Reaction of Aromatic Aldehydes with Ammonium Acetate

By reaction of aromatic aldehydes with ammonium acetate a series of 1,2-diaryl-1,2-diaminoethanes and their derivatives was obtained. The mechanism of reaction was suggested and its principal stages were proved. Reactions with ammonium acetate of aromatic aldehydes containing ortho-substituents resulted in the corresponding 2,4,5-triaryl-4,5-dihydroimidazoles.     

芳亚甲基丙二腈、芳亚甲基氰乙酰胺的固相合成

芳醛和丙二腈、氰乙酰胺在NH4Ac催化下经固相反应高产率的得到芳亚甲基丙 二腈和芳亚甲基氰乙酰胺。     

芳香化合物在碘或碘化铵催化作用下的单溴代反应

研究了芳香化合物在碘或碘化铵催化作用下的单溴代选择性反应, 该反应是经过有机高价碘中间体进行的. 通过该反应, 富电子芳香化合物在碘或碘化铵催化作用下很容易与溴化钾、 间氯过氧苯甲酸、 对甲苯磺酸和少量苯的混合物发生反应, 常温下短时间内得到产率良好并具有区域选择性的单溴代芳香化合物. 考察了反应条件的影响, 提出了可能的反应机理, 为简单快速合成单溴代芳香化合物提供了新方法.     

微波辅助法合成Hantzsch酯

以芳香醛、乙酰丙酮及碳酸氢铵为原料,固载路易斯酸蒙脱土为催化剂,通过微波辅助法催化合成了5个Hantzsch酯类化合物,其结构经¹H NMR和IR确证。考察了催化剂、溶剂、温度、时间和氮源对产率的影响。结果表明：反应温度60 ℃,微波辐照时间10 min, n(芳香醛) :n(乙酰乙酸乙酯) :n(碳酸氢铵)=2.0:2.0:1.0,氯化镍固载蒙脱土为催化剂（10%）,产率高达97.8%。     

Ecofriendly and Efficient One-Pot Procedure for the Synthesis of Quinazoline Derivatives Catalyzed by an Acidic Ionic Liquid Under Aerobic Oxidation Conditions

A three-component condensation reaction between 2-aminobenzophenone derivatives, formaldehyde or aromatic aldehydes, and ammonium acetate efficiently provides substituted quinazolines in a one-pot reaction in the presence of Brönsted acidic ionic liquid, 1-methylimidazolium triflouroacetate ([Hmim]TFA), in conjunction with aerobic oxidation. The ionic liquid was separated from the reaction mixture by simple extraction and was recycled three times without considerable loss in activity.     

Silica‐bonded S‐sulfonic Acid as a Recyclable Catalyst for Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones

2,3‐Dihydroquinazolin‐4(1H)‐one derivatives were synthesized via a one‐pot, three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica‐bonded S‐sulfonic acid in ethanol at 80°C. The reaction work‐up is simple and the catalyst is easily separated from the products by filtration. The heterogeneous catalyst was recycled for ten runs upon the condensation reaction of isatoic anhydride and 4‐chlorobenzaldehyde with ammonium acetate without losing its catalytic activity.     

Silica-bonded N-propylsulfamic acid as a recyclable catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones

2,3-Dihydroquinazolin-4(1H)-one derivatives are synthesized via a one-pot,three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica-bonded N-propylsulfamic acid(SBNPSA) in refluxing ethanol.     

Microwave‐Assisted,One‐Pot Multicomponent Synthesis of Some New Cyanopyridines

An efficient and facile synthesis of cyanopyridines via a one‐pot four‐component reaction of aromatic aldehydes, acetophenones, malononitrile, or 2‐aminoprop‐1‐ene‐1,1,3‐tricarbonitrile in presence of sodium alkoxide or ammonium acetate under both microwave and thermal reaction conditions was introduced.     

Kröhnke reaction in aqueous media: one-pot clean synthesis of 4′-aryl-2,2′:6′,2″-terpyridines

A clean aqueous Kröhnke reaction process has been accomplished via a one-pot procedure of 2-acetylpyridine with aromatic aldehyde and ammonium acetate under microwave irradiation or conventional heating conditions. This method is convenient, economic and environmental friendly.     

Palladium(0) nanoparticles: an efficient catalyst for the one-pot synthesis of polyhydroquinolines

A mild, concise, and efficient protocol for the synthesis of polyhydroquinoline via four component reaction of aromatic aldehydes, dimedone, ethyl acetoacetate or ethyl cyanoacetate, and ammonium acetate using Pd-nanoparticles is described. The same phenomenon was observed in the case of arylmethylene bis(3-hydroxy-2-cyclohexene-1-ones), ethyl acetoacetate, ammonium acetate, and Pd-nanoparticles in one-pot. The present method also allows us to synthesize highly functionalized title compounds from simple and readily available inputs.     

Cerium (IV) ammonium nitrate-mediated reactions: Simple route to benzimidazole derivatives

The reaction of o-phenylenediamine with aromatic aldehydes in MeOH at room temperature catalyzed by cerium (IV) ammonium nitrate (CAN) afforded either 2-aryl-1-arylmethyl-1H-benz-imidazoles and/or 2-aryl-substituted benzimidazoles.     

微波辐射一步合成对-芳基多氢喹啉衍生物

芳醛、5,5-甲基-1,3-环已二酮与乙酰乙酸乙酯或丙二酸亚异丙酯在醋酸铵存在下,用微波辐射一步合成了4-芳基-2,7,7-三甲-3-乙氧羰基-5-氧代-1,4,5,6,7,8-六氢喹啉和4-芳基-7,7-二甲基2,5-二氧代-1,2,3,4,5,6,7,8-八氢喹啉,反应在2～8min内完成,产率优良。     

Asymmetric Michael reaction promoted by new chiral phase-transfer catalysts

A catalytic asymmetric Michael reaction promoted by new chiral quaternary ammonium salts is described. The products are obtained with moderate ee (up to 75% ee), and the enantioselectivity is strongly dependent on both the substituents on the aromatic rings and the ammonium moiety in the catalysts.     

芳基咪唑并[4,5-f][1,10]菲咯啉的无溶剂绿色合成研究

以菲咯啉二酮、苯甲醛及其衍生物和醋酸铵为原料,采用无溶剂绿色研磨工艺,合成了芳基咪唑并菲咯啉化合物.通过对不同反应条件的筛选,得到一条高效、简便、绿色的合成芳基咪唑并菲咯啉化合物路线,不同的芳醛与菲咯啉二酮都可以较高的收率得到相应的芳基咪唑并[4,5-f][1,10]菲咯啉.     

Synthesis of Morita-Baylis-Hillman-type adducts by unprecedented reaction of 1-phenyl-2-(trimethylsilyl)acetylene with aromatic aldehydes catalyzed by quaternary ammonium fluorides derived from cinchonine

The quaternary ammonium fluoride derived from cinchonine efficiently catalyzed the reaction of 1-phenyl-2-(trimethylsilyl)acetylene with aromatic aldehydes to give the β-branched Morita-Baylis-Hillman-type adducts.     

Nano‐TiO2 as an Efficient Catalyst for Tandem Knoevenagel–Michael‐Cyclocondensation Reaction of Dimedone with Aromatic Aldehydes and Ammonium Acetate or Aromatic Amines under Solvent‐free Conditions

TiO₂ nanoparticles in anatase and rutile forms was characterized and studied by several techniques including X‐ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and successfully applied as an efficient and heterogeneous catalyst in the synthesis of 1,8‐dioxo‐decahydroacridines via the one‐pot multi‐component condensation reaction of dimedone with aromatic aldehydes and ammonium acetate or aromatic amines under mild and solvent‐free conditions.     

Lewis base catalyzed Mannich-type reactions between trimethylsilyl enol ethers and aldimines

Lewis base catalyzed Mannich-type reaction between trimethylsilyl enol ethers and N-tosylaldimines is described. Nitrogen anions generated from amides or imides such as lithium benzamide or potassium phthalimide are found to be effective Lewis base catalysts in DMF at room temperature to afford the corresponding beta-amino carbonyl compounds in good to high yields; the oxygen anion generated from carboxylic acids such as lithium acetate was also found to be effective in dry DMF. The above-mentioned lithium acetate-catalyzed Mannich-type reaction between aldimines and various trimethylsilyl (TMS) enol ethers such as silyl ketene acetal proceeded smoothly even in water-containing DMF. Then, Lewis base catalyzed three-component Mannich-type reactions of TMS enol ether, tosylamide, and aromatic aldehyde having electron-withdrawing group such as p-nitrobenzaldehyde were investigated. The reaction proceeded smoothly to afford the corresponding beta-amino ester in good yield. Further, ammonium carboxylates such as tetrabutyl ammonium acetate or tetrabutyl ammonium benzoate were found to be more effective Lewis base catalysts in the above-mentioned Mannich-type reaction. The synthesis proceeded in various solvents at lower temperatures. The reaction between aldimines and TMS enol ethers generated from thioester and various ketones such as propiophenone or cyclohexanone also proceeded smoothly to afford the corresponding beta-amino carbonyl compounds in high yields with good to high anti-selectivities.     

5-芳亚苄基巴比妥酸的固态合成

固相合成;5-芳亚苄基巴比妥酸的固态合成     

One-pot Synthesis of 1,8-Dioxo-decahydroacridine Derivatives in Aqueous Media

A new and efficient method for the synthesis of 1,8‐dioxo‐9‐aryl‐decahydroacridine derivatives was developed via a one‐pot three component reaction of dimedone, aromatic aldehydes and ammonium acetate in the presence of ammonium chloride, or Zn(OAc)₂·2H₂O or L‐proline separately in water in the short period of time and high yields.     

A facile four-component tandem protocol for the synthesis of novel 2,6-diaryl-2,3-dihydro-1H-pyridin-4-ones

A one-pot, four-component reaction of 1-(phenylsulfinyl)- or 1-(4-chlorophenylsulfinyl)propan-2-one, aromatic aldehydes and ammonium acetate in a 1:2:1 molar ratio affords a series of new 2,6-diaryl-2,3-dihydro-1H-pyridin-4-ones. This reaction proceeds presumably via a double Mannich reaction-elimination tandem sequence.