Asymmetric pinacol coupling of aromatic aldehydes catalyzed by chiral diamines/low valent titanium complexes gave corresponding pinacols in good yields with high diastereoselectivity and moderate enantioselectivities.
The use of chiral organophosphoras derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The ...The use of chiral organophosphoras derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The method is accurate, reliable and convenient.展开更多
A highly efficient catalytic system composed of a simple and commercially available chiral primary diamine（1R,2R）-cyclohexane-1,2-diamine（6） and trifluoroacetic acid（TFA） was employed for asymmetric Aldol reacti...A highly efficient catalytic system composed of a simple and commercially available chiral primary diamine（1R,2R）-cyclohexane-1,2-diamine（6） and trifluoroacetic acid（TFA） was employed for asymmetric Aldol reaction in i-PrOH at room temperature.A loading of 10%（molar fraction） catalyst 6 with TFA as a cocatalyst could catalyze the Aldol reactions of various ketones or aldehydes with a series of aromatic aldehydes,furnishing Aldol products in moderate to high yields（up to 99%） with enantioselectivities of up to 99% and diastereoselectivities of up to 99：1.展开更多
A series of new platinum（II） complexes with C2-asymmetric and C2-symmetric 1,2-diamines were designed and synthesized by convenient methods, involving samarium diiodide induced reductive coupling as the key step. Th...A series of new platinum（II） complexes with C2-asymmetric and C2-symmetric 1,2-diamines were designed and synthesized by convenient methods, involving samarium diiodide induced reductive coupling as the key step. The results of cytotoxicity showed that compounds （R,R）-lla and （S,S）-lla, two novel platinum（II） complexes with asymmetric 1,2-diamines, exhibited more potent cytotoxicity than that of oxaliplatin against all leukemia cell lines. Interestingly, （R,R）-lla and （S,S）-lla demonstrated less potent activity against three solid cancer cell lines than that of oxaliplatin, which indicated that these two compounds may only selectively inhibit the leukemia cell lines. In contrast, （R,R）-ISa and （S,S）-15a, two platinum（II） complexes with symmetric 1,2-diamines, showed similar cyto- toxicity to that of oxaliplatin against all leukemia cell lines and more potent activity against solid cancer cell lines. Further flow cytometry data indicated that （R,R）-lla could obviously arrest leukemia K562 cells in G2/M phases.展开更多
The first asymmetric hydrogenation of unfunctionalized 2-substituted and 2,3-disubstituted 5,6-dihydropyrazines catalyzed by chiral cationic Ru-diamine complex(R,R)-1a was developed,affording chiral piperazine derivat...The first asymmetric hydrogenation of unfunctionalized 2-substituted and 2,3-disubstituted 5,6-dihydropyrazines catalyzed by chiral cationic Ru-diamine complex(R,R)-1a was developed,affording chiral piperazine derivatives with good enantioselectivities(up to 89% ee).展开更多
Chiral N,N＇-dialkylated cyclohexanediamine derived ligands have been synthesized and used in the asymmetric hydrogenation of aryl ketones.Optically active alcohols with up to 90%enantiomeric excess were obtained in h...Chiral N,N＇-dialkylated cyclohexanediamine derived ligands have been synthesized and used in the asymmetric hydrogenation of aryl ketones.Optically active alcohols with up to 90%enantiomeric excess were obtained in high yields.展开更多
The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugate...The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.展开更多
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 9872 0 3 5 )
文摘Asymmetric pinacol coupling of aromatic aldehydes catalyzed by chiral diamines/low valent titanium complexes gave corresponding pinacols in good yields with high diastereoselectivity and moderate enantioselectivities.
文摘The use of chiral organophosphoras derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The method is accurate, reliable and convenient.
基金Supported by the National Basic Research Program of China(No.2010CB833300)the Research Fund for the Doctoral Program of Higher Education,China(No.20090031110019)
文摘A highly efficient catalytic system composed of a simple and commercially available chiral primary diamine（1R,2R）-cyclohexane-1,2-diamine（6） and trifluoroacetic acid（TFA） was employed for asymmetric Aldol reaction in i-PrOH at room temperature.A loading of 10%（molar fraction） catalyst 6 with TFA as a cocatalyst could catalyze the Aldol reactions of various ketones or aldehydes with a series of aromatic aldehydes,furnishing Aldol products in moderate to high yields（up to 99%） with enantioselectivities of up to 99% and diastereoselectivities of up to 99：1.
基金Acknowledgement Financial support by the National Natural Science Foundation of China （No. 81172920）, the Shanghai Municipal Committee of Science and Technology （No. 10431903100）, and the National Basic Research Pro- gram of China （973 Program, No. 2010CB912603） are acknowledged. We would like to thank Prof. G.-Q. Lin for the guidance of asymmetric synthesis.
文摘A series of new platinum（II） complexes with C2-asymmetric and C2-symmetric 1,2-diamines were designed and synthesized by convenient methods, involving samarium diiodide induced reductive coupling as the key step. The results of cytotoxicity showed that compounds （R,R）-lla and （S,S）-lla, two novel platinum（II） complexes with asymmetric 1,2-diamines, exhibited more potent cytotoxicity than that of oxaliplatin against all leukemia cell lines. Interestingly, （R,R）-lla and （S,S）-lla demonstrated less potent activity against three solid cancer cell lines than that of oxaliplatin, which indicated that these two compounds may only selectively inhibit the leukemia cell lines. In contrast, （R,R）-ISa and （S,S）-15a, two platinum（II） complexes with symmetric 1,2-diamines, showed similar cyto- toxicity to that of oxaliplatin against all leukemia cell lines and more potent activity against solid cancer cell lines. Further flow cytometry data indicated that （R,R）-lla could obviously arrest leukemia K562 cells in G2/M phases.
基金We thank the National Natural Science Foundation of China(Grant No.21232008)National Basic Research Program of China(973 Program,2010CB-833300),Foundation for University Youth Key Teacher of Henan Province(2013GGJS-207)and the Chinese Academy of Sciences(CMS-PY-201303)for financial supports.
文摘The first asymmetric hydrogenation of unfunctionalized 2-substituted and 2,3-disubstituted 5,6-dihydropyrazines catalyzed by chiral cationic Ru-diamine complex(R,R)-1a was developed,affording chiral piperazine derivatives with good enantioselectivities(up to 89% ee).
基金the NSFC(No.20272037)the NSF of Sichuan(No.07ZA109)the foundation of Xihua University(No. R0723315) and(No.XZD0912-09) for the financial support of this work
文摘Chiral N,N＇-dialkylated cyclohexanediamine derived ligands have been synthesized and used in the asymmetric hydrogenation of aryl ketones.Optically active alcohols with up to 90%enantiomeric excess were obtained in high yields.
基金This work was supported by the National Natural Science Foundation of China （No. 21372169） and Sichuan Provincial Foundation （2008SG0021）. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We would like to thank the Analytical ＆ Testing Center of Sichuan University for CCD X-ray single crystal diffractometer work and circular dichroism CD spectrometer work. We are grateful to Daibing Luo and Yani Xie for help with the single crystal and circular dichroism measurements.
文摘The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.
