Tonalid,an important fragrance ingredient with widespread applicatio n,was synthesized via two FriedelCrafts reactions,which were catalyzed by AlCl_(3).The traditional tonalid production was conducted in batch stirrin...Tonalid,an important fragrance ingredient with widespread applicatio n,was synthesized via two FriedelCrafts reactions,which were catalyzed by AlCl_(3).The traditional tonalid production was conducted in batch stirring tank reactors,suffering from low production capacity and the safety hazard of temperature runaway.To solve these problems,the continuous-flow technologies were developed for the highefficiency and intrinsically safe synthesis of tonalid in microreactors.Catalyst AlCl_(3)was neatly homogenized in proper solvents by forming complex with reactant,which was a necessary step for the continuous synthesis in microreactors.Several reaction conditions,including reactant molar ratio,catalyst concentration,temperature,and microchannel hydrodynamic diameter,were investigated for the two Friedel-Crafts reactions in micro reactors.At optimized conditions,the yields of the two Friedel-Crafts reactions were 44.15%and 97.55%,respectively.In comparison with the batch reactors,the reaction times of these two reactions could both be reduced by nearly two thirds in microreactors at the similar yield.展开更多
For efficient removal of thiophenic sulfur （S-） compounds from oils, a novel method is proposed here, i.e. one-pot alkylation desulfurization （OADS）, in which oil insoluble chlorinated polymer such as polyvinyl ch...For efficient removal of thiophenic sulfur （S-） compounds from oils, a novel method is proposed here, i.e. one-pot alkylation desulfurization （OADS）, in which oil insoluble chlorinated polymer such as polyvinyl chlo- ride （PVC） is used as the alkylating regent with Lewis acid as catalyst. The aromatic S-compounds are grafted to the polymer through Friedel-Crafts reaction and removed facilely along with the polymer. The OADS mechanism is identified by scanning electron microscope and analyzer with surface area and pore size of the polymer. The influ- ence of some factors on the OADS is studied, e.g. the type and amount of chlorinated polymers and Lewis acids. It is nroved that thionhene and benzothioDhene can be removed efficiently from oil by PVC＋AlCl3 mixture even in the presence of 25% （by mass） of benzene due to the synergetic effects of the adsorptive desulfurization of AlCl3 and the alkylation desulfurization of PVC.展开更多
The effect of microwave irradiation on the intermolecular and intramolecular Friedel-Crafts acylation of aromatic compounds was investigated. Microwave irradiation had no effect on the intermolecular reaction but had ...The effect of microwave irradiation on the intermolecular and intramolecular Friedel-Crafts acylation of aromatic compounds was investigated. Microwave irradiation had no effect on the intermolecular reaction but had an accelerating effect on the intramolecular reaction. This enhanced intramolecular reactivity that was attributed to the high probability of close proximity between the reaction sites.展开更多
The effects to elicit resistance reaction on oilseed rape (Brassica napus L. cv Xinongchangjiao ) by four partially N-acetylated chitosan 7B, 8B, 9B and 10B (Degree of acetylation (D. A.) is 30% , 20% , 10%, 0%, respe...The effects to elicit resistance reaction on oilseed rape (Brassica napus L. cv Xinongchangjiao ) by four partially N-acetylated chitosan 7B, 8B, 9B and 10B (Degree of acetylation (D. A.) is 30% , 20% , 10%, 0%, respectively) and Glycol chitosan (GC, D.A. is 0%) were investigated and compared. Results showed that chitosan were similar to salicylic acid (SA), and could induce resistance reaction, but the reaction was influenced by the degree of acetylation of chitosan. Fully deacetylated chitosans, 10B and GC, elicited chitinase activity, but partially acetylated chitosan, 7B, 8B and 9B, inhibited chitinase activity. Phenyalanine ammonia-lyase (PAL) was also elicited. Elicitor activity increased with on increasing degree of acetylation, 7B induced highest PAL activity among all chitosans. All chitosans induced peroxidase (POD) in a similar level. After elicited by glycol chitosan, like SA treatment, the seedlings increased disease resistance to Sclerotinia sclerotiorum significantly.展开更多
A mild and efficient method for the conversion of alcohols to their corresponding methoxymethyl ethers and acetates using benzyltriphenylphosphonium tribromide （BTPTB） as catalyst is described. All reactions were pe...A mild and efficient method for the conversion of alcohols to their corresponding methoxymethyl ethers and acetates using benzyltriphenylphosphonium tribromide （BTPTB） as catalyst is described. All reactions were performed under completely heterogeneous reaction conditions in good to high yields.展开更多
Substituted phenoxy acetyl chloride reacted with trimethyl phosphite to form an unexpected substituted phenoxy acetic acid ester, confirmed by ~1HNMR, IR and MS. The mechanism suggested is different from that of Arbuz...Substituted phenoxy acetyl chloride reacted with trimethyl phosphite to form an unexpected substituted phenoxy acetic acid ester, confirmed by ~1HNMR, IR and MS. The mechanism suggested is different from that of Arbuzov reaction.展开更多
The reaction between diphenylmethanols and substituted benzenes is useful to yield triarylmethane derivatives which are important skeletons in various functional materials and biologically relevant substances. The Rea...The reaction between diphenylmethanols and substituted benzenes is useful to yield triarylmethane derivatives which are important skeletons in various functional materials and biologically relevant substances. The Reactions were carried out under microwave irradiation as environmentally-friendly method. In cyclohexane, the reaction was accelerated under microwave irradiation as compared to under conventional heating. Also, when more than 0.8 equivalents of iron(III) chloride were used, the acceleration was observed. Notably, when iron(III) chloride and arenes were combined, the temperature of the reaction solution rose to 40°C. It is considered that a chemical species was formed upon coordination of iron(III) chloride to the diphenylmethanols or arenes.展开更多
Several aromatic ring-substituted N-acetyl-phenylalanine methyl esters were treated with POCl3 in refluxing benzene, which is the typical condition of B-N reaction. It was found that the normal B-N product 3, 4-dihydr...Several aromatic ring-substituted N-acetyl-phenylalanine methyl esters were treated with POCl3 in refluxing benzene, which is the typical condition of B-N reaction. It was found that the normal B-N product 3, 4-dihydroisoquinoline-3-carboxylic acid methyl ester and/or 5-benzyl-2-methyl-4-methoxy oxazole could be obtained. The result depended mainly upon the electron-donating property of the substitutes on the benzene ring. Strong electron-donating groups located at para- or ortho- to the cyclization site will facilitate the formation of the normal B-N product 2. On the other hand, the absence or weak electron-donating groups tended to yield the oxazole product 3. It was established that the formation of benzyl oxazole is the competitive path with the B-N reaction. In this article, an explanation was given based on the mechanism of Bishler-Napieralski reaction.展开更多
A benzyl oxazole compound 3 was obtained with an excellent yield of 90% when N-acetyl-(2'-methoxy-4',5'-methylenedioxy)-phenylalanine methyl ester 1 was refluxed in POCl1/benzene. However, the anticipated ...A benzyl oxazole compound 3 was obtained with an excellent yield of 90% when N-acetyl-(2'-methoxy-4',5'-methylenedioxy)-phenylalanine methyl ester 1 was refluxed in POCl1/benzene. However, the anticipated product 3,4-dihydrosioquinoline-3-carboxylic acid methyl ester 2 could not be found. The mechanism was discussed in this article.展开更多
A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared.The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Craft...A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared.The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields(up to 99%) and good to excellent enantioselectivies(up to> 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF_(3)-β-disubstituted nitroalkene was favorable.展开更多
The present study deals with the study of some Friedel-Crafts alkylating system and the accurate measurement of hyperfine coupling constants by ESR and ENDOR techniques. The results indicate that the observed ESR spec...The present study deals with the study of some Friedel-Crafts alkylating system and the accurate measurement of hyperfine coupling constants by ESR and ENDOR techniques. The results indicate that the observed ESR spectra are due to polycyclic aromatic radical cations formed from their parent hydrocarbons.It is suggested that benzyl halides produced in the Friedel-Crafts alkylating reaction undergo Scholl condensation reaction to give polycyclic aromatic hydrocarbons, which were converted into the corresponding polycyclic aromatic radical cations in the presence of aluminum chloride.展开更多
A series of pyrazolone derivatives bearing a tetrasubstituted chiral center were prepared by virtue of a Lewis acid-catalyzed Friedel-Crafts reaction,in which a chiral copper complex was employed as the catalyst.This ...A series of pyrazolone derivatives bearing a tetrasubstituted chiral center were prepared by virtue of a Lewis acid-catalyzed Friedel-Crafts reaction,in which a chiral copper complex was employed as the catalyst.This reaction can be carried out smoothly under mild condition to afford the pyrazolone derivatives with high yields(up to 85%)and excellent enantioselectivities(up to 99%).In addition,the gram scale synthesis proved the practicality of this reaction.展开更多
A novel pyrrolo-benzoxaborole,6-（pyrrol-1-yl）-1,3-dihydro-1-hydroxy-2,1-benzoxaborole,was synthesized with 27%overall yield over six steps from 2-bromo-1-methyl-4-nitrobenzene as starting material.Its derivatization...A novel pyrrolo-benzoxaborole,6-（pyrrol-1-yl）-1,3-dihydro-1-hydroxy-2,1-benzoxaborole,was synthesized with 27%overall yield over six steps from 2-bromo-1-methyl-4-nitrobenzene as starting material.Its derivatization was achieved via Friedel-Crafts reaction catalyzed by anhydrous stannic chloride with various acyl chlorides giving 3-acyl-1-phenylpyrroles as the main products.展开更多
基金financial support for this work from the National Natural Science Foundation of China(No.21706034)the Natural Science Foundation of Fujian Province(No.2021J01645)the Key Program of Qingyuan Innovation Laboratory(No.00221004)。
文摘Tonalid,an important fragrance ingredient with widespread applicatio n,was synthesized via two FriedelCrafts reactions,which were catalyzed by AlCl_(3).The traditional tonalid production was conducted in batch stirring tank reactors,suffering from low production capacity and the safety hazard of temperature runaway.To solve these problems,the continuous-flow technologies were developed for the highefficiency and intrinsically safe synthesis of tonalid in microreactors.Catalyst AlCl_(3)was neatly homogenized in proper solvents by forming complex with reactant,which was a necessary step for the continuous synthesis in microreactors.Several reaction conditions,including reactant molar ratio,catalyst concentration,temperature,and microchannel hydrodynamic diameter,were investigated for the two Friedel-Crafts reactions in micro reactors.At optimized conditions,the yields of the two Friedel-Crafts reactions were 44.15%and 97.55%,respectively.In comparison with the batch reactors,the reaction times of these two reactions could both be reduced by nearly two thirds in microreactors at the similar yield.
基金Supported by the National Natural Science Foundation of China(21376011)the Fundamental Research Foundation of Sinopec(X505015)
文摘For efficient removal of thiophenic sulfur （S-） compounds from oils, a novel method is proposed here, i.e. one-pot alkylation desulfurization （OADS）, in which oil insoluble chlorinated polymer such as polyvinyl chlo- ride （PVC） is used as the alkylating regent with Lewis acid as catalyst. The aromatic S-compounds are grafted to the polymer through Friedel-Crafts reaction and removed facilely along with the polymer. The OADS mechanism is identified by scanning electron microscope and analyzer with surface area and pore size of the polymer. The influ- ence of some factors on the OADS is studied, e.g. the type and amount of chlorinated polymers and Lewis acids. It is nroved that thionhene and benzothioDhene can be removed efficiently from oil by PVC＋AlCl3 mixture even in the presence of 25% （by mass） of benzene due to the synergetic effects of the adsorptive desulfurization of AlCl3 and the alkylation desulfurization of PVC.
文摘The effect of microwave irradiation on the intermolecular and intramolecular Friedel-Crafts acylation of aromatic compounds was investigated. Microwave irradiation had no effect on the intermolecular reaction but had an accelerating effect on the intramolecular reaction. This enhanced intramolecular reactivity that was attributed to the high probability of close proximity between the reaction sites.
文摘The effects to elicit resistance reaction on oilseed rape (Brassica napus L. cv Xinongchangjiao ) by four partially N-acetylated chitosan 7B, 8B, 9B and 10B (Degree of acetylation (D. A.) is 30% , 20% , 10%, 0%, respectively) and Glycol chitosan (GC, D.A. is 0%) were investigated and compared. Results showed that chitosan were similar to salicylic acid (SA), and could induce resistance reaction, but the reaction was influenced by the degree of acetylation of chitosan. Fully deacetylated chitosans, 10B and GC, elicited chitinase activity, but partially acetylated chitosan, 7B, 8B and 9B, inhibited chitinase activity. Phenyalanine ammonia-lyase (PAL) was also elicited. Elicitor activity increased with on increasing degree of acetylation, 7B induced highest PAL activity among all chitosans. All chitosans induced peroxidase (POD) in a similar level. After elicited by glycol chitosan, like SA treatment, the seedlings increased disease resistance to Sclerotinia sclerotiorum significantly.
文摘A mild and efficient method for the conversion of alcohols to their corresponding methoxymethyl ethers and acetates using benzyltriphenylphosphonium tribromide （BTPTB） as catalyst is described. All reactions were performed under completely heterogeneous reaction conditions in good to high yields.
文摘Substituted phenoxy acetyl chloride reacted with trimethyl phosphite to form an unexpected substituted phenoxy acetic acid ester, confirmed by ~1HNMR, IR and MS. The mechanism suggested is different from that of Arbuzov reaction.
文摘The reaction between diphenylmethanols and substituted benzenes is useful to yield triarylmethane derivatives which are important skeletons in various functional materials and biologically relevant substances. The Reactions were carried out under microwave irradiation as environmentally-friendly method. In cyclohexane, the reaction was accelerated under microwave irradiation as compared to under conventional heating. Also, when more than 0.8 equivalents of iron(III) chloride were used, the acceleration was observed. Notably, when iron(III) chloride and arenes were combined, the temperature of the reaction solution rose to 40°C. It is considered that a chemical species was formed upon coordination of iron(III) chloride to the diphenylmethanols or arenes.
文摘Several aromatic ring-substituted N-acetyl-phenylalanine methyl esters were treated with POCl3 in refluxing benzene, which is the typical condition of B-N reaction. It was found that the normal B-N product 3, 4-dihydroisoquinoline-3-carboxylic acid methyl ester and/or 5-benzyl-2-methyl-4-methoxy oxazole could be obtained. The result depended mainly upon the electron-donating property of the substitutes on the benzene ring. Strong electron-donating groups located at para- or ortho- to the cyclization site will facilitate the formation of the normal B-N product 2. On the other hand, the absence or weak electron-donating groups tended to yield the oxazole product 3. It was established that the formation of benzyl oxazole is the competitive path with the B-N reaction. In this article, an explanation was given based on the mechanism of Bishler-Napieralski reaction.
文摘A benzyl oxazole compound 3 was obtained with an excellent yield of 90% when N-acetyl-(2'-methoxy-4',5'-methylenedioxy)-phenylalanine methyl ester 1 was refluxed in POCl1/benzene. However, the anticipated product 3,4-dihydrosioquinoline-3-carboxylic acid methyl ester 2 could not be found. The mechanism was discussed in this article.
基金support from the National Natural Science Foundation of China(No.21871067)the Natural Science Foundation of Guangdong Province(Nos.2018A030313038 and 2021A1515010190)+3 种基金the Shenzhen Fundamental Research Projects(No.JCYJ20180306171838187)the Harbin Institute of Technology(Shenzhen)(Talent Development Starting Fund from Shenzhen Government)the Open Project Program of State Key Laboratory of Elemento-Organic Chemistry(No.202009)the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)。
文摘A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared.The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields(up to 99%) and good to excellent enantioselectivies(up to> 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF_(3)-β-disubstituted nitroalkene was favorable.
基金Study supported by the Science and Technique Foundation of Lanzhou Branch, Academia Sinica.
文摘The present study deals with the study of some Friedel-Crafts alkylating system and the accurate measurement of hyperfine coupling constants by ESR and ENDOR techniques. The results indicate that the observed ESR spectra are due to polycyclic aromatic radical cations formed from their parent hydrocarbons.It is suggested that benzyl halides produced in the Friedel-Crafts alkylating reaction undergo Scholl condensation reaction to give polycyclic aromatic hydrocarbons, which were converted into the corresponding polycyclic aromatic radical cations in the presence of aluminum chloride.
基金the financial support from the Natural Science Foundation of China(No.21772185)National Natural Science Foundation of China(No.22001241)supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)。
文摘A series of pyrazolone derivatives bearing a tetrasubstituted chiral center were prepared by virtue of a Lewis acid-catalyzed Friedel-Crafts reaction,in which a chiral copper complex was employed as the catalyst.This reaction can be carried out smoothly under mild condition to afford the pyrazolone derivatives with high yields(up to 85%)and excellent enantioselectivities(up to 99%).In addition,the gram scale synthesis proved the practicality of this reaction.
基金National Science Foundation of China(No.20702031)Ministry of Science and Technology of China (No.2009CB918404)E-Institutes of Shanghai Universities(EISU) Chemical Biology Division,and National Comprehensive Technology Platforms for Innovative Drug R&D(No.2009ZX09301-007) for financial support of this work
文摘A novel pyrrolo-benzoxaborole,6-（pyrrol-1-yl）-1,3-dihydro-1-hydroxy-2,1-benzoxaborole,was synthesized with 27%overall yield over six steps from 2-bromo-1-methyl-4-nitrobenzene as starting material.Its derivatization was achieved via Friedel-Crafts reaction catalyzed by anhydrous stannic chloride with various acyl chlorides giving 3-acyl-1-phenylpyrroles as the main products.
