- Transition metal-diene complexes in organic synthesis, Part 22. The iron-mediated quinone imine cyclization: A general route to 3-hydroxycarbazoles
-
Electrophilic aromatic substitution of 4-methoxyarylamines 2 by the tricarbonyliron-complexed cyclohexadienylium cations 1 leading to the iron complexes 3 is described. Chemoselective oxidation of the arylamine moiety of the complexes 3 to the quinone imine and iron-mediated quinone imine cyclization using appropriate oxidizing reagents (activated manganese dioxide or thallium(III) trifluoroacetate) led to the tricarbonyliron-complexed 4b,8a-dihydrocarbazol-3-ones 5. Demetalation of 5 with trimethylamine N-oxide at room temperature occurred with concomitant aromatization of the organic ligand and provided a broad access to the 3-hydroxy-9H-carbazoles 7.
- Knolker,Bauermeister,Pannek,Wolpert
-
-
Read Online
- Palladium supported on metal–organic framework as a catalyst for the hydrogenation of nitroarenes under mild conditions
-
Sustainable development demands an environmentally friendly and efficient method for the hydrogenation of organic molecules, including the hydrogenation of functionalized nitroarenes. In this study, a highly active and selective metal–organic framework-supported palladium catalyst was prepared for the catalytic hydrogenation of nitroarenes. High selectivity (>99%) and excellent yield (98%) of aniline were realized after 2 hours in ethanol under hydrogen (1 atm) at room temperature. The reductions were successfully carried out in the presence of a wide range of other reducible functional groups. More importantly, the catalyst was very stable without the loss of its catalytic activity after five cycles.
- Bao, Lingxiang,Fei, Teng,Li, Jiazhe,Pang, Siping,Sun, Chenghui,Yan, Zhiyuan,Yu, Zongbao
-
-
- C-H Amination of Arenes with Hydroxylamine
-
This Letter describes the development of a TiIII-mediated reaction for the C-H amination of arenes with hydroxylamine. This reaction is applied to a variety of electron-rich (hetero)arene substrates, including a series of natural products and pharmaceuticals. It offers the advantages of mild conditions (room temperature), fast reaction rates (30 min), compatibility with ambient moisture and air, scalability, and the use of inexpensive commercial reagents.
- See, Yi Yang,Sanford, Melanie S.
-
supporting information
p. 2931 - 2934
(2020/04/09)
-
- Enantioselective Synthesis of (+)-Mitomycin K by a Palladium-Catalyzed Oxidative Tandem Cyclization
-
The mitomycins, a family of bioactive natural products, feature a compact 6/5/5-fused polycyclic ring structure densely decorated with highly reactive and/or fragile quinone, amino ketal, and aziridine as well as carbamate moieties. It is this striking feature that has defeated numerous synthetic attempts towards these apparently small molecules, rendering them one of the most formidable targets for total synthesis. We herein report the first enantioselective synthesis of (+)-mitomycin K, a representative of G series mitomycins. The key step of this synthesis is an enantioselective oxidative cyclization catalyzed by a palladium/(+)-sparteine system that had previously been developed by our group. The robustness of this method bodes well for further applications in the asymmetric total synthesis of natural products, particularly those with characteristic 6/5/5-fused pyrroloindole skeletons.
- Gu, Qiang-Shuai,Yang, Dan
-
supporting information
p. 5886 - 5889
(2017/05/12)
-
- Fe-Catalyzed Amination of (Hetero)Arenes with a Redox-Active Aminating Reagent under Mild Conditions
-
A novel and efficient Fe-catalyzed direct C?H amination (NH2) of arenes is reported using a new redox-active aminating reagent. The reaction is simple, and can be performed under air, mild, and redox-neutral conditions. This protocol has a broad substrate scope and could be used in the late-stage modification of bioactive compounds. Mechanistic studies demonstrate that a radical pathway could be involved in this transformation.
- Liu, Jianzhong,Wu, Kai,Shen, Tao,Liang, Yujie,Zou, Miancheng,Zhu, Yuchao,Li, Xinwei,Li, Xinyao,Jiao, Ning
-
supporting information
p. 563 - 567
(2017/01/18)
-
- Direct synthesis of anilines and nitrosobenzenes from phenols
-
A one-pot synthesis of anilines and nitrosobenzenes from phenols has been developed using an ipso-oxidative aromatic substitution (iSOAr) process. The products are obtained in good yields under mild and metal-free conditions. The leaving group effect on reactions that proceed through mixed quionone monoketals has also been investigated and a predictive model has been established.
- St Amant,Frazier,Newmeyer,Fruehauf,Read De Alaniz
-
p. 5520 - 5524
(2016/07/06)
-
- Direct metal-free synthesis of diarylamines from 2-nitropropane via the twofold C-H functionalization of arenes
-
Synthesis of symmetric diarylamines via a twofold intermolecular electrophilic C-H functionalization of electron-rich arenes by umpolung-activated nitroalkane in polyphosphoric acid is demonstrated.
- Aksenov, Alexander V.,Aksenov, Nicolai A.,Orazova, Naila A.,Aksenov, Dmitrii A.,Dmitriev, Maksim V.,Rubin, Michael
-
p. 84849 - 84855
(2015/10/28)
-
- 2- (TERT - BUTOXY) -2- (7 -METHYLQUINOLIN- 6 - YL) ACETIC ACID DERIVATIVES FOR TREATING AIDS
-
The invention provides compounds and salts thereof as d herein. The invention also provides pharmaceutical compositions comprising a compound disclosed herein, processes for preparing compounds disclosed herein, intermediates useful for preparing compound
- -
-
Page/Page column 75; 76
(2013/07/19)
-
- Electrochemical C-H amination: Synthesis of aromatic primary amines via N -arylpyridinium ions
-
We have developed a new method for C-H amination of aromatic compounds based on electrochemical oxidation of aromatic compounds in the presence of pyridine followed by the reaction of the resulting N-arylpyridinium ions with an alkylamine. This new transformation serves as a powerful method for synthesizing aromatic primary amines from aromatic compounds without using metal catalysts and harsh chemical reagents. High chemoselectivity of the present method is demonstrated by C-H amination of aromatic compounds bearing a nitro group to give a key intermediate for the synthesis of VLA-4 antagonist.
- Morofuji, Tatsuya,Shimizu, Akihiro,Yoshida, Jun-Ichi
-
supporting information
p. 5000 - 5003
(2013/05/22)
-
- 2 -QUINOLINYL- ACETIC ACID DERIVATIVES AS HIV ANTIVIRAL COMPOUNDS
-
The invention provides compounds of formula (I): or a salt thereof as described herein. The invention also provides pharmaceutical compositions comprising a compound of formula (I), processes for preparing compounds of formula (I), intermediates useful fo
- -
-
Page/Page column 163
(2012/01/15)
-
- BENZOTRIAZEPINONE DERIVATIVES
-
The present invention is concerned with benzotriazepinone derivatives, their intermediates, uses thereof and processes for their production. In particular, the present invention relates to parathyroid hormone (PTH) and parathyroid hormone related protein (PTHrp) receptor ligands, (PTH-I or PTH/PTHrp receptor ligands). The invention also relates to methods of preparing such ligands and to compounds which are useful as intermediates in such methods.
- -
-
Page/Page column 63
(2010/11/29)
-
- 2- (4-0X0-4H-QUINAZ0LIN-3-YL) ACETAMIDES AND THEIR USE AS VASOPRESSIN V3 ANTAGONISTS
-
The present invention relates to 2-(4-oxo4H-quinazolin-3-yl)acetamicle derivatives of formula (I), and to their use as vasopressin V3 antagonists, particularly for the treatment of depression.
- -
-
Page/Page column 33
(2010/11/23)
-
- 1,2-disubstituted 1,4-dihydro-4-oxoquinoline compounds
-
The present invention relates to substituted 1,4-dihydro-4-oxoquinolines having antiviral activity. The substituents are present at positions 1, 2 and at least one of 5-8 positions of the quinoline ring.
- -
-
-
- Amination of arenes with N,N-dimethyl-2-imidazolidinone O-methoxyacetyloxime
-
Treatment of nucleophilic arenes with N,N-dimethyl-2imidazolidinone O-methoxyacetyloxime and SnCl4 produced the corresponding N-arylimines, which were converted to anilines by hydrolysis with CsOH and to N-methylanilines by LiAlH4 reduction.
- Baldovini, Nicolas,Kitamura, Mitsuru,Narasaka, Koichi
-
p. 548 - 549
(2007/10/03)
-
