- Systematic ligand variation to modulate the electrochemical properties of iron and manganese complexes
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A series of iron(+iii) and manganese(+ii) complexes based on the dpaqR-ligand system (dpaq = 2-[bis(pyridine-2-ylmethyl)]amino-N-quinolin-8-yl-acetamide) were investigated using cyclic voltammetry (CV) to elucidate how the electronic properties of the ligands influence the overpotential and catalytic current in the context of water oxidation catalysis. For the Fe-complexes an electron withdrawing NO2 or CF3 group attached to the 5-position of the quinoline unit increased the catalytic current, but only with a simultaneous increase of the overpotential. However, when a pyrene moiety was attached to the dipicolylamine unit of the ligand, the overpotential decreased with concomitant increase of the catalytic current. Although the manganese complexes showed no reversible formation of a molecular catalytically active species for water oxidation, the variations of the ligand scaffold affected largely the same trends in their electrochemical behavior.
- Rohner, Stefan S.,Kinzel, Niklas W.,Werlé, Christophe,Leitner, Walter
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- Transition metal free oxygenation of 8-aminoquinoline amides in water
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The oxygenation of 8-aminoquinoline amides by benzoyl peroxide at the C5 position in water is developed in the absence of a transition metal catalyst, affording the desired products in moderate to good yields of up to 88%. Mechanism studies reveal that the reaction would involve a radical process.
- Yao, Xinghui,Weng, Xin,Wang, Kaixuan,Xiang, Haifeng,Zhou, Xiangge
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p. 2472 - 2476
(2018/06/11)
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- Auxiliary-Directed C(sp3)?H Arylation by Synergistic Photoredox and Palladium Catalysis
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Herein we describe the auxiliary-directed arylation of unactivated C(sp3)?H bonds with aryldiazonium salts, which proceeds under synergistic photoredox and palladium catalysis. The site-selective arylation of aliphatic amides with α-quaternary centres is achieved with high selectivity for β-methyl C(sp3)?H bonds. This operationally simple method is compatible with carbocyclic amides, a range of aryldiazonium salts and proceeds at ambient conditions.
- Czyz, Milena L.,Lupton, David W.,Polyzos, Anastasios
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p. 14450 - 14453
(2017/10/07)
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- A First Example of Cobalt-Catalyzed Remote C H Functionalization of 8-Aminoquinolines Operating through a Single Electron Transfer Mechanism
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The development of new C H functionalization protocols based on inexpensive cobalt catalysts is currently attracting significant interest. Functionalized 8-aminoquinoline compounds are high-potential building blocks in organic chemistry and pharmaceutical compounds and new facile routes for their preparation would be highly valuable. Recently, copper has been applied as catalyst for the functionalization of 8-aminoquinoline compounds and found to operate through a single electron transfer (SET) mechanism, although requiring elevated reaction temperatures. Herein, we described the first example of a cobalt-catalyzed remote C H functionalization of 8-aminoquinoline compounds operating through a SET mechanism, exemplified using a practical and mild nitration protocol. The reaction uses inexpensive cobalt nitrate hexahydrate [Co(NO3)2?6 H2O] as catalyst and tert-butyl nitrite (TBN) as nitro source. This methodology offers the basis for the facile preparation of many new functionalized 8-aminoquinoline derivatives. (Figure presented.).
- Whiteoak, Christopher J.,Planas, Oriol,Company, Anna,Ribas, Xavi
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supporting information
p. 1679 - 1688
(2016/10/13)
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- Auxiliary-assisted palladium-catalyzed halogenation of unactivated C(sp3)-H bonds at room temperature
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The direct transformation of unactivated C(sp3)-H bonds into C-halogen bonds was achieved by palladium catalysis at room temperature with good functional group tolerance. Some drugs and natural products were readily modified by this method. Merged with substitution reaction, newly formed C-X bonds can be transformed into diverse C-O, C-S, C-C and C-N bonds. A preliminary mechanism study demonstrates that solvent is crucial for C-H activation and the C-H activation step is involved in the rate-limiting step. An isolated Pd(ii) intermediate can be transformed into a halogenated product with the retention of conformation which suggests that concerted reductive elimination from Pd(iv) to form a C-X bond was favored.
- Yang, Xinglin,Sun, Yonghui,Sun, Tian-Yu,Rao, Yu
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supporting information
p. 6423 - 6426
(2016/05/24)
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- Heterocyclic compound, the oxidation catalyst and its use
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Provided are: a heterocyclic compound which provides an oxidation catalyst having high selectivity; a metal complex catalyst which uses the heterocyclic compound; a use of the metal complex catalyst; and a method for producing an alcohol. A heterocyclic compound of the present invention is characterized by being represented by general formula (1). (In the formula, R1 represents a nitro group, a halogen atom, a trifluoromethyl group or a C1-C6 alkoxycarbonyl group; each of R2 and R6 independently represents a hydrogen atom or a C1-C6 alkyl group; each of R3 and R7 independently represents a hydrogen atom, a nitro group, a halogen atom, a C1-C6 alkoxy group or a C1-C6 dialkylamino group; each of R4 and R8 independently represents a hydrogen atom, a C1-C6 alkyl group or a C1-C6 alkoxycarbonyl group; and each of R5 and R9 independently represents a hydrogen atom or a C1-C6 alkyl group.)
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- Regio- and stereospecific synthesis of C-3 functionalized proline derivatives by palladium catalyzed directed C(sp3)-H Arylation
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Functionalization of C(sp3)-H bonds at the unactivated 3-position of proline derivatives has been achieved using aryl iodides and palladium catalysis. This directly affords cis-2,3-disubstituted pyrrolidines as single stereoisomers. 3-Arylation
- Affron, Dominic P.,Davis, Owen A.,Bull, James A.
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p. 4956 - 4959
(2015/04/27)
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- Electronic tuning of iron-oxo-mediated C-H activation: Effect of electron-donating ligand on selectivity
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We have reported previously that an iron(III) complex supported by an anionic pentadentate monoamido ligand, dpaqH (dpaq H=2-[bis(pyridin-2-ylmethyl)]amino-N-quinolin-8-yl-acetamido), promotes selective C-H 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 in the parent ligand dpaqH (dpaqR, R: OMe, H, Cl, and NO2), and examine them with respect to their catalytic activity in C-H hydroxylation with H2O2. As the substituent group becomes more electron-withdrawing, both the selectivity and the turnover number increase, but the selectivity of epoxidation shows the opposite trend. Copyright
- Hitomi, Yutaka,Arakawa, Kengo,Kodera, Masahito
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supporting information
p. 14697 - 14701
(2013/11/06)
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- Novel Sulfonaminoquinoline Hepcidin Antagonists
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The present invention relates to novel hepcidin antagonists, pharmaceutical compositions comprising them and the use thereof as medicaments for the use in the treatment of iron metabolism disorders, such as, in particular, iron deficiency diseases and anemias, in particular anemias in connection with chronic inflammatory diseases.
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Page/Page column 130
(2012/09/05)
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- TRIPLE SUBSTITUTED PHENANTHROLINE DERIVATIVES FOR THE TREATMENT OF NEURODEGENERATIVE OR HAEMATOLOGICAL DISEASES OR CONDITIONS, OR CANCER
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The present invention relates to a new family of triple substituted phenantroline derivatives of formula (I), which are useful for the treatment or profilaxis of a neurodegenerative or haematological disease or condition or cancer, their use as a medicament, especially for treating a neurodegenerative or haematological disease or condition or cancer, and a pharmaceutical composition comprising the compounds.
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Page/Page column 31-32
(2010/06/22)
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