超声辐射下NH4OAc高效催化合成2-取代苯并咪唑类衍生物（英文）

超声辐射下,以NH4OAc为催化剂,利用芳香醛和邻苯二胺一锅法合成了一系列2-取代苯并咪唑类衍生物,该方法具有反应条件温和、收率高的特点。     

Lithium bromide catalyzed solvent free method for synthesis of 2-substituted benzimidazoles and imidazopyridines

<正>The first successful lithium bromide mediated solvent free condensation of arylenediamine and esters to obtain 2-substituted benzimidazole and imidazopyridine in good to excellent yields is described.     

One-pot synthesis of 2-amino-4H-chromenes catalyzed by Fe(ClO4)3/SiO2

Russian Journal of General Chemistry - A highly efficient one-pot three-component synthesis of 2-amino-3-cyano-4H-chromenes has been developed by annulation of aldehydes, malononitrile and dimedone...     

One-pot three-component coupling reaction: solvent-free synthesis of novel 3-substituted indoles catalyzed by PMA-SiO2

Solvent-free PMA-SiO₂-catalyzed synthesis of 3-substituted indole derivatives by a one-pot three-component coupling reaction between aldehyde, N-methyl aniline and indole is described.     

One-pot asymmetric synthesis of 2-aryl-2,3-dihydro-4-quinolones catalyzed by amino acid-derived sulfonamides

An organocatalyzed approach to the asymmetric synthesis of 2-aryl-2,3-dihydro-4-quinolones using amino-acid derived sulfonamides as organocatalysts, which can be easily prepared starting from l-proline, l-alanine, and l-phenylalanine, has been developed in high yields (up to 92%) and with moderate to good enantioselectivities (up to 74% ee). Additionally, opposite enantioselectivities for primary and secondary amino acid sulfonamides have also been observed.     

Liquid-phase synthesis of 2-substituted benzimidazoles, benzoxazoles and benzothiazoles

A novel acid fluoride for use in the liquid-phase synthesis of substituted benzimidazoles, benzoxazoles and benzothiazoles was developed. Its synthetic utility is exemplified by a structurally diverse set of aromatic heterocycles. Final cleavage is achieved by treatment with sodium methoxide in methanol for 12 h. The corresponding benzimidazoles, benzoxazoles and benzothiazoles were obtained in good isolated yields (22-62%, four steps).     

硫酸氢钾催化一锅法合成1-乙酰胺烷基-2-萘酚

以硫酸氢钾为催化剂,在无溶剂条件下催化2-萘酚和乙酰胺分别与苯甲醛、对硝基苯甲醛、水杨醛、茴香醛、香兰素等五种芳香醛的三组分反应,利用一锅法合成了系列1-乙酰胺烷基-2-萘酚.以1-乙酰胺基苯甲基-2-萘酚(AAN)的合成为模板反应考察了催化剂用量、反应温度、原料配比及反应时间等因素对产物收率的影响.结果表明,硫酸氢钾催化合成AAN反应的适宜条件为:n(2-萘酚)∶n(苯甲醛)∶n(乙酰胺)∶n(硫酸氢钾)=1∶1.2∶1.2∶0.05,90℃下反应40min,AAN的收率达92.1%.硫酸氢钾对其他四种反应也有较理想的催化作用,目标产物收率为69.1%～94.0%.     

One-pot synthesis of 4-substituted isoquinolinium zwitterionic salts by metal-free C-H bond activation

The unprecedented isoquinolinium zwitterionic salts with an unusual C-4 substitution pattern were efficiently prepared via the multicomponent reaction of in situ formed N-benzylisoquinolinium bromide with aromatic aldehydes and cyclic 1,3-dicarbonyl compounds.     

One-pot synthesis of tetrahydrochromene derivatives catalyzed by lipase

An efficient and green one-pot synthesis route for tetrahydrochromene derivatives was developed. Lipase from Porcine pancreas (PPL) shows excellent catalytic activity and exerts good adaptability to different substrates in the reaction. All the reactions go smoothly and provide tetrahydrochromene derivatives with isolate yield up to 97% under room temperature. This lipase-catalyzed multistep conversion method has provided a new strategy to synthesize chromene derivatives and expanded the application of enzyme in organic synthesis.     

One-pot synthesis of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones by the reaction of 2-isothiocyanatobenzoates with organolithiums

An efficient one-pot procedure for the preparation of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones from 2-isothiocyanatobenzoates has been developed. Thus, 2-isothiocyanatobenzoates were reacted with organolithiums including lithium enolates of acetates and tertiary acetamides in THF at −78 °C to give the desired products in generally good yields.     

DBSA mediated chemoselective synthesis of 2-substituted benzimidazoles in aqueous media

An efficient synthetic method has been developed for the facile synthesis of 2-substituted benzimidazoles in organized aqueous media in the presence of a surfactant (viz. DBSA) as catalyst and I₂ as co-catalyst. The method described has the advantages of operational simplicity, excellent yields, high chemoselectivity, and clean and green reaction profile.     

Eco-friendly synthesis of 2-substituted benzothiazoles catalyzed by silica sulfuric acid

2-Substituted benzothiazoles have been synthesized via one-pot reaction from aromatic aldehydes and o-aminothiophenol catalyzed by silica sulfuric acid in absolute methanol at room temperature. The remarkable advantages offered by this method are an environmentally friendly and reusable catalyst, a simple procedure, mild conditions, short reaction times, and good to excellent yields of products.     

Imidazolium chloride-catalyzed synthesis of benzimidazoles and 2-substituted benzimidazoles from o-phenylenediamines and DMF derivatives

A facile, general, and economical synthesis of diversely functionalized benzimidazoles and 2-substituted benzimidazoles has been realized via the imidazolium chloride-catalyzed cyclization of o-phenylenediamines with DMF derivatives. This protocol shows a broad substrate scope for aliphatic, aromatic, and heteroaromatic amides. A series of benzimidazoles and 2-substituted benzimidazoles have been obtained in moderate to excellent yields.     

One-pot synthesis of 1,5-diketones catalyzed by barium isopropoxide

A tandem cross-coupling reaction of aryl methyl ketones with aromatic aldehydes has been accomplished employing barium isopropoxide as a catalyst, in which barium enolates are generated and then three consecutive reactions (aldol reaction/β-elimination/conjugate addition) occur; this one-pot procedure is a convenient method to obtain symmetrical 1,5-diketones in good yields. In some cases, addition of iso-propanol is effective in improving the chemical yield.     

One-pot sequential synthesis of 1,2-disubstituted benzimidazoles under metal-free conditions

An easy and inexpensive method has been developed to access 1,2-disubstituted benzimidazoles following a one-pot sequential coupling/reduction/cyclization process under metal-free neutral conditions.     

无溶剂微波照射下2－取代苯并咪唑的合成

用PPA作催化剂，在无溶剂微波照射下合成了10种2－取代苯并咪唑，为该类化 合物的合成提供了一种新方法。与常规方法相比，反应时间大大缩短，产率与传统 合成方法相当。