کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
68124 48503 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthesis and characterization of a novel type of self-assembled chiral zirconium phosphonates and its application for heterogeneous asymmetric catalysis
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Synthesis and characterization of a novel type of self-assembled chiral zirconium phosphonates and its application for heterogeneous asymmetric catalysis
چکیده انگلیسی

A readily available (1S,2R)-(+)-2-amino-1,2-diphenylethanol and (1R,2S)-(−)-2-amino-1,2-diphenylethanol were immobilized on the layered zirconium phosphonates and the hybrid chiral zirconium phosphonates framework had been synthesized for the first time. The solid catalysts were characterized by IR, AFM, TG, XRD and elemental analysis. AFM showed that the self-assembled structure of chiral organic ligands on the surface of zirconium phosphonates 4 lined up regularly and homogeneously at 1.1 nm distance. XRD data indicated that zirconium phosphonate 4 was semi-crystalline with the interlayer space 20.11 Å. Zirconium phosphonates 4 enantioselectively catalysized the addition of Et2Zn to benzaldehyde to afford optical secondary alcohol in >90% yield and 51% e.e. which only decrease at 6% enantiomeric excess lower than the corresponding chiral ligand (1R,2S)-(−)-2 in homogeneous asymmetric catalysis.

A readily available (1S,2R)-(+)-2-amino-1,2-diphenylethanol and (1R,2S)-(−)-2-amino-1,2-diphenylethanol were immobilized on the layered zirconium phosphonates for the first time to obtain the self-assembled structure on the surface lined regularly and homogeneously at 1.1 nm distance. Zirconium phosphonates (1S,2R)-(+)-4a with the interlayer space 20.11 Å enentioselectively catalysized the addition of Et2Zn to benzaldehyde to afford optical secondary alcohol in >90% yield and 51% e.e. Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Catalysis A: Chemical - Volume 265, Issues 1–2, 16 March 2007, Pages 316–322
نویسندگان
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