新型手性N-Oxide金属化合物的合成与催化研究

项目名称： 新型手性N-Oxide金属化合物的合成与催化研究

项目编号： No.20872062

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 化学工业

项目作者： 宋海斌

作者单位： 南开大学

项目金额： 25万元

中文摘要： 合成新型手性N-Oxide化合物，其和不同金属反应得到金属络合物。通过N-Oxide与氮杂卡宾环对金属离子的配位能力的不同，螯和环的大小不同，及配体手性骨架的不同来使不对称催化剂有不同结构及反应性能。测定这些金属有机化合物的结构及对其催化性能进行研究，研究影响催化性能的各种因素，找出具有较好性能的化合物，为找出一种高效新型配体提供一种设计方向，也可扩展N-Oxide和氮杂卡宾环在不对称催化反应中的应用。

中文关键词： 手性咪唑盐; 氮氧化合物;氮卡宾金属络合物;催化

英文摘要： In this project the efforts were focused on the N-heterocyclic carbenes which bearing different donor groups containg P or O atoms. Series of new compounds were synthesized and some of them were applied in catalytic reaction with good effect.Starting with chloromethyl pyridine N-oxide, 1-phenyl-3-methylpyridine nitrogen-oxide imidazole Salt NO-L1, 1-mesityl-3-methylpyridine nitrogen-oxide imidazole Salt NO-L2, and chiral binaphthyl benzimidazole salt (R)-1d, (S)-2d were synthesized. The NO-L1 and NO-L2 have been applied to C-C coupling with moderate to good yields. Eight chiral imidazolium salts have been designed and successfully prepared from chiral 1,1'-binaphthyl-2,2'-diamine and 2,2'-diamino-6,6'-dimethyl-1,1'-biphenyl, and their use as ligand in preparation of NHC-complex has been investigated. The coordination property coupled with the electronic effect of the ligand play an important role in the complex formation. For example, treatment of pyridine derived imidazolium salt 4a with [Rh(COD)Cl]2 and KI in the presence of NaOAc gives the mononuclear ionic Rh(III) complex 5a, while the pyridine-oxide derived imidazolium salt 7a affords a neutral binuclear Rh(I) complex 8a. All the new compounds have been fully chracterized various spectroscopic data and elemental analyses. The solid-state structures of nine compounds have been further confirmed by X-ray diffraction analyses. The chiral NHC-Rh(III) and NHC-Ir(III) complexes are active catalysts for asymmetric allylation reaction of benzaldehyde and asymmetric hydrosilylation reaction of acetophenone, but their enantioselectivities are moderate, the ee value are only up to 48% and 60%, respectively.

英文关键词： Chiral imidazolium salts;N-oxides; NHC-complexes;Catalysis