Development of Highly Selective Asymmetric Reaction Systems Utilizing Transition Metal Complexes

1.脱氢寡肽的不对称氢化反应：对于Y-Phe-(S或R)-AA-OH的不对称氢化反应，合成了一种新型的含氨基的非手性双膦配体DPP-AE，Rh-DPP-AE催化剂具有较高的立体选择性(84.96%D.E.)与预期DPP-AE与底物之间的静电相互作用的氨基保护基团(Ac或Z)无关。通过详细的研究，得出结论：配体与底物之间的静电相互作用使络合物能够进行多点识别，从而产生高效的1，4-不对称诱导。选择性强烈依赖于溶剂的极性，在所考察的醇类中，甲醇的选择性最好。在DPP-AE中引入给电子基(o-Me和p-Me)，提高了底物专一性。在这些Rh-DPP-AE体系中观察到选择性对温度的特定依赖关系。2.环烯丙基化合物的不对称烷基化反应：Pd-手性二亚膦(POP)体系为…环烯丙基化合物的对映体选择性烷基化反应比双膦体系更有效。对POP进行了修饰，以改变配体的电子和空间因子。在POP的苯基的m位引入甲氧基或两个膦氧基的不对称可以有效地提高对映体的选择性。反应还依赖于烯酸阴离子和50%e.e的结构。在甲醇中用乙酰氨基丙二酸二甲酯阴离子反应得到。3.亚胺类化合物的不对称亲核加成反应：考察了Co(III)-氨基酸络合物向手性Co(III)-亚氨酸络合物的转化，并根据氨基酸络合物的结构建立了相应的脱氢和消除条件。测定了钴-亚胺酸络合物的晶体结构。该配合物采用平面亚胺酸络合物的&lt；Lambda&gt；_2构型。亚胺酸络合物被NaBH4还原得到光学活性的氨基酸络合物，产率很高。较少

1. Asymmetric hydrogenation of dehydrooligopeptides: For the asymmetric hydrogenation of Y- phe-(S or R)-AA-OH, novel achiral diphosphine DPP-AE having amino moiety was developed, and Rh - DPP-AE catalyst afforded high stereoselectivities(84 96%d.e.) irrespective of the amino protecting groups(Ac or Z) where electrostatic interaction between DPP-AE and substrate was expected. By detailed studies, it was concluded that the electrostatic interaction between ligand and substrate enabled a multi-points recognition by the complex to cause highly efficient 1,4-asymmetric induction. The selectivity was strongly dependent on the solvent polarity and methanol afforded best results among alcohols examined. Introduction of electron-donating group(o-me and p-Me) to DPP-AE enhanced the substrate-specificity. Specific dependency of the selectivity on the temperature was observed in these Rh-DPP-AE systems. 2. Asymmetric alkylation of cyclic allylic compounds: Pd-chiral diphosphinite(POP) systems wer … More e proved to be more effective for the enantiotopos-selective alkylation of cyclic allylic compounds than diphosphine systems. POP was modified in order to alter the electronic and steric factors of the ligand. Introducton of methoxly group to the m-position of the phenyl substituent of POP or unsymmetrization of the two phosphinoxy groups was effective to raise the enantio-selectivity. The reaction was also dependent on the structure of the enolate anion and 50%e.e. was obtained in the reaction using dimethyl acetylaminomalonate anion in methanol. 3. Asymmetric nucleophilic addition to imine compounds: The conversion of Co(III)- amino acidato complex to xhiral Co(III)-imino acidato complex was examined, and the conditions of dehydrogenation and <beta>-elimination were established corresponding to the structure of the amino acidato complexes. The crystal structure of thr Co-imino acidata complex was determined. The complex adopted a <LAMBDA>_2 configuration with a planar imino acidato chelate. Reduction of the imino acidato complex by NaBH4 addorded an optically active amino acidato complex in a high yield. Less