Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ...Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.展开更多
Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was w...Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was worth noting that the catalyst exhibited extremely high activity. The reduction could be completed within 20-50 min and the yields were up to 97-99 %.展开更多
Aromatic nitro compounds were reduced to the corresponding anilines by refluxing with potassium selenated borohydride (KBH2Se3) prepared from potassium borohydride and selenium in refluxed formamide.
An unusual reduction of some aromatic aldehydes and ketones by sodium borohydride was discovered.In a THF/H2O or DMSO/H2O solvent system the aromatic aldehydes and ketones with acyloxy substituent on the orthoposition...An unusual reduction of some aromatic aldehydes and ketones by sodium borohydride was discovered.In a THF/H2O or DMSO/H2O solvent system the aromatic aldehydes and ketones with acyloxy substituent on the orthoposition to the carbonyl group can be reduced to the corresponding alkyl phenols.This unusual reduction is applicable also to the corresponding alcohols of all the above aldehydes and ketones.A putative mechanism was suggested.In addition to the above aldehydes,ketones and benzyl alcohols,certain 4acyloxybenzyl esters(probably also the 2substituted analogues)such as 4benzoyloxybenzyl benzoate was also found to be reduced to methylphenol by this unusual reduction.展开更多
The reagent combination of Hantzsch 1,4-dihydropyridine and Pd/C was found to be an efficient reducing system for the selective reduction of aromatic azides.
Two aromatic aldehydes are found to be reduced by an unusual way by sodium borohydride in the presence of water to yield the corresponding methyl substituted aryl compounds.
In the synthesis of l-phenyl-5-substituted amino-4-pyrazole N-alkyl amide, it was found for the first time that one of the two aromatic amido groups in the molecule of 1-phenyl-5-benzoyl amino-4-pyrazole N-alkyl amide...In the synthesis of l-phenyl-5-substituted amino-4-pyrazole N-alkyl amide, it was found for the first time that one of the two aromatic amido groups in the molecule of 1-phenyl-5-benzoyl amino-4-pyrazole N-alkyl amide was reduced selectively by LiAlH_4. new conclusion was drawn after several experiments have been done that ortho-amino(or substituted amino)aryl amide or the aryl amide with its ortho substituent which can be reduced into an amino group(or substituted amino group)can not be reduced by LiAlH_4. It was further rationalized by quantum chemical calculation.展开更多
The asymmetric borane reduction of carbonyl compounds using chiral catalysts is one of the most active research. Among them,Oxazaborolidines developed by Corey are most significant- Herein. we report the use of sufony...The asymmetric borane reduction of carbonyl compounds using chiral catalysts is one of the most active research. Among them,Oxazaborolidines developed by Corey are most significant- Herein. we report the use of sufonylamides as chiral catalysts to reduce aromatic ketone in high yield and with e.e. of up to 91 %. Scheme:展开更多
Nitroaromatic compounds were reductively metabolized to the corresponding amine compounds via the intermediate hydroxylamines by liver microsomes from pig,rat,chook,cattle,sheep,paralichthys olivaceus and cyprinoid in...Nitroaromatic compounds were reductively metabolized to the corresponding amine compounds via the intermediate hydroxylamines by liver microsomes from pig,rat,chook,cattle,sheep,paralichthys olivaceus and cyprinoid in varied reactivity.Similar with baker＇s yeast,the pig,rat and sheep liver microsomes exhibited high reactivity toward 4-nitro-1,2-dicyanbenzen（1a）,while the cyprinoid liver microsomes were inefficient.Contrasted to compound 1a,monocyannitrobenzene（2a） was difficult to reduce by pig liver microsomes.In opposition to grape cells,pig liver microsomes exhibited activities toward some aromatic hydroxylamine compounds.展开更多
Nanoparticles have properties that can be fine-tuned by their size as well as shape.Hence,there is significant current interest in preparing nano-materials of small size dispersity and to arrange them in close-packed ...Nanoparticles have properties that can be fine-tuned by their size as well as shape.Hence,there is significant current interest in preparing nano-materials of small size dispersity and to arrange them in close-packed aggregates.This letter describes a way of synthesising silver nanoparticles and their protection to aggregate by silica gel.The combination of catalytic quantities of immobilized silver nanoparticles with reductive ability of NaBH_4 efficiently reduces aromatic nitroarenes to the corresponding amines in aqueous medium.Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogen and carboxylic acid groups.The silver particles immobilized on silica gel are stable in the presence of oxygen for several months.展开更多
bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China The differently substituted aromatic nitro compounds were chemoselect...bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China The differently substituted aromatic nitro compounds were chemoselectively reduced by Sm/HOAc system in an ionic liquid medium to afford aromatic amines. Under these conditions the other substituents, such as -X, -CHO, -COOH, -CN, -NHTos and -alkyl, remained intact. The notable advantages of this reaction are its mild conditions, simple operation, short reaction time, high yields and easy recycling of ionic liquid.展开更多
Asymmetric reduction of ct-hydroxy aromatic ketones was carded out by using carrot enzymes system, yielding corresponding chiral vicinal diols with special functional groups. The optimum reaction conditions were obtai...Asymmetric reduction of ct-hydroxy aromatic ketones was carded out by using carrot enzymes system, yielding corresponding chiral vicinal diols with special functional groups. The optimum reaction conditions were obtained after investigation of various influencing factors. Chiral aryl vicinal diols were produced with good yields and excellent enantiomeric excesses under appropriate conditions. Meanwhile, the steric factors and electronic effects of the substituents on the aromatic ring were shown to have an interesting influence on both yield and enantioselectivity.展开更多
Two after treatment units, selective catalytic reduction （SCR） and continuously regenerating trap （CRT）, were independently retrofitted to a diesel engine, with the objective to investigate their impact on the con...Two after treatment units, selective catalytic reduction （SCR） and continuously regenerating trap （CRT）, were independently retrofitted to a diesel engine, with the objective to investigate their impact on the conversion/reduction （CR） of polycyclic aromatic hydrocarbons （PAHs）. The experiments were conducted under the European steady state cycle （ESC） first without any retrofits to get baseline emissions, and then with SCR and CRT respectively, on the same engine. The particulate matter （PM）-phase PAHs were trapped in fiberglass filters, whereas gas-phase PAHs were collected in cartridges, and then analyzed using a gas chromatograph-mass spectrometer （GC-MS）. Both PM-phase and gas-phase PAHs were greatly reduced with CRT showing respective CR of 90.7% and above 80%, whereas only gas-phase PAHs were abated in the case of SCR, with CR of above 75%. Lower molecular weight （LMW） PAHs were in abundance, while naphthalene exhibited a maximum relative contribution （RC） to LMW-PAHs for all three cases. Further, the CR of naphthalene and anthracene were increased with increasing catalyst temperature of SCR, most likely due to their conversion to solid particles. Moreover, the Benzo[a]Pyrene equivalent （BaPeq） of PAHs was greatly reduced with CRT, owing to substantial reduction of total PAHs.展开更多
文摘Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.
文摘Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was worth noting that the catalyst exhibited extremely high activity. The reduction could be completed within 20-50 min and the yields were up to 97-99 %.
文摘Aromatic nitro compounds were reduced to the corresponding anilines by refluxing with potassium selenated borohydride (KBH2Se3) prepared from potassium borohydride and selenium in refluxed formamide.
文摘An unusual reduction of some aromatic aldehydes and ketones by sodium borohydride was discovered.In a THF/H2O or DMSO/H2O solvent system the aromatic aldehydes and ketones with acyloxy substituent on the orthoposition to the carbonyl group can be reduced to the corresponding alkyl phenols.This unusual reduction is applicable also to the corresponding alcohols of all the above aldehydes and ketones.A putative mechanism was suggested.In addition to the above aldehydes,ketones and benzyl alcohols,certain 4acyloxybenzyl esters(probably also the 2substituted analogues)such as 4benzoyloxybenzyl benzoate was also found to be reduced to methylphenol by this unusual reduction.
基金the National Natural Science Foundation of China(No.20772053)Natural Science Foundation of Gansu Province(No.3ZS061-A25-004)for financial support.
文摘The reagent combination of Hantzsch 1,4-dihydropyridine and Pd/C was found to be an efficient reducing system for the selective reduction of aromatic azides.
文摘Two aromatic aldehydes are found to be reduced by an unusual way by sodium borohydride in the presence of water to yield the corresponding methyl substituted aryl compounds.
基金Project supported by National Natural Science Foundation of China.
文摘In the synthesis of l-phenyl-5-substituted amino-4-pyrazole N-alkyl amide, it was found for the first time that one of the two aromatic amido groups in the molecule of 1-phenyl-5-benzoyl amino-4-pyrazole N-alkyl amide was reduced selectively by LiAlH_4. new conclusion was drawn after several experiments have been done that ortho-amino(or substituted amino)aryl amide or the aryl amide with its ortho substituent which can be reduced into an amino group(or substituted amino group)can not be reduced by LiAlH_4. It was further rationalized by quantum chemical calculation.
文摘The asymmetric borane reduction of carbonyl compounds using chiral catalysts is one of the most active research. Among them,Oxazaborolidines developed by Corey are most significant- Herein. we report the use of sufonylamides as chiral catalysts to reduce aromatic ketone in high yield and with e.e. of up to 91 %. Scheme:
基金Supported by the National Basic Research Program of China(No.2009CB724706)the National Natural Science Foundation of China(No.20876025)
文摘Nitroaromatic compounds were reductively metabolized to the corresponding amine compounds via the intermediate hydroxylamines by liver microsomes from pig,rat,chook,cattle,sheep,paralichthys olivaceus and cyprinoid in varied reactivity.Similar with baker＇s yeast,the pig,rat and sheep liver microsomes exhibited high reactivity toward 4-nitro-1,2-dicyanbenzen（1a）,while the cyprinoid liver microsomes were inefficient.Contrasted to compound 1a,monocyannitrobenzene（2a） was difficult to reduce by pig liver microsomes.In opposition to grape cells,pig liver microsomes exhibited activities toward some aromatic hydroxylamine compounds.
基金supports for this work by Shahid Chamran University Research Council
文摘Nanoparticles have properties that can be fine-tuned by their size as well as shape.Hence,there is significant current interest in preparing nano-materials of small size dispersity and to arrange them in close-packed aggregates.This letter describes a way of synthesising silver nanoparticles and their protection to aggregate by silica gel.The combination of catalytic quantities of immobilized silver nanoparticles with reductive ability of NaBH_4 efficiently reduces aromatic nitroarenes to the corresponding amines in aqueous medium.Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogen and carboxylic acid groups.The silver particles immobilized on silica gel are stable in the presence of oxygen for several months.
基金theNationalNaturalScienceFoundationofChina (No .2 9872 0 10 )theNaturalScienceFoundationofZhejiangProvinceChina (No .2 0 0 72 0 33)
文摘bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China The differently substituted aromatic nitro compounds were chemoselectively reduced by Sm/HOAc system in an ionic liquid medium to afford aromatic amines. Under these conditions the other substituents, such as -X, -CHO, -COOH, -CN, -NHTos and -alkyl, remained intact. The notable advantages of this reaction are its mild conditions, simple operation, short reaction time, high yields and easy recycling of ionic liquid.
基金supported by the National Natural Science Foundation of China(No.21176203)the National Special Fund for State Key Laboratory of Bioreactor Engineering(No.2060204)the Fundamental Research Funds for the Central Universities(No.JUSRP211A12)
文摘Asymmetric reduction of ct-hydroxy aromatic ketones was carded out by using carrot enzymes system, yielding corresponding chiral vicinal diols with special functional groups. The optimum reaction conditions were obtained after investigation of various influencing factors. Chiral aryl vicinal diols were produced with good yields and excellent enantiomeric excesses under appropriate conditions. Meanwhile, the steric factors and electronic effects of the substituents on the aromatic ring were shown to have an interesting influence on both yield and enantioselectivity.
基金supported by the National Natural Science Foundation of China (No. 50876013)
文摘Two after treatment units, selective catalytic reduction （SCR） and continuously regenerating trap （CRT）, were independently retrofitted to a diesel engine, with the objective to investigate their impact on the conversion/reduction （CR） of polycyclic aromatic hydrocarbons （PAHs）. The experiments were conducted under the European steady state cycle （ESC） first without any retrofits to get baseline emissions, and then with SCR and CRT respectively, on the same engine. The particulate matter （PM）-phase PAHs were trapped in fiberglass filters, whereas gas-phase PAHs were collected in cartridges, and then analyzed using a gas chromatograph-mass spectrometer （GC-MS）. Both PM-phase and gas-phase PAHs were greatly reduced with CRT showing respective CR of 90.7% and above 80%, whereas only gas-phase PAHs were abated in the case of SCR, with CR of above 75%. Lower molecular weight （LMW） PAHs were in abundance, while naphthalene exhibited a maximum relative contribution （RC） to LMW-PAHs for all three cases. Further, the CR of naphthalene and anthracene were increased with increasing catalyst temperature of SCR, most likely due to their conversion to solid particles. Moreover, the Benzo[a]Pyrene equivalent （BaPeq） of PAHs was greatly reduced with CRT, owing to substantial reduction of total PAHs.
