13021-14-2Relevant articles and documents
Self-Immolative System for Disclosure of Reactive Electrophilic Alkylating Agents: Understanding the Role of the Reporter Group
Chippindale, Ann M.,Gavriel, Alexander G.,Hayes, Wayne,Khurana, Gurjeet S.,Leroux, Flavien,Lewis, Viliyana G.,Russell, Andrew T.,Sambrook, Mark R.
, p. 10263 - 10279 (2021/08/16)
The development of stable, efficient chemoselective self-immolative systems, for use in applications such as sensors, requires the optimization of the reactivity and degradation characteristics of the self-immolative unit. In this paper, we describe the effect that the structure of the reporter group has upon the self-immolative efficacy of a prototype system designed for the disclosure of electrophilic alkylating agents. The amine of the reporter group (a nitroaniline unit) was a constituent part of a carbamate that functioned as the self-immolative unit. The number and position of substituents on the nitroaniline unit were found to play a key role in the rate of self-immolative degradation and release of the reporter group. The position of the nitro substituent (meta- vs para-) and the methyl groups in the ortho-position relative to the carbamate exhibited an influence on the rate of elimination and stability of the self-immolative system. The ortho-methyl substituents imparted a twist on the N-C (aromatic) bond leading to increased resonance of the amine nitrogen's lone pair into the carbonyl moiety and a decrease of the leaving character of the carbamate group; concomitantly, this may also make it a less electron-withdrawing group and lead to less acidification of the eliminated β-hydrogen.
Synthesis of N-Alkyl Anilines from Arenes via Iron-Promoted Aromatic C-H Amination
Falk, Eric,Gasser, Valentina C. M.,Morandi, Bill
supporting information, p. 1422 - 1426 (2021/03/08)
We report both an intermolecular C-H amination of arenes to access N-methylanilines and an intramolecular variant for the synthesis of tetrahydroquinolines. A newly developed, highly electrophilic aminating reagent was key for the direct synthesis of unprotected N-methylanilines from simple arenes. The reactions display a broad functional group tolerance and employ catalytic amounts of a benign iron salt under mild reaction conditions.
A Metal-Free Direct Arene C?H Amination
Wang, Tao,Hoffmann, Marvin,Dreuw, Andreas,Hasagi?, Edina,Hu, Chao,Stein, Philipp M.,Witzel, Sina,Shi, Hongwei,Yang, Yangyang,Rudolph, Matthias,Stuck, Fabian,Rominger, Frank,Kerscher, Marion,Comba, Peter,Hashmi, A. Stephen K.
supporting information, p. 2783 - 2795 (2021/04/05)
The synthesis of aryl amines via the formation of a C?N bond is an essential tool for the preparation of functional materials, active pharmaceutical ingredients and bioactive products. Usually, this chemical connection is only possible by transition metal-catalyzed reactions, photochemistry or electrochemistry. Here, we report a metal-free arene C?H amination using hydroxylamine derivatives under benign conditions. A charge transfer interaction between the aminating reagents TsONHR and the arene substrates enables the chemoselective amination of the arene, even in the presence of various functional groups. Oxygen was crucial for an effective conversion and its accelerating role for the electron transfer step was proven experimentally. In addition, this was rationalized by a theoretical study which indicated the involvement of a dioxygen-bridged complex with a “Sandwich-like” arrangement of the aromatic starting materials and the aminating agents at the dioxygen molecule. (Figure presented.).
SELF-IMMOLATIVE SYSTEMS
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Page/Page column 22; 23, (2020/05/28)
The present invention is concerned with self-immolative recognition and/or responsive systems for electrophilic compounds, especially alkylating agents, which systems may comprise disclosure or detection of the alkylating agent. The present invention is especially concerned with non-protic triggered self-immolative systems, molecules, and methods, and in particular for detection of non- protic electrophilic agents, and especially alkylating agents, for example alkyl or benzylic halides, which may be found in pesticides or fumigants, or chemical warfare agents.
Cu(II)-Mediated N-H and N-Alkyl Aryl Amination and Olefin Aziridination
Munnuri, Sailu,Anugu, Raghunath Reddy,Falck, John R.
supporting information, p. 1926 - 1929 (2019/03/11)
Cu(II)-mediated direct NH2 and NH alkyl aryl aminations and olefin aziridinations are described. These room-temperature, one-pot, environmentally friendly procedures replace costly Rh2 catalysts and, in some instances, display important differences with comparable Rh2- and Fe-supported reactions.
DIRECT C-H AMINATION AND AZA-ANNULATION
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Paragraph 0132; 0138; 0139; 0140, (2019/06/07)
In some aspects, the present disclosure provides methods of aminating an aromatic compound comprising reacting an aminating agent with an aromatic compound in the presence of a rhodium catalyst. In some embodiments, the methods may comprise aminating an aromatic compound which contains multiple different functional groups. The methods described herein may also be used to create bicyclic system comprising reacting an intramolecular aminating agent with an aromatic ring to obtain a second ring containing a nitrogen atom. In another aspect, the methods described herein may also be used to create a cyclic aliphatic cyclic/poly cyclic amine system comprising a reacting an intramolecular aminating agent by insertion into a C(sp3)-H bond.
N-Monomethylation of Aromatic Amines with Methanol via PNHP-Pincer Ru Catalysts
Ogata, Osamu,Nara, Hideki,Fujiwhara, Mitsuhiko,Matsumura, Kazuhiko,Kayaki, Yoshihito
supporting information, p. 3866 - 3870 (2018/07/25)
The use of methanol for the selective methylation of aromatic amines with RuHCl(CO)(PNHP) (PNHP = bis(2-diphenylphosphinoethyl)amine) is reported. Various aromatic amines were transformed into their corresponding monomethylated secondary amines in high yields at 150 °C with a very low catalyst loading (0.02-0.1 mol %) in the presence of KOtBu (20-60 mol %). The catalyst precursor, RuHCl(CO)(PNHP), was converted to [RuH(CO)2(PNHP)]+ under the catalytic conditions and also serves as a highly effective catalyst. The robustness of this catalyst contributes to its outstanding catalytic activity, even under reaction conditions, in which CO is liberated from methanol.
Dirhodium-catalyzed C-H arene amination using hydroxylamines
Paudyal, Mahesh P.,Adebesin, Adeniyi Michael,Burt, Scott R.,Ess, Daniel H.,Ma, Zhiwei,Kürti, László,Falck, John R.
, p. 1144 - 1147 (2016/11/09)
Primary and N-alkyl arylamine motifs are key functional groups in pharmaceuticals, agrochemicals, and functional materials, as well as in bioactive natural products. However, there is a dearth of generally applicablemethods for the direct replacement of aryl hydrogens with NH2/NH(alkyl) moieties. Here, we present a mild dirhodium-catalyzed C-H amination for conversion of structurally diverse monocyclic and fused aromatics to the corresponding primary and N-alkyl arylamines using NH2/NH(alkyl)-O-(sulfonyl)hydroxylamines as aminating agents; the relatively weak RSO2O-N bond functions as an internal oxidant. The methodology is operationally simple, scalable, and fast at or below ambient temperature, furnishing arylamines in moderate-to-good yields and with good regioselectivity. It can be readily extended to the synthesis of fused N-heterocycles.
Redox inactive metal ion triggered N-dealkylation by an iron catalyst with dioxygen activation: A lesson from lipoxygenases
Zhang, Jisheng,Wang, Yujuan,Luo, Nengchao,Chen, Zhuqi,Wu, Kangbing,Yin, Guochuan
, p. 9847 - 9859 (2015/06/08)
Utilization of dioxygen as the terminal oxidant at ambient temperature is always a challenge in redox chemistry, because it is hard to oxidize a stable redox metal ion like iron(iii) to its high oxidation state to initialize the catalytic cycle. Inspired by the dioxygenation and co-oxidase activity of lipoxygenases, herein, we introduce an alternative protocol to activate the sluggish iron(iii) species with non-redox metal ions, which can promote its oxidizing power to facilitate substrate oxidation with dioxygen, thus initializing the catalytic cycle. In oxidations of N,N-dimethylaniline and its analogues, adding Zn(OTf)2 to the [Fe(TPA)Cl2]Cl catalyst can trigger the amine oxidation with dioxygen, whereas [Fe(TPA)Cl2]Cl alone is very sluggish. In stoichiometric oxidations, it has also been confirmed that the presence of Zn(OTf)2 can apparently improve the electron transfer capability of the [Fe(TPA)Cl2]Cl complex. Experiments using different types of substrates as trapping reagents disclosed that the iron(iv) species does not occur in the catalytic cycle, suggesting that oxidation of amines is initialized by electron transfer rather than hydrogen abstraction. Combined experiments from UV-Vis, high resolution mass spectrometry, electrochemistry, EPR and oxidation kinetics support that the improved electron transfer ability of iron(iii) species originates from its interaction with added Lewis acids like Zn2+ through a plausible chloride or OTf- bridge, which has promoted the redox potential of iron(iii) species. The amine oxidation mechanism was also discussed based on the available data, which resembles the co-oxidase activity of lipoxygenases in oxidative dealkylation of xenobiotic metabolisms where an external electron donor is not essential for dioxygen activation.
HETEROCYCLIC DERIVATIVE HAVING INHIBITORY ACTIVITY ON TYPE-I 11 -HYDROXYSTEROID DEHYDROGENASE
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Page/Page column 137, (2010/08/07)
Disclosed is a compound which is useful as an 11β-hydroxysteroid dehydrogenase type 1 inhibitor. A compound represented by the formula: its pharmaceutically acceptable salt, or a solvate thereof, wherein X is O or S, a broken line and a wavy line represent the presence or the absence of a bond, (i) when a broken line represents the presence of a bond, a wavy line represents the absence of a bond, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, (ii) when a broken line represents the absence of a bond, a wavy line represents the presence of a bond, R1 and R4 are each independently hydrogen, halogen or the like, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, and R5 and R6 are each independently hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like.
