oc under solvent-free conditions. the heterogeneous solid base showed much the same efficiency when u...
efficient and one-pot synthesis of 1,8-dioxo-octahydroxanthenes was described by knoevenagel condensation, michael addition and cyclodehydration of dimedone. this reaction was carried out through condensation of dimedone and various aromatic aldehydes in the presence of task-specific brønsted acidic ionic liquid under solvent free conditions. the catalyst could be recycled five times without si...
BACKGROUND Although the nucleophilic difluoromethylation of aldehydes, ketones, and imines has been realized with PhSO(2)CF(2)H and related reagents, there are still no reports on the enantioselective nucleophilic reactions. RESULTS With a chiral quaternary ammonium salt as the catalyst and KOH as the base, we describe the first enantioselective difluoromethylation of aromatic aldehydes with ...
New 1-[1-(1H-indol-3-yl) alkyl]-1H-indoles, surprisingly, have been obtained from the addition of indole to a variety of aldehydes under neat conditions. CaO, present in excess, was fundamental for carrying out the reaction with paraformaldehyde. Under the same reaction conditions, aromatic and heteroaromatic aldehydes afforded only classical bis (indolyl) aryl indoles. In this paper, the role ...
The first example of a homogeneous silver(I)-catalyzed aerobic oxidation of aldehydes in water is reported. More than 50 examples of different aliphatic and aromatic aldehydes, including natural products, were tested, and all of them successfully underwent aerobic oxidation to give the corresponding carboxylic acids in extremely high yields. The reaction conditions are very mild and greener, re...
A water soluble, Bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. Cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally fri...
Friedel–Crafts synthesis of triarylmethanes over 3-methyl-1-sulfonic acid imidazolium tetrachloroaluminate under green conditions:In this work, Friedel–Crafts (FC) alkylation of various arenes with aromatic aldehydes catalyzed by 3-methyl-1-sulfonic acid imidazoliumtetrachloroaluminate {[Msim]AlCl4}, as a green catalyst, to prepare triarylmethanes (TAMs) has been carried out. Some aromatic alde...
Silyl ketene imines derived from a variety of alpha-branched nitriles have been developed as highly useful reagents for the construction of quaternary stereogenic centers via the aldol addition reaction. In the presence of SiCl4 and the catalytic action of chiral phosphoramide (R,R)-5, silyl ketene imines undergo extremely rapid and high yielding addition to a wide variety of aromatic aldehydes...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید