Stereoselective Photoreactions With New Coppe (1) Complexes Possessing A Chiral Conjugate Ligand

合成了一种新的含R(+)-α-甲基苯乙胺的手性2，2‘-联吡啶配体5，5’-二(-)-methylbenzylamido-4，4‘-6，6’-tetramethyl-2，2‘-bipyridine(-)-Tmdcbpy及其铜(I)配合物[Cu(-)-Tmdcbpy)(PPh_3)_2]1，[Cu(-)-Tmdcbpy)(P(C_6H_4-SO_3-m)Ph_2)_2，[Cu((-)-tmdcbpy)((+)-diop)]^+3和[Cu((-)-tmdcbpy)((-)-diop)]^+4.利用这些铜(I)配合物，在与其MLCT吸收带对应的近紫外光照射下，成功地实现了[Cu(EDTA)]^-的立体选择性光还原.最佳立体选择性为44%e.e。当1在乙醇-水(75：25v/v)中使用时。另一方面，立体选择性下降到约17%e.e。当使用2时。[Co(EDTA)]-的猝灭实验清楚地表明，1的反应是通过动态和静态猝灭机制进行的，而2的反应只是通过静态猝灭机制进行的。这些有趣的Diff…1和2之间的更多关系可以用静电相互作用来解释：由于1是正电荷，1很容易与带负电荷的[Co(EDTA)]^-形成加合物，并且由于静电吸引，[Cu^&lt；11&gt；((-)-tmdcbpy)(PPh_3)_2]^&lt；2+&gt；与[Co^&lt；11&gt；(EDTA)]^&lt；2-&gt；的相互作用很强。另一方面，负电荷2在基态不能形成稳定的加合物，[Cu^&lt；11&gt；((-)-tmdcbpy)(P(C6H4SO3-m)Ph)2]^0与[Co(EDTA)]^&lt；2-&gt；然后，以Co(OAc)_2和H_4edta或Na_4edta为原料，在近紫外光的照射下，利用这些铜(I)与氧气的络合物成功地进行了光不对称合成[Co(EDTA)]~-，在该光合反应中，H_4edta的作用下过量生成了Delta-[Co(EDTA)]~-。该反应只能在DMSO中进行，选择性明显取决于EDTA源的种类，钴盐的反阴离子。较少

We synthesized a new chiral 2,2'-bipyridine ligand possessing R (+) -alpha-methylbenzyeamine, 5,5'-di (-) -methylbenzylamido-4,4'-6,6'-tetramethyl-2,2'-bipyridine (-) -tmdcbpy, and its Cu (I) complexes, [Cu ( (-) -tmdcbpy) (PPh_3) _2] 1, [Cu ( (-) -tmdcbpy) (P (C_6H_4-SO_3-m) Ph_2) _2] ^-2, [Cu ( (-) -tmdcbpy) ( (+) -diop) ] ^+3, and [Cu ( (-) -tmdcbpy) ( (-) -diop) ] ^+ 4. Using these Cu (I) complexes, stereoselective photoreduction of [Cu (edta) ] ^-was successfully carried out upon irradiation of near UV light corresponding to the MLCT absorption band of these Cu (I) complexes. The best stereoselectivity was 44%e.e. when 1 was used in ethanol-water (75 : 25 v/v). On the other hand, the stereoselectivity decreases to about 17%e.e. when 2 was used. The quenching experiments with [Co (edta) ] ^-indicated clearly that the reaction of 1 proceeds through dynamic and static quenching mechanism but the reaction of 2 takes place only through static quenching mechanism. These interesting diff … More erences between 1 and 2 are interpreted in terms of the electrostatic interaction : because 1 is positively charged, 1 can easily form an adduct with negatively charged [Co (edta) ] ^-and the interaction of [Cu^<11> ( (-) -tmdcbpy) (PPh_3) _2] ^<2+> with [Co^<11> (edta) ] ^<2->is strong due to the electrostatic attraction. On the other hand, the negatively charge 2 can not form a stable adduct in the ground state, and also the interaction of [Cu^<11> ( (-) -tmdcbpy) (P (C_6H_4SO_3-m) Ph) _2] ^0with [Co (edta) ] ^<2->is weak because of the lack of electrostatic attraction.Then, photo-asymmetric synthesis of [Co (edta) ] ^-was successfully carried out from Co (OAc) _2and H_4edta or Na_4edta, using these Cu (I) complexes with oxygen gas under upon irradiation of near UV light., In this photosynthetic reaction, DELTA- [Co (edta) ] ^-was produced in the excess when H_4edta was used. This reaction was possible only in DMSO,and the selectivity significantly depends on the kind of edta source, counter anion of Co salt. Less