Solvent‐free synthesis of propargylamines catalyzed by an efficient recyclable ZnO‐supported CuO/Al2O3 nanocatalyst

An efficient nanocatalyst of ZnO‐supported CuO/Al₂O₃ (CuO/ZnO/Al₂O₃ nanocatalyst) was prepared by the co‐precipitation method and characterized by scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray powder diffraction and Brunauer–Emmett–Teller surface area analysis. CuO/ZnO/Al₂O₃ nanocatalyst proved to be a very efficient catalyst on the synthesis of propargylamines under solvent‐free conditions in high yields. Moreover, the catalyst can be recyclable without reducing catalytic activity up to five times.     

Synthesis of imidazo[1,2-a]pyridine-6-carbohydrazides and 1H-pyrido[1,2-a]pyrimidine-7-carbohydrazides

The one-pot, multicomponent synthesis of imidazopyridine and pyridopyrimidine fused heterocyclic systems from readily available diamines, l,l-bis(methylthio)-2-nitroethene, cyanoacetohydrazide and aromatic aldehydes in good to high yields is described. This protocol has the advantages of simple work-up, mild reaction conditions, absence of catalyst and provides an entry point to fused heterocyclic structures.     

偕二酸酯的无溶剂合成

以醛和酸酐为原料,溴化锌为催化剂,无溶剂条件下高产率地合成了偕二酸酯(其中醛与苯甲酸酐的反应是首次报道)。部分产物的结构经NMR,IR和MS表征。     

高烯丙基醇和高炔丙基醇的无溶剂合成

在活化锌粉的促进下,通过羰基化合物的烯丙基化和炔丙基化反应,实现了高烯丙基醇和高炔丙基醇的快速无溶剂合成,收率72％～88％。产物的结构经1^H NMR,MS和元素分析确证。     

Asymmetric organocatalytic oxy-Michael addition of alcohols to α,β-unsaturated aldehydes

A 1,4-addition of alcohols to α,β-unsaturated aldehydes was found to be efficiently promoted by biphenyldiamine-based catalyst 3 without formation of the acetals. An asymmetric variant of this reaction has also been performed by designing a novel axially chiral organocatalyst (R)-10c.     

不需加催化剂在纯水相介质中进行芳香醛与5,5-二甲基-1,3-环己二酮的缩合反应

在纯水相中,不另加任何催化剂可以十分方便、有效地通过芳香醛与5,5-二甲基-1,3-环己二酮间的缩合反应合成氧杂葸二酮类衍生物.该反应只需在热水中搅拌下即可有效进行.而且这种方法具有明显的环境友好、高产率和操作过程简便的优点.     

微波辐射下合成5-芳亚甲基-2,3-二芳基-4-噻唑啉酮类化合物

在水介质中,以四丁基溴化铵(TBAB)作催化剂,微波辐射下使芳醛与4-噻唑啉酮反应合成一系列5-芳亚甲基-2,3-二芳基-4-噻唑啉酮类化合物.该反应具有反应时间短、产率高、环境友好、后处理简便等优点.所有化合物均经IR,MS,1H NMR和元素分析确定.同时用X射线衍射法测定了化合物4a的晶体结构.     

硅胶硫酸:一种在温和及无溶剂条件下一锅法合成1,4-二氢吡啶的高效多相催化剂(英文)

A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields,and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.     

New three-component condensation reaction: synthesis of 1-[(alkylthio)(phenyl)methyl]-naphthalene-2-ol catalyzed by bromodimethylsulfonium bromide (BDMS)

Bromodimethylsulfonium bromide acts as an efficient catalyst for one pot three component condensation reactions of aldehydes, 2-naphthol, and thiols in acetonitrile at room temperature. Various aliphatic and aromatic thiols undergo conjugate addition with in situ generated enone in acetonitrile and provide good yields. The main features of this procedure are mild reaction conditions, good yields, and operational simplicity.