The addition of allyltrimethylsilane to tert-butanesulfinyl imines triggered by tetra-n-butylammonium fluoride (TBAF) in the presence of 4A molecular sieves has been studied, and homoallylsulfinamides were obtained ...The addition of allyltrimethylsilane to tert-butanesulfinyl imines triggered by tetra-n-butylammonium fluoride (TBAF) in the presence of 4A molecular sieves has been studied, and homoallylsulfinamides were obtained in good yields with moderate to high diastereoselectivities.展开更多
An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide(TBAH) is described. The method is very practical and the alkylation can occur at room temperature...An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide(TBAH) is described. The method is very practical and the alkylation can occur at room temperature and the yields of the N-alkyl pyrimidines and purines were found to be excellent.展开更多
A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using t...A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.展开更多
The mechanism of the adsorption-parallel catalytic wave of cinnamic acid (C6H5-CH = CH-COOH) in acetate buffer (pH = 4.0)-H2O2-tetra-n-butylammonium bromide (Bu4N · Br) solution was studied by the linear-sweep po...The mechanism of the adsorption-parallel catalytic wave of cinnamic acid (C6H5-CH = CH-COOH) in acetate buffer (pH = 4.0)-H2O2-tetra-n-butylammonium bromide (Bu4N · Br) solution was studied by the linear-sweep polarography, cyclic voltammetry and digital simulation approach. Experimental results indicate that the reduction mechanism of cinnamic acid isEC dim E’ process, in which the C = C double bond of cinnamic acid first undergoes 1e, 1H+ reduction to produce an intermediate free radical C6H5-CH-CH2-COOH(E), then the further reduction of the free radical in 1e, 1H+ addition (E’) occurs simultaneously with a dimerization reaction between two free radicals (Cdim). Bu4N· Br enhances the polarographic current of cinnamic acid and shifts the peak potential to positive direction. The enhancement action of Bu4N· Br is due to the adsorption of cinnamic acid induced by Bu4N+ species. In addition, H2O2 causes the parallel catalytic wave of cinnamic acid. The mechanism of the catalytic wave isEC’ process because H2O2 oxidizes the free radical of cinnamic acid to regenerate the original C =C bond(C’), preventing both the further reduction and the dimerization of the free radicals. The apparent rate constantk f of the oxidation reaction is 1.35×102 mol· L-1· s-1. A new class of catalytic waves for organic compounds, the adsorption-parallel catalytic waves upon the dual enhancement action of both the surfactant and oxidant, has been presented.展开更多
A practical procedure for palladium catalyzed Suzuki cross-coupling reaction of arylboronic acids with aryl hal-ides, including aryl chlorides in molten tetra-n-butylammonium bromide (TBAB) was developed. The reaction...A practical procedure for palladium catalyzed Suzuki cross-coupling reaction of arylboronic acids with aryl hal-ides, including aryl chlorides in molten tetra-n-butylammonium bromide (TBAB) was developed. The reaction exhibits high efficiency and functional group tolerance. The recovery of the catalyst and molten n-Bu4NBr was also investigated.展开更多
A mild and efficient n Bu4 NBr-mediated oxidative cycloaromatization to prepareβ-carbolines from readily available tryptophans and aldehydes is described.The reaction is practical and allows the synthesis ofβ-carbol...A mild and efficient n Bu4 NBr-mediated oxidative cycloaromatization to prepareβ-carbolines from readily available tryptophans and aldehydes is described.The reaction is practical and allows the synthesis ofβ-carbolines on gram-scale.Some of products crystallized from the reaction mixture and were easily removed by filtration,obviating the need for chromatographic separation.展开更多
文摘The addition of allyltrimethylsilane to tert-butanesulfinyl imines triggered by tetra-n-butylammonium fluoride (TBAF) in the presence of 4A molecular sieves has been studied, and homoallylsulfinamides were obtained in good yields with moderate to high diastereoselectivities.
基金Supported by the National Natural Science Foundation of China(No. 20172007) and the"985"Programs, Ministry of Educa-tion of China
文摘An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide(TBAH) is described. The method is very practical and the alkylation can occur at room temperature and the yields of the N-alkyl pyrimidines and purines were found to be excellent.
基金fnancial support from the Research Council of the University of Sistan and Baluchestan
文摘A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.
文摘The mechanism of the adsorption-parallel catalytic wave of cinnamic acid (C6H5-CH = CH-COOH) in acetate buffer (pH = 4.0)-H2O2-tetra-n-butylammonium bromide (Bu4N · Br) solution was studied by the linear-sweep polarography, cyclic voltammetry and digital simulation approach. Experimental results indicate that the reduction mechanism of cinnamic acid isEC dim E’ process, in which the C = C double bond of cinnamic acid first undergoes 1e, 1H+ reduction to produce an intermediate free radical C6H5-CH-CH2-COOH(E), then the further reduction of the free radical in 1e, 1H+ addition (E’) occurs simultaneously with a dimerization reaction between two free radicals (Cdim). Bu4N· Br enhances the polarographic current of cinnamic acid and shifts the peak potential to positive direction. The enhancement action of Bu4N· Br is due to the adsorption of cinnamic acid induced by Bu4N+ species. In addition, H2O2 causes the parallel catalytic wave of cinnamic acid. The mechanism of the catalytic wave isEC’ process because H2O2 oxidizes the free radical of cinnamic acid to regenerate the original C =C bond(C’), preventing both the further reduction and the dimerization of the free radicals. The apparent rate constantk f of the oxidation reaction is 1.35×102 mol· L-1· s-1. A new class of catalytic waves for organic compounds, the adsorption-parallel catalytic waves upon the dual enhancement action of both the surfactant and oxidant, has been presented.
文摘A practical procedure for palladium catalyzed Suzuki cross-coupling reaction of arylboronic acids with aryl hal-ides, including aryl chlorides in molten tetra-n-butylammonium bromide (TBAB) was developed. The reaction exhibits high efficiency and functional group tolerance. The recovery of the catalyst and molten n-Bu4NBr was also investigated.
基金National Natural Science Foundation of China (Nos. 21172120 and 21472093)Tianjin Municipal Science and Technology Commission (No. 14JCYBJC20600) for financial support
文摘A mild and efficient n Bu4 NBr-mediated oxidative cycloaromatization to prepareβ-carbolines from readily available tryptophans and aldehydes is described.The reaction is practical and allows the synthesis ofβ-carbolines on gram-scale.Some of products crystallized from the reaction mixture and were easily removed by filtration,obviating the need for chromatographic separation.