Electronic Tuning of Iron-Oxo-Mediated CH Activation: Effect of Electron-Donating Ligand on Selectivity
作者:Yutaka Hitomi、Kengo Arakawa、Masahito Kodera
DOI:10.1002/chem.201302111
日期:2013.10.18
We have reported previously that an iron(III) complex supported by an anionic pentadentate monoamido ligand, dpaqH (dpaqH=2‐[bis(pyridin‐2‐ylmethyl)]amino‐N‐quinolin‐8‐yl‐acetamido), promotes selective CH hydroxylation with H2O2 with high regioselectivity. Herein, we report on the preparation of FeIII–dpaq derivatives that have a series of substituent groups at the 5‐position of a quinoline moiety
我们之前曾报道过,铁(III)络合物由阴离子五齿单氨基配体dpaq H(dpaq H = 2- [双(吡啶-2-基甲基))氨基-N-喹啉-8-基乙酰氨基)支撑,促进具有高区域选择性的H 2 O 2的选择性CH羟基化。在本文中,我们报道了在母体配体dpaq H(dpaq R,R:OMe,H,Cl和NO 2中,在喹啉部分的5位具有一系列取代基的Fe III -dpaq衍生物的制备方法),并检查它们在CH与H 2羟基化反应中的催化活性O 2。随着取代基的吸电子性提高,选择性和周转数均增加,但环氧化的选择性却呈现相反的趋势。
Electronic tuning of nitric oxide release from manganese nitrosyl complexes by visible light irradiation: enhancement of nitric oxide release efficiency by the nitro-substituted quinoline ligand
作者:Yutaka Hitomi、Yuji Iwamoto、Masahito Kodera
DOI:10.1039/c3dt51719e
日期:——
Manganese nitrosyl MnNO}6 complexes of general formula [Mn(dpaqR)(NO)]ClO4 (1R), where dpaqR denotes a series of pentadentate monoamido ligands, 2-[N,N-bis(pyridin-2-ylmethyl)]-amino-N′-quinolin-8-yl-acetamido with R = OMe, H, Cl and NO2 at the 5-position of the quinoline moiety, were prepared. The derivatives 1R were characterized by 1H NMR, IR and UV–vis spectrometry as well as by single-crystal X-ray crystallography. The N–O bond and the amido CO bond stretching frequencies, as well as the redox potentials of 1R derivatives, substantially varied depending on the nature of the substituent group R on the quinoline ring, indicating that the π back-bonding from Mn to NO groups becomes weak as the substituent group R becomes more electron withdrawing. The nitro-substituted derivative 1NO2 is unique among the series; the tail of its absorption bands extends to the NIR region (up to 700 nm), and the apparent NO releasing rate from 1NO2 by light irradiation at 650 nm was ca. 4-fold higher than the other derivatives.
制备了通式为[Mn(dpaqR)(NO)]ClO4 (1R)的亚硝基锰MnNO}6配合物,其中 dpaqR 表示一系列五价单氨基配体,2-[N,N-双(吡啶-2-基甲基)]-氨基-N′-喹啉-8-基乙酰氨基,喹啉分子 5 位上的 R = OMe、H、Cl 和 NO2。衍生物 1R 通过 1H-核磁共振、红外光谱、紫外-可见光谱以及单晶 X 射线晶体学进行了表征。1R 衍生物的 N-O 键和氨基 CO 键伸展频率以及氧化还原电位随喹啉环上取代基 R 的性质不同而有很大的变化,这表明随着取代基 R 的电子撤回性增强,Mn 与 NO 基团之间的 π 反键作用会变弱。硝基取代衍生物 1NO2 在这一系列衍生物中是独一无二的;其吸收带的尾部延伸到了近红外区域(高达 700 纳米),在 650 纳米波长的光照射下,1NO2 的表观 NO 释放率比其他衍生物高出约 4 倍。
Mononuclear nonheme iron(<scp>iii</scp>) complexes that show superoxide dismutase-like activity and antioxidant effects against menadione-mediated oxidative stress