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91.
A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V(HSO4)3 in solution and under solvent free conditions.Mild reaction conditions,high yields of the products,easy procedure and selective acetylation of alcohols and phenols in the presence of amines and thiols are the main advantages of this procedure. 相似文献
92.
Qing Han Li 《中国化学快报》2009,20(7):793-796
Six new asymmetric thiocarbonohydrazones 3a-3f were synthesized from following steps:firstly hydrazine hydrate reacted with carbon disulfide to form thiocarbonohydrazide(1) under microwave irradiation.Then compound(1) reacted with ketone and different aldehydes step by step to give 3a-3f with excellent yields under solvent-free conditions using microwave irradiation.Their structures have been determined by elemental analysis,IR,MS and ~1H NMR data. 相似文献
93.
Barahman Movassagh Mohammad Soleiman-Beigi 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):409-411
Abstract A simple, highly efficient, and green protocol has been developed for preparation of sulfides from alkyl or aryl thiols and
benzyl-, allyl-, t-butyl, and adamantyl halides under solvent- and catalyst-free conditions.
Graphical abstract
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94.
A novel efficient procedure has been developed for the conjugate addition of amines to electron deficient alkenes. A series of metal oxides was synthesized for catalyzing the conjugate addition of amines and alkenes. After optimizing the reaction conditions, SrO was chosen as the most efficient catalyst for the reactions. The results show that the catalyst is very efficient for the conjugate addition of amines to electron deficient alkenes with the excellent yields in several minutes. Operational simplicity... 相似文献
95.
In this report, we described the synthesis and characterization of a variety of diaminotriarylmethane derivatives with dimethylamino
functional groups. These compounds were synthesized by the tandem regio-selective electrophilic aromatic substitution reaction
of N,N-dimethylaniline with aryl aldehydes to form the corresponding diaminotriarylmethane compounds. In our strategy, Bi(NO3)3 was used as a catalyst under solvent free conditions to afford the desired products in good to excellent yields.
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96.
CAO Jun-gang CAO Hui-min LIN Ying-jie LIANG Da-peng DUAN Hai-feng HAN Song-yang ZHAO Xue-zhong 《高等学校化学研究》2011,27(5):780-783
Lewis acidic guanidinium ionic liquid(LAGIL) 2c was used as a novel, efficient and recyclable catalyst for aminolysis of epoxides under solvent-free and room temperature conditions, giving the corresponding β-amino alcohols with moderate to excellent regioselectivity(up to 91:9) in high yields(up to 97%). In addition, LAGIL 2c was recycled three times without any loss of catalytic activity and selectivity to the product. 相似文献
97.
ZONG Chenglong ZENG Runsheng ZOU Jianping 《高等学校化学研究》2014,30(4):632-638
A direct and efficient approach to synthesize imidazo[1,2-α]pyridines through three-component one-pot reaction of 2-aminopyridine,aldehyde and terminal alkyne catalyzed by Cu-nanoparticles under solvent-free conditions has been developed.This method provides a rapid access to substituted imidazo[1,2-α]pyridines with good yields(up to 85%). 相似文献
98.
在Yb(NO3)3催化下, 芳香醛、 5,5-二甲基-1,3-环己二酮、 乙酰乙酸乙酯和醋酸铵在室温无溶剂条件下经超声辐射一锅法合成了一系列1,4-二氢吡啶衍生物, 反应时间为15~35 min, 产率为86%~97%. 该方法具有条件温和、 反应时间短且产率高的优点. 催化剂Yb(NO3)3对环境友好且可循环使用, 为此类化合物的合成提供了一种有效的新方法. 相似文献
99.
Monoglyceryl phenolic acids (MPAs) were known as the natural hydrophilic antioxidants which could be used in different fields such as food, pharmaceutical, cosmetic etc. A novel enzymatic route of MPAs synthesis by the alcoholysis of phenolic acid ethyl esters with glycerol under ultrasound irradiation in solvent free system was developed. Optimization of reaction parameters shows that a high conversion of above 97.4% can be obtained under the following conditions: phenolic acid ethyl esters to glycerol molar ratio of 1:10, with 6% catalyst (Novozym 435), at 60 °C and 200 rpm, with ultrasound input of 250 W, at 20 kHz frequency. Compared to the conventional stirring method, the activation energy for phenolic acid ethyl esters conversion was decreased from 65.0 kJ/mol to 32.1 kJ/mol under ultrasound promotion; the apparent kinetic constant (Vm/Km) increased above 1.2-folds; the lipase amount decreased to 50%; the time required for the maximum conversion reduced up to 3-folds without damaging the lipase activity, which is the fastest report for enzymatic synthesis of MPAs. 相似文献
100.
A novel and efficient route for the synthesis of 1,8-dioxooctahydroxanthenes and 14-aryl-14H-dibenzo[a,j]xanthenes is described through one-pot multi-component reaction of dimedone and 2-naphthol with various aryl aldehydes using ZnO nanoparticles under solvent-free conditions.This method provides a novel and improved pathway for the synthesis of xanthenes in the terms of excellent yields,short reaction times,reusability and low catalyst loading. 相似文献