Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated. The results proved that...Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated. The results proved that both cinnamaldehyde and benzalacetone had an evident anticorrosion effect and could reduce the corrosion of steel effectively in acid medium, α,β-unsaturated carbonyl compounds with a benzene ring structure had good adsorption on steel surface. The experiments proved that polymerization of α,β-unsaturated carbonyl compounds on the steel surface at a high temperature and in concentrated acid medium resulted in a good corrosion inhibiting effect, which was attributed to the structures of α,β-unsaturated carbonyl compounds.展开更多
Emissions of volatile organic compounds （VOCs） and carbonyls from residential coal combustion of five coals with different maturities were studied in a simulated room.The coals were burned in form of honeycomb briqu...Emissions of volatile organic compounds （VOCs） and carbonyls from residential coal combustion of five coals with different maturities were studied in a simulated room.The coals were burned in form of honeycomb briquettes in a domestic coal stove,one of the most common fuel/stove combinations in China.Through a dilution system,VOCs and carbonyls samples were collected by canisters and silica-gel cartridges and analyzed by gas chromatography and mass spectrum （GC/MS） and high performance liquid chromatography/ultraviolet （HPLC/UV）,respectively.The results show that the bituminous coals with medium volatile matter content produce the highest emissions while the anthracite yields the lowest.Among the identified carbonyls from the coal smoke,the aromatic compounds （benzaldehyde,2,5-dimethylbenzaldehyde and p-tolualdehyde,m/o-tolualdehyde,benzene,m,p-xylene and trimethyl-benzene） were relatively abundant,which might be due to the molecular structure of the coal.For formaldehyde,aromatic carbonyls and aliphatic alkanes,their concentrations increase up to the maximum values and then decrease with increasing coal maturity.The total carbonyls and VOCs have the same tendency,which was observed for the emission factors of organic carbon （OC）,elemental carbon （EC）,particulate matter （PM） and polycyclic aromatic hydrocarbons （PAHs） detected in the series study.展开更多
Oxathioacetalyzation of carbonyl compounds with 2-mercaptoethanol and deprotection of the obtained 1,3-oxathiolanes is easily performed in the presence of silica sulfuric acid （SSA）. All reactions were performed und...Oxathioacetalyzation of carbonyl compounds with 2-mercaptoethanol and deprotection of the obtained 1,3-oxathiolanes is easily performed in the presence of silica sulfuric acid （SSA）. All reactions were performed under mild and completely heterogeneous reaction conditions in good to high yields.展开更多
[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separa...[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.展开更多
In the presence of copper （I） halide as catalyst, a variety of carbonyl compounds could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields.
Michael addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of KF/AI_2O_3/PEG4000 without solvent.Yields are fair to good and work-ups are easy.
The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with...The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with highfraxnework Si/A1 ratio was proven to be suitable cataipst for the acetabotion ofunsaturated carbonyl compounds, during which the C =C double bond was notperturbed展开更多
In this paper, a new HPLC method was established to determine the carbonyl compounds in air. As the absorbent, 2, 4-dinitrophenylhydrazine (2, 4-DNPH) reacted with carbonyls specifically, which form the corresponding...In this paper, a new HPLC method was established to determine the carbonyl compounds in air. As the absorbent, 2, 4-dinitrophenylhydrazine (2, 4-DNPH) reacted with carbonyls specifically, which form the corresponding 2,4-dinitrophenylhydrazones, then analyzed by HPLC. The chromatographic conditions, the recovery rate, stability of samples, reagent blank, sampling efficiency were all studied systematically. The results showed that this established method had high sensitivity and good selectivity compared with other analytical methods, and it can determine ten carbonyl compounds in air in 26 min simultaneously.展开更多
The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl...The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl·2THF with NaH in THF reacts with unsaturated carbonyl compounds to give the corresponding reduction products with a high selectivity. The carbonyl groups have been reduced while the carbon-carbon double bonds are not affected.展开更多
The\dDDe)Rhly --CU)Zjw(CO)3(jab--Cr,ilo,W)heterobinuclear m,t'1carbonyl c ompQunds were synthesized and characterized by ic and h Iljlh'Their catalytic activit ies for CO hydrogecation were determined.
Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic...Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.展开更多
This paper reports a new method for oxidizing the α-methyl or α-methylene groups in carbonyl compounds into 1,2-dicarbonyl compounds by ammonium chlorochromate(ACC).
In the presence of CrC13 /Fe bimetal couple,per(poly)fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.
A new solvent free method for protection of carbonyl compounds as their thioacetals has been accomplished through the use of iodine supported on nanostructured pyrophosphate. Advantages of the methodology include very...A new solvent free method for protection of carbonyl compounds as their thioacetals has been accomplished through the use of iodine supported on nanostructured pyrophosphate. Advantages of the methodology include very short reaction time, the requirement for minimum amounts of catalyst, the remarkably simple experimental procedure, and no necessity for solvents or inert atmospheres, excellent yields and recyclability of the catalyst used. An efficient method for the chemoselective thioacetalization of ketones in the presence of aldehydes using I2/nanostructured pyrophosphate is also reported in this article. The nanostructured pyrophosphate was characterized by scanning electron microscopy, X-ray diffraction, infrared spectroscopy, Transmission electron microscopy and thermal gravimetric analysis, respectively.展开更多
In our study on the chemistry of ZrCl_4-NaBH_4,we have found that aldehydes and ketones can be regenerated from acetals and ketals at 30℃ in Et_2O in high yield The reaction mechanism was discussed.
α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cycli...α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.展开更多
文摘Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated. The results proved that both cinnamaldehyde and benzalacetone had an evident anticorrosion effect and could reduce the corrosion of steel effectively in acid medium, α,β-unsaturated carbonyl compounds with a benzene ring structure had good adsorption on steel surface. The experiments proved that polymerization of α,β-unsaturated carbonyl compounds on the steel surface at a high temperature and in concentrated acid medium resulted in a good corrosion inhibiting effect, which was attributed to the structures of α,β-unsaturated carbonyl compounds.
基金supported by the National Natural Science Foundation of China (Grant Nos.40773047,40605033 and 40973071)the Shanghai Leading Academic Discipline Project (Grant No.S30109)the Earmarked Foundation of the State Key Laboratory of Organic Geochemistry (Grant No.OGL-200705)
文摘Emissions of volatile organic compounds （VOCs） and carbonyls from residential coal combustion of five coals with different maturities were studied in a simulated room.The coals were burned in form of honeycomb briquettes in a domestic coal stove,one of the most common fuel/stove combinations in China.Through a dilution system,VOCs and carbonyls samples were collected by canisters and silica-gel cartridges and analyzed by gas chromatography and mass spectrum （GC/MS） and high performance liquid chromatography/ultraviolet （HPLC/UV）,respectively.The results show that the bituminous coals with medium volatile matter content produce the highest emissions while the anthracite yields the lowest.Among the identified carbonyls from the coal smoke,the aromatic compounds （benzaldehyde,2,5-dimethylbenzaldehyde and p-tolualdehyde,m/o-tolualdehyde,benzene,m,p-xylene and trimethyl-benzene） were relatively abundant,which might be due to the molecular structure of the coal.For formaldehyde,aromatic carbonyls and aliphatic alkanes,their concentrations increase up to the maximum values and then decrease with increasing coal maturity.The total carbonyls and VOCs have the same tendency,which was observed for the emission factors of organic carbon （OC）,elemental carbon （EC）,particulate matter （PM） and polycyclic aromatic hydrocarbons （PAHs） detected in the series study.
文摘Oxathioacetalyzation of carbonyl compounds with 2-mercaptoethanol and deprotection of the obtained 1,3-oxathiolanes is easily performed in the presence of silica sulfuric acid （SSA）. All reactions were performed under mild and completely heterogeneous reaction conditions in good to high yields.
基金support from Nanjing University of Science and Technology
文摘[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.
文摘In the presence of copper （I） halide as catalyst, a variety of carbonyl compounds could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields.
文摘Michael addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of KF/AI_2O_3/PEG4000 without solvent.Yields are fair to good and work-ups are easy.
文摘The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with highfraxnework Si/A1 ratio was proven to be suitable cataipst for the acetabotion ofunsaturated carbonyl compounds, during which the C =C double bond was notperturbed
文摘In this paper, a new HPLC method was established to determine the carbonyl compounds in air. As the absorbent, 2, 4-dinitrophenylhydrazine (2, 4-DNPH) reacted with carbonyls specifically, which form the corresponding 2,4-dinitrophenylhydrazones, then analyzed by HPLC. The chromatographic conditions, the recovery rate, stability of samples, reagent blank, sampling efficiency were all studied systematically. The results showed that this established method had high sensitivity and good selectivity compared with other analytical methods, and it can determine ten carbonyl compounds in air in 26 min simultaneously.
文摘The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl·2THF with NaH in THF reacts with unsaturated carbonyl compounds to give the corresponding reduction products with a high selectivity. The carbonyl groups have been reduced while the carbon-carbon double bonds are not affected.
文摘The\dDDe)Rhly --CU)Zjw(CO)3(jab--Cr,ilo,W)heterobinuclear m,t'1carbonyl c ompQunds were synthesized and characterized by ic and h Iljlh'Their catalytic activit ies for CO hydrogecation were determined.
文摘Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.
基金The Project Supported by National Science Foundation of China.
文摘This paper reports a new method for oxidizing the α-methyl or α-methylene groups in carbonyl compounds into 1,2-dicarbonyl compounds by ammonium chlorochromate(ACC).
文摘In the presence of CrC13 /Fe bimetal couple,per(poly)fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.
文摘A new solvent free method for protection of carbonyl compounds as their thioacetals has been accomplished through the use of iodine supported on nanostructured pyrophosphate. Advantages of the methodology include very short reaction time, the requirement for minimum amounts of catalyst, the remarkably simple experimental procedure, and no necessity for solvents or inert atmospheres, excellent yields and recyclability of the catalyst used. An efficient method for the chemoselective thioacetalization of ketones in the presence of aldehydes using I2/nanostructured pyrophosphate is also reported in this article. The nanostructured pyrophosphate was characterized by scanning electron microscopy, X-ray diffraction, infrared spectroscopy, Transmission electron microscopy and thermal gravimetric analysis, respectively.
文摘In our study on the chemistry of ZrCl_4-NaBH_4,we have found that aldehydes and ketones can be regenerated from acetals and ketals at 30℃ in Et_2O in high yield The reaction mechanism was discussed.
基金We gratefully acknowledge financial support from the National Science of Foundation of China(81960631)the Yunnan Fundamental Research Project(202001AS070038)+1 种基金the Top Young Talent of Ten Thousand Talents Program of Yunnan Province(R.Zhan and L.-D Shao)the Start-up Fund of Yunnan University of Chinese Medicine(2019YZG03).
文摘α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.
