Whereas the proper choice of reaction solvent constitutes the cornerstone of the green solvent concept,solvent effects on chemical reactions are not mechanistically well understood due to the lack of feasible molecula...Whereas the proper choice of reaction solvent constitutes the cornerstone of the green solvent concept,solvent effects on chemical reactions are not mechanistically well understood due to the lack of feasible molecular models.Herein,by taking the case study of nucleophilic addition reaction in aqueous solution,we extend the proposed multiscale reaction density functional theory(RxDFT)method to investigate the intrinsic free energy profile and total free energy profile,and study the solvent effect on the activation and reaction free energy for the nucleophilic addition reactions of hydroxide anion with methanal and carbon dioxide in aqueous solution.The predictions of the free energy profile in aqueous solution for these two nucleophilic addition reactions from RxDFT have a satisfactory agreement with the results from the RISM and MD-FEP simulation.Meanwhile,the solvent effect is successfully addressed by examining the difference of the free energy profile between the gas phase and aqueous phase.In addition,we investigate the solvent effect on the reactions occurred near solid-liquid interfaces.It is shown that the activation free energy is significantly depressed when reaction takes place in the region within 10A distance to the substrate surface owing to the decrease of hydration free energy at the solid-liquid interface.展开更多
Synthesis of highly strained tetracyclic ketones was achieved by cyclopropanation or epoxidation of tricyclodecenone 1. An unusual formation of α-methoxy β-hydroxy ketone from an α,β-unsaturated enone system via ...Synthesis of highly strained tetracyclic ketones was achieved by cyclopropanation or epoxidation of tricyclodecenone 1. An unusual formation of α-methoxy β-hydroxy ketone from an α,β-unsaturated enone system via Payne rearrangement was reported.展开更多
The iodine-catalyzed nucleophilic addition reactions of pyrrole, furan, or thiophene with acetone were studied in gas and solvent by the density functional theory at the level of Lanl2DZ^*. It was seen that the halog...The iodine-catalyzed nucleophilic addition reactions of pyrrole, furan, or thiophene with acetone were studied in gas and solvent by the density functional theory at the level of Lanl2DZ^*. It was seen that the halogen bond between iodine and carbonyl oxygen appeared to have an important catalytic effect on such reactions, and the first iodine molecule maximally diminished the barrier height by 41 kJ/mol, while the second iodine molecule could not improve such reactions largely. It was concluded that the C2-addition was generally more favorable than the C3-addition for the three heterocycles; however, iodine considerably more effectively catalyzed the C3-addition than the C2-addition for pyrrole. It was also revealed by PCM calculation that the iodine-catalyzed nucleophilic additions occurred more easily in solvent than in gas, which explained the experiment performed by Bandgar et al..展开更多
Nucleophilic additions to endo-tricyclo[5.2.1.0^(2,6)]deca-2(6),8-dien-3-one 4 are described. Experimental results show high preference for exo-facial attack to the enone moiety of tricyclodecadienone. Steric hindra...Nucleophilic additions to endo-tricyclo[5.2.1.0^(2,6)]deca-2(6),8-dien-3-one 4 are described. Experimental results show high preference for exo-facial attack to the enone moiety of tricyclodecadienone. Steric hindrance is the main kinetically controlling factor in the nucleophilic reaction. The shielding effect and the stabilizing effect of the norbornene double bond favor the exo-facial attack also.展开更多
We studied the cascade nucleophilic addition reactions of 1,2,3-triazines with activated acetonitriles or ketones,which were used to construct highly substituted pyridines that are not easily accessed by conventional ...We studied the cascade nucleophilic addition reactions of 1,2,3-triazines with activated acetonitriles or ketones,which were used to construct highly substituted pyridines that are not easily accessed by conventional methods.The strategy addressed some structural diversity issues currently facing medicinal chemistry,and the resulting pyridines could be used as convenient precursors for the synthesis of related pharmaceuticals.In particular,our method was applied to the syntheses of the marketed drug etoricoxib and several biologically important molecules in a few steps.展开更多
1 Results We have already published a double nucleophilic addition reaction of α,β-unsaturated imines with several nucleophiles such as ketene silyl acetals, trimethylsilyl cyanides, trimethylsilyl azides and thiols...1 Results We have already published a double nucleophilic addition reaction of α,β-unsaturated imines with several nucleophiles such as ketene silyl acetals, trimethylsilyl cyanides, trimethylsilyl azides and thiols[1]. However, it was not easy to use N-allylideneamine 2 derived from acrolein for such reactions. Since there is no substituent at the β-position, imine 2 has high reactivity and are prone to be polymerization. We report the first synthesis of N-allylideneamines 2 using the isomerization of ...展开更多
In the preparation of surface coatings made of conductive composites consisting of conductive particulate fillers in a soft matrix, cracks will develop with increase of the particulate loading, which is believed to be...In the preparation of surface coatings made of conductive composites consisting of conductive particulate fillers in a soft matrix, cracks will develop with increase of the particulate loading, which is believed to be related to the nucleophilic addition reaction between glycidyl end-capped poly (bisphenol A-co-epichlorohydrin) and isophorone diisocyanate molecules. This curing reaction is responsible for the generation of crosslinking network throughout the coatings. The influence of solid particle loading on the chemical reaction may be described as a volume-excluded effect, that is, the high solid particle loading will occupy the space between the functional groups thus preventing the chemical reaction to take place. As a direct consequence, the cross-linking network cannot develop properly due to the insufficiency of curing reaction. This will lead to the generation of cracks, as was supported by FT-IR analysis in this work.展开更多
A novel strategy was developed for the asymmetric synthesis of fluorinated vicinal diamines.Deprotonation of N-(diphenylmethylene)-benzylamines under base,followed by asymmetric nucleophilic addition to N-tert-butanes...A novel strategy was developed for the asymmetric synthesis of fluorinated vicinal diamines.Deprotonation of N-(diphenylmethylene)-benzylamines under base,followed by asymmetric nucleophilic addition to N-tert-butanesulfinylfluoroacetaldimines,a pair of diastereomeric isomers were afforded.The diastereomeric isomers can be easily separated from each other by silica gel column chromatography.The absolute steric configuration of two isomers was confirmed by single crystal X-ray diffraction analyses.The proposed mechanism revealed that the configuration of the carbon next to tert-butanesulfinyl was well controlled to be R by the chiral auxiliary.展开更多
Polyhydroxy enyne compound (+)-(1'S, 2R, 3S, 5S, 6S)-5,6-dimethoxy-5, 6-dimethyl- 2-(1'-hydroxylpropyl-2-ne)-3-vinyl-l,4-dioxane has been synthesized from D-(-)-tartaric acid. A new chiral center was establ...Polyhydroxy enyne compound (+)-(1'S, 2R, 3S, 5S, 6S)-5,6-dimethoxy-5, 6-dimethyl- 2-(1'-hydroxylpropyl-2-ne)-3-vinyl-l,4-dioxane has been synthesized from D-(-)-tartaric acid. A new chiral center was established by nucleophilic addition with 87% de. The modified Mosher's method was employed to confirm the absolute configuration of 17, which assigned the S-configuration at the new chiral center.展开更多
Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are anticipated.In this study,a formal[3+2]method,through the reactions of an o...Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are anticipated.In this study,a formal[3+2]method,through the reactions of an osmapentalyne with benzyl carbanions,was developed.The reactions underwent a nucleophilic attack of carbanions to the Os≡C bond,followed by C—H activation to form the five-membered osmacyclopentadiene ring.Most of the reactions were carried out at room temperature,the substituents on the aromatic rings of benzyl carbanions are diverse,and the resulting products contain an Os—H bond,representing a novel type of 10C-carbolong complexes.This work provides a new convenient route to construct metallacyclopentadienes,which is expected to further promote the development of such a type of substances.展开更多
Atroposelective construction of axially chiral alkene-heteroaryl scaffolds is highly desired but challenging.In this work,we established an atroposelective construction of axially chiral alkene-indole scaffolds via th...Atroposelective construction of axially chiral alkene-heteroaryl scaffolds is highly desired but challenging.In this work,we established an atroposelective construction of axially chiral alkene-indole scaffolds via the strategy of catalytic enantioselective addition reaction of 3-alkynyl-2-indolylmethanols with bulky nucleophiles.展开更多
Under neat conditions,an efficient method for synthesis of imidoesters has been developed using cyanatobenzenes and dicarbonyl compounds.Nucleophilic addition spontaneously occurred between the two kinds of materials ...Under neat conditions,an efficient method for synthesis of imidoesters has been developed using cyanatobenzenes and dicarbonyl compounds.Nucleophilic addition spontaneously occurred between the two kinds of materials at room temperature with yields of up to 90%.A mechanism directed towards to the imidoester formation has been proposed.展开更多
Un der the catalysis of chiral Cu(ll)complex,C2 and C3 alkylati on of pyrrole and C3 alkylation of in dole were realized simulta neously.The chiral oxindole skeleton with an all-carb on quater nary stereogenic cen ter...Un der the catalysis of chiral Cu(ll)complex,C2 and C3 alkylati on of pyrrole and C3 alkylation of in dole were realized simulta neously.The chiral oxindole skeleton with an all-carb on quater nary stereogenic cen ter at the C3-position could be obtai ned exclusively with high yields(up to 95%)and excellent enantioselectivities(up to>99%).展开更多
In the presence of catalytic amount of cesium hydroxide, the hydrothiolation of alkynyl sulfides occurred at room temperature in DMF under nitrogen atmosphere to afford exclusive (Z)-1,2-diorganothio-1-alkene in exc...In the presence of catalytic amount of cesium hydroxide, the hydrothiolation of alkynyl sulfides occurred at room temperature in DMF under nitrogen atmosphere to afford exclusive (Z)-1,2-diorganothio-1-alkene in excellent yields. It could provide a new and expedient way for the preparation of symmetrical and unsymmetrical (Z)-1,2-diorganolthiol-1-alkenes.展开更多
A highly stereoselective synthesis of tetrasubstituted monofluoroalkenes with aldehydes and fluorobis(phenyl- sulfonyl)methane (FBSM) in one pot has been developed. The reaction was amenable topara- and meta-subst...A highly stereoselective synthesis of tetrasubstituted monofluoroalkenes with aldehydes and fluorobis(phenyl- sulfonyl)methane (FBSM) in one pot has been developed. The reaction was amenable topara- and meta-substituted aryl aldehydes, 2-naphthaldehyde, and cinnamaldehyde, giving phenylsulfonyl-substituted monofluoroalkenes in 40%--86% yields with 98/2- 99/1 Z/E ratios. The presence of the sulfonyl group enables the further transformation of the products into more useful monofluoroalkenes.展开更多
A novel hybrid acenaphthene-hemicyanine dye(Acc) was designed and synthesized as a colorimetric and ratiometric fluorescent sensor for cyanide detection. The nucleophilic addition of cyanide anion resulted in the bl...A novel hybrid acenaphthene-hemicyanine dye(Acc) was designed and synthesized as a colorimetric and ratiometric fluorescent sensor for cyanide detection. The nucleophilic addition of cyanide anion resulted in the blocking of the intramolecular charge transfer(ICT). Thus, the sensor exhibited high sensitivity and selectivity to- wards cyanide anion among many anions in dimethylsulphoxide(DMSO)-water media, with the emission wavelength displaying a very large shift(186 nm). Moreover, the color changes of the solution could be observed by the naked eyes and it had a short response time. Under optimized conditions, the detection limit for cyanide was calculated to be 1.3μmol/L(R2=0.9958). In addition, the probe had excellent biocompatibility and could be utilized to monitor cyanide in living cells.展开更多
An efficient and simple synthesis of a-hydroxyphosphonates via reaction of aldehydes and ketones with di- methylphosphite in the presence of MgCI2/Et3N base system is reported. The use of readily available and easy to...An efficient and simple synthesis of a-hydroxyphosphonates via reaction of aldehydes and ketones with di- methylphosphite in the presence of MgCI2/Et3N base system is reported. The use of readily available and easy to handle reagent MgCI2/Et3N makes this method simple, convenient, and practical.展开更多
An efficient method for the hydrocyanation of unsaturated imines to synthesizeβ,γ-unsaturatedα-aminonitriles by a one-pot two-step procedure using potassium hexacyanoferrate(Ⅱ)as a cyanide source and benzoyl chlor...An efficient method for the hydrocyanation of unsaturated imines to synthesizeβ,γ-unsaturatedα-aminonitriles by a one-pot two-step procedure using potassium hexacyanoferrate(Ⅱ)as a cyanide source and benzoyl chloride as a promoter under catalyst-free condition is described.The advantages of this protocol are the use of a nontoxic,nonvolatile and inexpensive cyanating agent,no use of transition metal catalysts,high yield and simple work-up procedure.展开更多
基金supported by National Natural Science Foundation of China(Nos.91934302,21878078 and 21808056)。
文摘Whereas the proper choice of reaction solvent constitutes the cornerstone of the green solvent concept,solvent effects on chemical reactions are not mechanistically well understood due to the lack of feasible molecular models.Herein,by taking the case study of nucleophilic addition reaction in aqueous solution,we extend the proposed multiscale reaction density functional theory(RxDFT)method to investigate the intrinsic free energy profile and total free energy profile,and study the solvent effect on the activation and reaction free energy for the nucleophilic addition reactions of hydroxide anion with methanal and carbon dioxide in aqueous solution.The predictions of the free energy profile in aqueous solution for these two nucleophilic addition reactions from RxDFT have a satisfactory agreement with the results from the RISM and MD-FEP simulation.Meanwhile,the solvent effect is successfully addressed by examining the difference of the free energy profile between the gas phase and aqueous phase.In addition,we investigate the solvent effect on the reactions occurred near solid-liquid interfaces.It is shown that the activation free energy is significantly depressed when reaction takes place in the region within 10A distance to the substrate surface owing to the decrease of hydration free energy at the solid-liquid interface.
文摘Synthesis of highly strained tetracyclic ketones was achieved by cyclopropanation or epoxidation of tricyclodecenone 1. An unusual formation of α-methoxy β-hydroxy ketone from an α,β-unsaturated enone system via Payne rearrangement was reported.
基金the Natural Science Foundation of Zhejiang Province,China(No.Y406374)
文摘The iodine-catalyzed nucleophilic addition reactions of pyrrole, furan, or thiophene with acetone were studied in gas and solvent by the density functional theory at the level of Lanl2DZ^*. It was seen that the halogen bond between iodine and carbonyl oxygen appeared to have an important catalytic effect on such reactions, and the first iodine molecule maximally diminished the barrier height by 41 kJ/mol, while the second iodine molecule could not improve such reactions largely. It was concluded that the C2-addition was generally more favorable than the C3-addition for the three heterocycles; however, iodine considerably more effectively catalyzed the C3-addition than the C2-addition for pyrrole. It was also revealed by PCM calculation that the iodine-catalyzed nucleophilic additions occurred more easily in solvent than in gas, which explained the experiment performed by Bandgar et al..
文摘Nucleophilic additions to endo-tricyclo[5.2.1.0^(2,6)]deca-2(6),8-dien-3-one 4 are described. Experimental results show high preference for exo-facial attack to the enone moiety of tricyclodecadienone. Steric hindrance is the main kinetically controlling factor in the nucleophilic reaction. The shielding effect and the stabilizing effect of the norbornene double bond favor the exo-facial attack also.
基金the financial support from the National Natural Science Foundation of China(No.21772019)Young Elite Scientist Sponsorship Program by CAST(No.2016QNRC001)+2 种基金The Fundamental Research Funds for the Central Universities(No.2019CDQYHG015)The Basic and Frontier Research Project of Chongqing(No.cstc2018jcyj AX0716)The Venture&Innovation Support Program for Chongqing Overseas Returnees(No.cx2019007)。
文摘We studied the cascade nucleophilic addition reactions of 1,2,3-triazines with activated acetonitriles or ketones,which were used to construct highly substituted pyridines that are not easily accessed by conventional methods.The strategy addressed some structural diversity issues currently facing medicinal chemistry,and the resulting pyridines could be used as convenient precursors for the synthesis of related pharmaceuticals.In particular,our method was applied to the syntheses of the marketed drug etoricoxib and several biologically important molecules in a few steps.
文摘1 Results We have already published a double nucleophilic addition reaction of α,β-unsaturated imines with several nucleophiles such as ketene silyl acetals, trimethylsilyl cyanides, trimethylsilyl azides and thiols[1]. However, it was not easy to use N-allylideneamine 2 derived from acrolein for such reactions. Since there is no substituent at the β-position, imine 2 has high reactivity and are prone to be polymerization. We report the first synthesis of N-allylideneamines 2 using the isomerization of ...
文摘In the preparation of surface coatings made of conductive composites consisting of conductive particulate fillers in a soft matrix, cracks will develop with increase of the particulate loading, which is believed to be related to the nucleophilic addition reaction between glycidyl end-capped poly (bisphenol A-co-epichlorohydrin) and isophorone diisocyanate molecules. This curing reaction is responsible for the generation of crosslinking network throughout the coatings. The influence of solid particle loading on the chemical reaction may be described as a volume-excluded effect, that is, the high solid particle loading will occupy the space between the functional groups thus preventing the chemical reaction to take place. As a direct consequence, the cross-linking network cannot develop properly due to the insufficiency of curing reaction. This will lead to the generation of cracks, as was supported by FT-IR analysis in this work.
基金the Innovation Program of Shanghai Municipal Education Commission,China(No.13ZZ047)the Fundamental Research Funds for the Central Universities,China(No.2232015D3-13)
文摘A novel strategy was developed for the asymmetric synthesis of fluorinated vicinal diamines.Deprotonation of N-(diphenylmethylene)-benzylamines under base,followed by asymmetric nucleophilic addition to N-tert-butanesulfinylfluoroacetaldimines,a pair of diastereomeric isomers were afforded.The diastereomeric isomers can be easily separated from each other by silica gel column chromatography.The absolute steric configuration of two isomers was confirmed by single crystal X-ray diffraction analyses.The proposed mechanism revealed that the configuration of the carbon next to tert-butanesulfinyl was well controlled to be R by the chiral auxiliary.
文摘Polyhydroxy enyne compound (+)-(1'S, 2R, 3S, 5S, 6S)-5,6-dimethoxy-5, 6-dimethyl- 2-(1'-hydroxylpropyl-2-ne)-3-vinyl-l,4-dioxane has been synthesized from D-(-)-tartaric acid. A new chiral center was established by nucleophilic addition with 87% de. The modified Mosher's method was employed to confirm the absolute configuration of 17, which assigned the S-configuration at the new chiral center.
基金the NSFC(Nos.22071098,21931002 and 22101123)the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)+2 种基金the Shenzhen Science and Technology Innovation Committee(No.JCYJ20200109140812302)Introduction of Major Talent Projects in Guangdong Province(No.2019CX01C079)Outstanding Talents Training Fund in Shenzhen,for their financial support.
文摘Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are anticipated.In this study,a formal[3+2]method,through the reactions of an osmapentalyne with benzyl carbanions,was developed.The reactions underwent a nucleophilic attack of carbanions to the Os≡C bond,followed by C—H activation to form the five-membered osmacyclopentadiene ring.Most of the reactions were carried out at room temperature,the substituents on the aromatic rings of benzyl carbanions are diverse,and the resulting products contain an Os—H bond,representing a novel type of 10C-carbolong complexes.This work provides a new convenient route to construct metallacyclopentadienes,which is expected to further promote the development of such a type of substances.
基金We are grateful for financial support from the National Natural Science Foundation of China(Nos.21772069 and 21831007)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX20_2235)the Natural Science Foundation of JSNU(No.19XSRX013)。
文摘Atroposelective construction of axially chiral alkene-heteroaryl scaffolds is highly desired but challenging.In this work,we established an atroposelective construction of axially chiral alkene-indole scaffolds via the strategy of catalytic enantioselective addition reaction of 3-alkynyl-2-indolylmethanols with bulky nucleophiles.
基金the National Natural Science Foundation of China (Nos.21372265 and 61271059)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,the Natural Science Foundation Project of CQ CSTC (Nos.CSTC2013jcyjA0217 and CSTC2010BB4086)the Fundamental Research Funds for the Central Universities(Nos.CQDXWL2013-Z012 and CDJZR-14225502)
文摘Under neat conditions,an efficient method for synthesis of imidoesters has been developed using cyanatobenzenes and dicarbonyl compounds.Nucleophilic addition spontaneously occurred between the two kinds of materials at room temperature with yields of up to 90%.A mechanism directed towards to the imidoester formation has been proposed.
文摘Un der the catalysis of chiral Cu(ll)complex,C2 and C3 alkylati on of pyrrole and C3 alkylation of in dole were realized simulta neously.The chiral oxindole skeleton with an all-carb on quater nary stereogenic cen ter at the C3-position could be obtai ned exclusively with high yields(up to 95%)and excellent enantioselectivities(up to>99%).
基金Project supported by the National Natural Science Foundation of China (Nos. 21071152, 20372020).
文摘In the presence of catalytic amount of cesium hydroxide, the hydrothiolation of alkynyl sulfides occurred at room temperature in DMF under nitrogen atmosphere to afford exclusive (Z)-1,2-diorganothio-1-alkene in excellent yields. It could provide a new and expedient way for the preparation of symmetrical and unsymmetrical (Z)-1,2-diorganolthiol-1-alkenes.
基金Acknowledgement Support of our work by the National Natural Science Foundation of China (Nos. 20825209 and 21202189), the National Basic Research Program of China (Nos. 2012CB215500 and 2012CB821600), the Chinese Academy of Sciences, and the Syngenta PhD Studentship (to X.S.) is gratefully acknowledged.
文摘A highly stereoselective synthesis of tetrasubstituted monofluoroalkenes with aldehydes and fluorobis(phenyl- sulfonyl)methane (FBSM) in one pot has been developed. The reaction was amenable topara- and meta-substituted aryl aldehydes, 2-naphthaldehyde, and cinnamaldehyde, giving phenylsulfonyl-substituted monofluoroalkenes in 40%--86% yields with 98/2- 99/1 Z/E ratios. The presence of the sulfonyl group enables the further transformation of the products into more useful monofluoroalkenes.
文摘A novel hybrid acenaphthene-hemicyanine dye(Acc) was designed and synthesized as a colorimetric and ratiometric fluorescent sensor for cyanide detection. The nucleophilic addition of cyanide anion resulted in the blocking of the intramolecular charge transfer(ICT). Thus, the sensor exhibited high sensitivity and selectivity to- wards cyanide anion among many anions in dimethylsulphoxide(DMSO)-water media, with the emission wavelength displaying a very large shift(186 nm). Moreover, the color changes of the solution could be observed by the naked eyes and it had a short response time. Under optimized conditions, the detection limit for cyanide was calculated to be 1.3μmol/L(R2=0.9958). In addition, the probe had excellent biocompatibility and could be utilized to monitor cyanide in living cells.
文摘An efficient and simple synthesis of a-hydroxyphosphonates via reaction of aldehydes and ketones with di- methylphosphite in the presence of MgCI2/Et3N base system is reported. The use of readily available and easy to handle reagent MgCI2/Et3N makes this method simple, convenient, and practical.
基金The authors thank the National Natural Science Foundation of China(Nos.21162024,21362034,21462038)for the financial support of this work.
文摘An efficient method for the hydrocyanation of unsaturated imines to synthesizeβ,γ-unsaturatedα-aminonitriles by a one-pot two-step procedure using potassium hexacyanoferrate(Ⅱ)as a cyanide source and benzoyl chloride as a promoter under catalyst-free condition is described.The advantages of this protocol are the use of a nontoxic,nonvolatile and inexpensive cyanating agent,no use of transition metal catalysts,high yield and simple work-up procedure.