A series of novel Michael addition products of fluorene to chalcone were obtained in the presence of sodium hydroxide under solvent-free condition. The advantages of this procedure were mild reaction conditions, simpl...A series of novel Michael addition products of fluorene to chalcone were obtained in the presence of sodium hydroxide under solvent-free condition. The advantages of this procedure were mild reaction conditions, simple protocol, and high yields. The structures of the products were characterized by IR, 1H NMR, MS and X-ray diffraction. The crystal of the new compound 3 h is Triclinic, space group P-1 with a = 0.97352(6) nm, b = 1.08918(7) nm, c = 2.58418(16) nm, α = 80.1400(10)°, β = 79.5490(10)°, γ = 64.2440(10)°, V = 2.4137(3) nm3, Z = 4, Dc=1.220 g/cm3,μ = 0.286 mm-1, F(000) = 920, R = 0.0656 and wR = 0.1554 for 5664 observed reflection with I 〉 2σ(I).展开更多
An efficient and simple procedure for the synthesis of novel isatin derivatives is described. Michael addition of aniline Schiff bases of isatin or p-toluidine Schiff bases of isatin to fumaric esters affords the Mich...An efficient and simple procedure for the synthesis of novel isatin derivatives is described. Michael addition of aniline Schiff bases of isatin or p-toluidine Schiff bases of isatin to fumaric esters affords the Michael adduct com- pounds in good to high yields in the presence of K2CO3 and tetrabutylammonium bromide (TBAB) under sol- vent-free conditions. Repeating of this reaction about spiro[l,3-dioxolane-2,3'-indol]-2'(l'H)-one, as a Michael do- nor, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) gives Michael adducts in remarkable yields under the same conditions.展开更多
A novel upper-rim functionalized calix[4]squaramide organocatalyst bearing bis-squaramide and cyclohexanediamine scaffolds was designed and prepared to catalyse a serial of asymmetric Michael addition of 1,3-dicarbo n...A novel upper-rim functionalized calix[4]squaramide organocatalyst bearing bis-squaramide and cyclohexanediamine scaffolds was designed and prepared to catalyse a serial of asymmetric Michael addition of 1,3-dicarbo nyl compounds to a,β-unsaturated carbonyl compounds in high yields(up to 99%)and good to excellent enantiomeric excesses(up to 99%ee).The comparative experiments indicated that the cooperative effect between calixarenes cavitives and chiral catalytic centers on this calix[4]squaramide catalyst could promote these reactions.Moreover,this strategy also provides valuable and easy access to chiral chromene,naphthoquinone and acetylacetone derivatives,which are important skeletons in biological and pharmaceutical compounds.展开更多
Two chiral guanidines were evaluated as catalysts for the reaction of anthrone (1) with N-methylmaleimide (2). When guanidine 5 was used, the Michael adduct 4 was isolated as a major product. The best enantioselectivi...Two chiral guanidines were evaluated as catalysts for the reaction of anthrone (1) with N-methylmaleimide (2). When guanidine 5 was used, the Michael adduct 4 was isolated as a major product. The best enantioselectivity (70% ee) was obtained when the reaction was carried out in THF at -20°C.展开更多
Modest to high diastereoselectivites have been observed in the conjugate addition of functionalized alcohols to chiral (E)-nitroalkene 1 depending on the presence of metal catalysts at low tempertwre. The resultS indi...Modest to high diastereoselectivites have been observed in the conjugate addition of functionalized alcohols to chiral (E)-nitroalkene 1 depending on the presence of metal catalysts at low tempertwre. The resultS indicated that the anti-form had been preferred in all cases.展开更多
An enantioselective Michael addition of ethyl 4,4,4-trifluoro-3-oxobutanoate to α,β-unsaturated ketone esters using a chiral alkyl-substituted thiourea catalyst is reported. Excellent levels of stereo-induction (up...An enantioselective Michael addition of ethyl 4,4,4-trifluoro-3-oxobutanoate to α,β-unsaturated ketone esters using a chiral alkyl-substituted thiourea catalyst is reported. Excellent levels of stereo-induction (up to 98% ee) under mild reaction conditions were obtained to afford the corresponding α-trifluoromethyldihydropyrans.展开更多
以β-硝基丙烯酸酯为底物,在无催化剂的条件下与芳胺化合物通过Michael加成反应,高选择性地合成了19个β-硝基-α-氨基丙酸酯类化合物(3a^3s,3i^3s)为新化合物,其结构经1 H NMR,13 C NMR和HR-MS(ESI)表征。并以手性BINOL磷酸为催化剂,...以β-硝基丙烯酸酯为底物,在无催化剂的条件下与芳胺化合物通过Michael加成反应,高选择性地合成了19个β-硝基-α-氨基丙酸酯类化合物(3a^3s,3i^3s)为新化合物,其结构经1 H NMR,13 C NMR和HR-MS(ESI)表征。并以手性BINOL磷酸为催化剂,初步探索了该反应的不对称催化,以85%收率和36%ee合成了产物3g。展开更多
We have developed an iron(III) phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excel...We have developed an iron(III) phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room‐tem‐perature conditions, short reaction time, high yields, simple work‐up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.展开更多
A novel compound of 9-[3-oxo-1-(4-bromopheny)-3-phenypropyl]fluorine (3) was synthesized via nucleophilic addition reaction under solvent-free condition. Its structure was determined by IR, 1H NMR, MS, elemental a...A novel compound of 9-[3-oxo-1-(4-bromopheny)-3-phenypropyl]fluorine (3) was synthesized via nucleophilic addition reaction under solvent-free condition. Its structure was determined by IR, 1H NMR, MS, elemental analysis and X-ray diffraction. The crystal of the new compound is of triclinic system, space group P-1 with a=9.7919(16), b=11.0932(18), c=11.2534(19) , α=76.927(3), β=67.452(3), γ=84.895(3)°, V=1099.7(3) 3, Z=2, Dc=1.369 g/cm3, μ=1.886 mm-1, F(000)=464, R=0.0586 and wR=0.1562 for 3145 observed reflections with Ⅰ 2σ(Ⅰ). π-π Stacking interactions contribute to the stability of the structure.展开更多
文摘A series of novel Michael addition products of fluorene to chalcone were obtained in the presence of sodium hydroxide under solvent-free condition. The advantages of this procedure were mild reaction conditions, simple protocol, and high yields. The structures of the products were characterized by IR, 1H NMR, MS and X-ray diffraction. The crystal of the new compound 3 h is Triclinic, space group P-1 with a = 0.97352(6) nm, b = 1.08918(7) nm, c = 2.58418(16) nm, α = 80.1400(10)°, β = 79.5490(10)°, γ = 64.2440(10)°, V = 2.4137(3) nm3, Z = 4, Dc=1.220 g/cm3,μ = 0.286 mm-1, F(000) = 920, R = 0.0656 and wR = 0.1554 for 5664 observed reflection with I 〉 2σ(I).
文摘An efficient and simple procedure for the synthesis of novel isatin derivatives is described. Michael addition of aniline Schiff bases of isatin or p-toluidine Schiff bases of isatin to fumaric esters affords the Michael adduct com- pounds in good to high yields in the presence of K2CO3 and tetrabutylammonium bromide (TBAB) under sol- vent-free conditions. Repeating of this reaction about spiro[l,3-dioxolane-2,3'-indol]-2'(l'H)-one, as a Michael do- nor, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) gives Michael adducts in remarkable yields under the same conditions.
基金the financial support from the National Natural Science Foundation of China(Nos.21572026 and 21702019)Advanced Catalysis and Green Manufacturing Collabo-rative Innovation Center,Changzhou University,and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘A novel upper-rim functionalized calix[4]squaramide organocatalyst bearing bis-squaramide and cyclohexanediamine scaffolds was designed and prepared to catalyse a serial of asymmetric Michael addition of 1,3-dicarbo nyl compounds to a,β-unsaturated carbonyl compounds in high yields(up to 99%)and good to excellent enantiomeric excesses(up to 99%ee).The comparative experiments indicated that the cooperative effect between calixarenes cavitives and chiral catalytic centers on this calix[4]squaramide catalyst could promote these reactions.Moreover,this strategy also provides valuable and easy access to chiral chromene,naphthoquinone and acetylacetone derivatives,which are important skeletons in biological and pharmaceutical compounds.
基金Project supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China (grant No. 29725205).
文摘Two chiral guanidines were evaluated as catalysts for the reaction of anthrone (1) with N-methylmaleimide (2). When guanidine 5 was used, the Michael adduct 4 was isolated as a major product. The best enantioselectivity (70% ee) was obtained when the reaction was carried out in THF at -20°C.
文摘Modest to high diastereoselectivites have been observed in the conjugate addition of functionalized alcohols to chiral (E)-nitroalkene 1 depending on the presence of metal catalysts at low tempertwre. The resultS indicated that the anti-form had been preferred in all cases.
基金Project supported by the National Natural Science Foundation of China (No. 21032006).
文摘An enantioselective Michael addition of ethyl 4,4,4-trifluoro-3-oxobutanoate to α,β-unsaturated ketone esters using a chiral alkyl-substituted thiourea catalyst is reported. Excellent levels of stereo-induction (up to 98% ee) under mild reaction conditions were obtained to afford the corresponding α-trifluoromethyldihydropyrans.
文摘以β-硝基丙烯酸酯为底物,在无催化剂的条件下与芳胺化合物通过Michael加成反应,高选择性地合成了19个β-硝基-α-氨基丙酸酯类化合物(3a^3s,3i^3s)为新化合物,其结构经1 H NMR,13 C NMR和HR-MS(ESI)表征。并以手性BINOL磷酸为催化剂,初步探索了该反应的不对称催化,以85%收率和36%ee合成了产物3g。
基金supported by the Industrial Research Project of Shaanxi Science and Technology Department(2014K08-29)Science and Technology Plan Project of Xi’an(CXY1511(7))Scientific Research Foundation of Northwest University~~
文摘We have developed an iron(III) phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room‐tem‐perature conditions, short reaction time, high yields, simple work‐up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.
基金Supported by the Team Research for Excellent Mid-aged and Young Teachers of Higher Education of Hubei Province (T200707)
文摘A novel compound of 9-[3-oxo-1-(4-bromopheny)-3-phenypropyl]fluorine (3) was synthesized via nucleophilic addition reaction under solvent-free condition. Its structure was determined by IR, 1H NMR, MS, elemental analysis and X-ray diffraction. The crystal of the new compound is of triclinic system, space group P-1 with a=9.7919(16), b=11.0932(18), c=11.2534(19) , α=76.927(3), β=67.452(3), γ=84.895(3)°, V=1099.7(3) 3, Z=2, Dc=1.369 g/cm3, μ=1.886 mm-1, F(000)=464, R=0.0586 and wR=0.1562 for 3145 observed reflections with Ⅰ 2σ(Ⅰ). π-π Stacking interactions contribute to the stability of the structure.