- One-Pot Tandem ortho-Naphthoquinone-Catalyzed Aerobic Nitrosation of N-Alkylanilines and Rh(III)-Catalyzed C-H Functionalization Sequence to Indole and Aniline Derivatives
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The nitroso group served as a traceless directing group for the C-H functionalization of N-alkylanilines, ultimately removed after functioning either as an internal oxidant or under subsequent reducing conditions. The unique ability of o-NQ catalysts to aerobically oxidize the N-alkylanilines without using solvents and stoichiometric amounts of oxidants has rendered the new opportunity to develop the telescoped catalyst systems without a need for directly handling the hazardous N-nitroso compounds.
- Si, Tengda,Kim, Hun Young,Oh, Kyungsoo
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p. 1152 - 1163
(2021/01/14)
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- Access to Branched Allylarenes via Rhodium(III)-Catalyzed C-H Allylation of (Hetero)arenes with 2-Methylidenetrimethylene Carbonate
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A rhodium(III)-catalyzed C-H allylation of (hetero)arenes by using 2-methylidenetrimethylene carbonate as an efficient allylic source has been developed for the first time. Five different directing groups including oxime, N-nitroso, purine, pyridine, and pyrimidine were compatible, delivering various branched allylarenes bearing an allylic hydroxyl group in moderate to excellent yields.
- Zhang, Shang-Shi,Zheng, Yi-Chuan,Zhang, Zi-Wu,Chen, Shao-Yong,Xie, Hui,Shu, Bing,Song, Jia-Lin,Liu, Yan-Zhi,Zeng, Yao-Fu,Zhang, Luyong
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supporting information
p. 5719 - 5723
(2021/08/16)
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- Three-Component Couplings among Heteroarenes, Difluorocyclopropenes, and Water via C-H Activation
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Three-component couplings have been realized for efficiently constructing various nitrogen-containing skeletons via C-H activation, where difluorocyclopropenes have been first identified as coupling partners. Many substrates including sp2 and sp3 C-H substrates were well tolerated, furnishing the corresponding products in good yields. Furthermore, a catalyst-dependent reaction was also developed, enabling divergent construction of two different frameworks. The application value of these reactions was demonstrated in gram-scale experiments with as little as 1 mol % catalyst.
- Liu, Xuexin,Chen, Jian,Yang, Chunyan,Wu, Zhouping,Li, Zhiyang,Shi, Yuesen,Huang, Tianle,Yang, Zhongzhen,Wu, Yong
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supporting information
p. 6831 - 6835
(2021/09/08)
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- Rhodium-catalyzed tandem acylmethylation/annulation ofN-nitrosoanilines with sulfoxonium ylides for the synthesis of substituted indazoleN-oxides
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An atom-economical protocol for synthesizing indazoleN-oxides from readily availableN-nitrosoanilines and sulfoxonium ylides through the rhodium(iii)-catalyzed C-H activation and cyclization reaction is described here. This protocol employs nitroso as a traceless directing group. The transformation features powerful reactivity, tolerates various functional groups, and proceeds with moderate to good yields under an ambient atmosphere, providing a straightforward approach to access structurally diverse and valuable indazoleN-oxide derivatives. Importantly, this new annulation process represents a hitherto unobserved reactivity pattern for theN-nitroso group.
- Cui, Xin-F,Huang, Guo-Sh
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supporting information
p. 4014 - 4018
(2020/06/09)
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- Rh(iii)-catalyzed, hydrazine-directed C-H functionalization with 1-alkynylcyclobutanols: A new strategy for 1: H -indazoles
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Rh(iii)-catalyzed coupling of phenylhydrazines with 1-alkynylcyclobutanols was realized through a hydrazine-directed C-H functionalization pathway. This [4+1] annulation, based on the cleavage of a Csp-Csp triple bond in alkynylcyclobutanol, provides a new pathway to prepare diverse 1H-indazoles under mild reaction conditions. This journal is
- Zhang, Lei,Chen, Junyu,Chen, Xiahe,Zheng, Xiangyun,Zhou, Jian,Zhong, Tianshuo,Chen, Zhiwei,Yang, Yun-Fang,Jiang, Xinpeng,She, Yuan-Bin,Yu, Chuanming
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supporting information
p. 7415 - 7418
(2020/07/15)
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- Rhodium(iii)-catalyzed indole synthesis at room temperature using the transient oxidizing directing group strategy
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Rh-catalyzed reactions of N-alkyl anilines with internal alkynes at room temperature have been developed using an in situ generated N-nitroso group as a transient oxidizing directing group. Due to mild reaction conditions, this method enabled synthesis of a broad range of N-alkyl indoles, including even two indole-based medicinal compounds. Our work disclosed the feasibility of the transient oxidizing directing group strategy in C-H functionalization reactions, which possesses the potential to enhance overall step-economy and impart new reactivity patterns to substrates.
- Shang, Yaping,Jonnada, Krishna,Yedage, Subhash Laxman,Tu, Hua,Zhang, Xiaofeng,Lou, Xin,Huang, Shijun,Su, Weiping
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supporting information
p. 9547 - 9550
(2019/08/15)
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- Cp?Rh(iii) catalyzed: Ortho -halogenation of N -nitrosoanilines by solvent-controlled regioselective C-H functionalization
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We present a novel, efficient, and regioselective method for the rhodium-catalyzed direct C-H ortho-halogenation of anilines that involves a removable N-nitroso directing group. This method featured mild reaction conditions, wide substrate scope, good functional group tolerance and satisfactory yields. To maintain the high ortho-regioselectivity and conversion, increasing the steric hindrance of the solvent was critical. Preliminary mechanistic studies suggest that C-H activation may be involved in the rate-determining step.
- Peng, Qiujun,Hu, Jian,Huo, Jiyou,Yuan, Hongshun,Xu, Lanting,Pan, Xianhua
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supporting information
p. 4471 - 4481
(2018/06/29)
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- Rhodium-catalyzed oxidative C-H/C-H cross-coupling of aniline with heteroarene: N-nitroso group enabled mild conditions
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The development of transition metal-catalyzed oxidative C-H/C-H cross-coupling between two (hetero)arenes to forge aryl-heteroaryl motifs under mild conditions is an appealing yet challenging task. Herein, we disclose a rhodium-catalyzed oxidative C-H/C-H cross-coupling reaction of an N-nitrosoaniline with a heteroarene under mild conditions. The judicious choice of the N-nitroso group as a directing group enables heightened reactivity. The coupled products could be transformed expediently to (2-aminophenyl)heteroaryl skeletons.
- He, Shuang,Tan, Guangying,Luo, Anping,You, Jingsong
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supporting information
p. 7794 - 7797
(2018/07/25)
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- Highly selective sp3 C-N bond activation of tertiary anilines modulated by steric and thermodynamic factors
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A highly selective sp3 C-N cleavage of tertiary anilines was achieved using the TBN/TEMPO catalyst system. When N,N-diaklylanilines (alkyl, benzyl) were employed, the N-CH3 bond was selectively cleaved via radical C-H activation. Moreover, when the allyl group was installed, totally reverse selectivity was observed. It is worth noting that the solvent effect is also crucial to obtain high reaction efficiency and selectivity.
- Jia, Xiaodong,Li, Pengfei,Shao, Yu,Yuan, Yu,Ji, Honghe,Hou, Wentao,Liu, Xiaofei,Zhang, Xuewen
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supporting information
p. 5568 - 5574
(2017/12/06)
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- Rhodium(III)-Catalyzed Directed C?H Amidation of N-Nitrosoanilines and Subsequent Formation of 1,2-Disubstituted Benzimidazoles
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An efficient rhodium-catalyzed direct C?H amidation of N-nitrosoanilines with 1,4,2-dioxazol-5-ones as amidating agents has been developed. This method featured mild reaction conditions, a wide substrate scope and satisfactory yields. Besides, the amidated products could be readily converted to pharmaceutically valuable 1,2-disubstituted benzimidazoles via an HCl-mediated deprotection/cyclization process in one pot.
- Chen, Yanyu,Zhang, Rong,Peng, Qiujun,Xu, Lanting,Pan, XianHua
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supporting information
p. 2804 - 2808
(2017/10/20)
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- Palladium-catalyzed ortho-acylation of N-Nitrosoanilines with α-oxocarboxylic acids: A convenient method to synthesize N-Nitroso ketones and indazoles
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An efficient and mild protocol for regioselective synthesis of N-Nitroso aryl ketones by palladium-catalyzed direct acylation of arenes using N-Nitroso as directing groups is described. This reaction proceeded smoothly and could tolerate a variety of functional groups. Moreover, this chemistry offers a convenient access to a range of indazoles.
- Zhang, Liang,Wang, Zhe,Guo, Peiyu,Sun, Wei,Li, Ya-Min,Sun, Meng,Hua, Chengwen
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supporting information
p. 2511 - 2514
(2016/05/24)
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- Copper(II)-catalyzed oxidative N-nitrosation of secondary and tertiary amines with nitromethane under an oxygen atmosphere
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The combination of a catalytic amount of Cu(OTf)2 and less than a stoichiometric amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under an O2 atmosphere effectively promoted the N-nitrosation of both secondary aromatic/aliphatic amines and tertiary aromatic amines with nitromethane (CH3NO2) leading to the preparation of N-nitrosamine derivatives.
- Sakai, Norio,Sasaki, Minoru,Ogiwara, Yohei
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supporting information
p. 11638 - 11641
(2015/07/15)
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- Palladium-catalyzed oxidative C-H bond acylation of N-nitrosoanilines with toluene derivatives: A traceless approach to synthesize N-alkyl-2-aminobenzophenones
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A palladium-catalyzed cascade cross-coupling of N-nitroso-anilines and toluene derivatives for the direct synthesis of N-alkyl-2-aminobenzophenones is described. N-nitroso groups in anilines can act as the traceless directing groups while toluene derivatives can serve as effective acyl precursors under mild reaction conditions.
- Wu, Yinuo,Feng, Ling-Jun,Lu, Xiao,Kwong, Fuk Yee,Luo, Hai-Bin
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supporting information
p. 15352 - 15354
(2015/01/08)
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- Rhodium(III)-catalyzed N-nitroso-directed C-H addition to ethyl 2-oxoacetate for cycloaddition/fragmentation synthesis of indazoles
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RhIII-catalyzed N-nitroso-directed C-H addition to ethyl 2-oxoacetate allows subsequent construction of indazoles, a privileged heterocycle scaffold in synthetic chemistry, through the exploitation of reactivity between the directing group and installed group. The formal [2+2] cycloaddition/fragmentation reaction pathway identified herein, a unique reactivity pattern hitherto elusive for the N-nitroso group, emphasizes the importance of forward reactivity analysis in the development of useful C-H functionalization-based synthetic tools. The synthetic utility of the protocol is demonstrated with the synthesis of a tri-cyclic-fused ring system. The diversity of covalent linkages available for the nitroso group should enable the extension of the genre of reactivity reported herein to the synthesis of other types of heterocycles.
- Chen, Jinsen,Chen, Pei,Song, Chao,Zhu, Jin
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supporting information
p. 14245 - 14249
(2015/02/05)
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- Traceless directing strategy: Efficient synthesis of N-alkyl indoles via redox-neutral C-H activation
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A general protocol for the synthesis of N-alkyl indoles has been developed via a redox neutral C-H activation strategy using a traceless nitroso directing group. A broad scope of substituted N-alkyl indoles has been prepared in good to excellent yields using a very simple Rh catalyst system in the absence of an external oxidant or any other additive. Good to excellent regioselectivity has been achieved for asymmetrically disubstituted acetylenes.
- Wang, Chengming,Huang, Yong
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supporting information
p. 5294 - 5297
(2013/11/06)
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- Iodide-catalyzed synthesis of N-nitrosamines via C-N cleavage of nitromethane
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An iodide-catalyzed process to synthesize N-nitrosamines has been developed using TBHP as the oxidant. The mild catalytic system succeeded in cleaving the carbon-nitrogen bond in nitromethane. This methodology uses commercially available, inexpensive catalysts and oxidants and has a wide substrate scope and operational simplicity.
- Zhang, Jie,Jiang, Jiewen,Li, Yuling,Wan, Xiaobing
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p. 11366 - 11372
(2013/12/04)
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- Rhodium(III)-catalyzed N-nitroso-directed C-H olefination of arenes. High-yield, versatile coupling under mild conditions
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N-Nitroso compounds are a versatile class of organic structures that allow expedient access to a diversity of synthetically useful architectures through demonstrated reactivities. We report herein the development of a Rh(III)-catalyzed N-nitroso-directed
- Liu, Baoqing,Fan, Yang,Gao, Yang,Sun, Chao,Xu, Cheng,Zhu, Jin
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supporting information
p. 468 - 473
(2013/02/23)
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- AMIDE DERIVATIVES AND DRUGS
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The present invention provides an amide derivative represented by the following formula [1]: wherein n represents 0 or 1; X represents CR4 or N; Y represents CR6 or N; Z represents CR7 or N; R1 and R2 may be the same or different and each represents hydrogen, optionally substituted alkyl, acyl, optionally substituted aryl, or an optionally substituted aromatic heterocyclic group; R4, R5, R6 and R7 may be the same or different and each represents hydrogen, halogen, hydroxy, amino, alkyl, haloalkyl, alkoxy, monoalkylamino, dialkylamino, arylalkyl, cyano, or nitro; and R3 represents optionally substituted alkylamino, optionally substituted arylamino, or optionally substituted cyclic amino, or a pharmaceutically acceptable salt thereof, and a pharmaceutical composition comprising them as an active ingredient. The compound of the present invention is useful as a TGF-β inhibitor.
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- MEDICINAL COMPOSITION
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The present invention is composed of a pharmaceutical composition for the therapy of nephritis which comprises an amide derivative represented by the following formula [1] or pharmaceutically acceptable salt thereof, as an active ingredient: ???wherein R1 and R2 may be the same or different and each is hydrogen, alkyl which may be substituted, acyl, aryl which may be substituted, or an aromatic heterocyclic group which may be substituted; R3, R4, R5 and R6 may be the same or different and each is hydrogen, halogen, hydroxy, amino which may be substituted, alkyl which may be substituted, alkoxy or nitro and the like; and R7 represents cyclic amino which may be substituted or azabicycloalkylamino which may be substituted. The pharmaceutical composition of the invention is useful for the therapy of nephritis.
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- AMIDE DERIVATIVES AND DRUG COMPOSITIONS
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The present invention is composed of an amide derivative represented by the following formula [1] or pharmaceutically acceptable salt thereof: ???wherein R1 and R2 may be the same or different and each is hydrogen, alkyl which may be substituted, acyl, aryl which may be substituted, or an aromatic heterocyclic group which may be substituted; R3, R4, R5, and R6 may be the same or different and each is hydrogen, halogen, hydroxy, amino which may be substituted, alkyl which may be substituted, alkoxy, or nitro and the like; and R7 represents cyclic amino which may be substituted or azabicycloalkylamino which may be substituted, and a pharmaceutical composition which comprises it as an active ingredient. The compound of the invention is useful as an inhibitor of TGF-β production or an antagonist of TGF-β.
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- Structures of reactive nitrenium ions: Time-resolved infrared laser flash photolysis and computational studies of substituted N-methyl-N-arylnitrenium ions
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A series of para-substituted N-methyl-N-phenylnitrenium ions (N-(4-biphenylyl)-N-methylnitrenium ion, N-(4-chlorophenyl)-N-methylnitrenium ion, N-(4-methoxyphenyl)-N-methylnitrenium ion, and N-(4-methylphenyl)-N-methylnitrenium ion) were generated through photolysis of the appropriately substituted 1-aminopyridinium salt. Laser flash photolysis using UV - vis detection as well as photoproduct analysis verified that the expected nitrenium ions were formed cleanly and rapidly following photolysis. Laser flash photolysis with time-resolved infrared detection allowed for structural characterization of the nitrenium ions through observation of a symmetrical aromatic C=C stretch in the region 1580-1628 cm-1. The specific frequencies reflect the degree of quinoidal character present in each phenylnitrenium ion (i.e., the degree to which the nitrenium ion resembles a 4-iminocyclohexa-2,5-dienyl cation). The 4-methoxy derivative shows the highest frequency C=C stretch, indicating that this strongly π-electron-donating substituent imparts more quinoidal character, and the 4-chloro derivative shows the lowest frequency C=C stretch, suggesting that it possesses the least quinoidal character. Quantum calculations using density functional theory (BPW91/cc-pVDZ) were carried out on the same nitrenium ions. The theoretically derived IR frequencies showed excellent quantitative agreement with the experiment. The computed structures show significant bond length alternation in the phenyl rings, shortened C-N bond lengths, and substantial positive charge delocalization into the phenyl rings. All of these effects are more pronounced with increasing π-donating character of the ring substituent. Arylnitrenium ions are well described as 4-iminocyclohexa-2,5-dienyl cations.
- Srivastava, Sanjay,Ruane, Patrick H.,Toscano, John P.,Sullivan, Michael B.,Cramer, Christopher J.,Chiapperino, Dominic,Reed, Elizabeth C.,Falvey, Daniel E.
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p. 8271 - 8278
(2007/10/03)
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- Reactions of peroxynitrite with N,N-dimethyl-p-toluidine and 1,4-naphthoquinone. Evidence for heterolytic cleavage of a nitrogen-oxygen bond in peroxynitrous acid
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Peroxynitrite (ONOO-) has been found to react with the title amine 1 and quinone 5 to form N-nitrosoamine 2 and 2,3-epoxide 6, respectively, in accord with the in situ generation of the nitrosonium and hydroperoxide ions as the respective reactive species.
- Nonoyama, Nobuaki,Hisatome, Kaori,Shoda, Chizuru,Suzuki, Hitomi
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p. 6939 - 6940
(2007/10/03)
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- Observation of a single-pot aromatic reductive denitration
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4,N,N-Trimethyl-3-nitrobenzenamine gave reductive denitration products (ca. 28%) upon treatment with n-butyl nitrite in the presence of catalytic amounts of ammonium chloride and water in an unprecedented one-reagent single-pot process. The three isomeric N,N-dimethylnitrobenzenamines showed the same behaviour to a much lesser extent; the ortho isomer was partially (7%) transformed into 1-methylbenzotriazole.
- Giumanini, Angelo G.,Verardo, Giancarlo
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p. 469 - 473
(2007/10/03)
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- Electrophilic α-p-tolylhydrazonylation of tert-butyl alkanoates and tertiary alkanamides with tert-butyl p-tolylazo sulfide
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The reactions of the enolates of tert-butyl alkanoates 2 and N,N-dialkylalkanamides 3 with tert-butyl p-tolylazo sulfide 1 in THF furnish good yields of the corresponding α-p-tolylhydrazonylated esters 4 and amides 5. Results are reported showing the possible transformation of 4 and 5 into the N-methylated derivatives 8 and 9 and the subsequent deblocking of the protected carbonyl function to the corresponding 2-oxoalkanoates 10 and 2-oxoalkanamides 11.
- Dell'Erba, Carlo,Novi, Marino,Petrillo, Giovanni,Tavani, Cinzia
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p. 5889 - 5898
(2007/10/03)
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- Succinimidylation and nitration of aromatic compounds by photolysis with N-nitrosuccinimide
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N-Nitrosuccinimide (S-NO2) engages in weak charge transfer complexes with aromatic compounds (ArH).Upon photolysis with light of λ > 345 nm in dichloromethane, electron transfer within the charge transfer complex leads to the triad -NO2>from which products of eventual succinimidylation and/or nitration develop by initial attack of succinimide anion upon the radical cation.Photolysis in the presence of trifluoroacetic acid (0.4 mol dm-3) causes inactivation of S- by protonation, making EPR detection of ArH-radical cations or radicals cations formed by its further transformations possible.In acetonitrile, trifluoroacetic acid is too weak effectively to protonate S-, whereas addition of stronger acids again leads to the development of EPR spectra of ArH-radical cation in the case of 9,10-dimethylanthracene, the intensity increasing with decreasing pK of the acid.An X-ray crystal structure is reported for N-nitrosuccinimide.
- Calvert, Jane,Eberson, Lennart,Hartshorn, Michael P.,Svensson, Jan O.
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p. 645 - 652
(2007/10/02)
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- Transnitrosation by N-aryl-N-nitrosoureas; NO-carrying O-nitrosoisourea
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Transfer of nitroso groups, so-called transnitrosation, from aromatic N-nitroso compounds such as N-nitrosoureas, N-nitrosamides and N-nitrosamines, to aromatic amines or ureas was observed under non-acidic conditions at room temperature. Sterically hindered 3,3-dibenzyl-1-(4-tolyl)-1-nitrosourea (1a) rapidly nitrosates indoline, N-alkylanilines or 3-methyl-1-(4-tolyl)urea to give their N-nitroso derivatives. In the case of N,N-dimethylanilines, nitrosative demethylation occurs to give N-methyl-N-nitrosanilines. The transnitrosation is accelerated by electron-releasing groups on the nitroso acceptors, N-alkylanilines. The transnitrosation mechanism is considered to be as follows: N-nitrosourea (1) thermally decomposes to nitric oxide and ureidyl radical followed by formation of an O-nitrosoisourea intermediate (10), which acts as an NO-carrying agent and nitrosates anilines or ureas.
- Tanno,Sueyoshi,Miyata
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p. 1760 - 1767
(2007/10/02)
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- N-Dealkylation-N-nitrosation of Tertiary Aromatic Amines by n-Butyl Nitrite
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N,N-Dialkyl aromatic amines with a variety of ring substituents are N-dealkylated and N-nitrosated efficiently by n-butyl nitrite/ammonium chloride/water at reflux temperature.Ring nitrosation was never observed, but minor amounts of m- and p-nitro amines and/or nitrosamines were formed in some cases.Ring nitration is rather a reaction of the initial substrate than a process occurring on formed nitrosamines.The leaving propensities of the initial N-substituents to yield nitrosamines were in the order benzyl >> methyl >> alkyl.Key Words: Nitrosamines; N-Dealkylation; N-Nitrosation; C-Nitration; Alkyl nitrite.
- Verardo, Giancarlo,Giumanini, Angelo G.,Strazzolini, Paolo
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p. 7845 - 7852
(2007/10/02)
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- Unusual Rate-limiting Proton Transfer in the Acid-catalysed Reactions of N-Nitroso Compounds
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For both N-methyl-N-nitrosoaniline and N-nitrosodiphenylamine, the catalytic effect of halide ion, thiocyanate ion, and thiourea in the denitrosation reaction in acid solution disappears at high nucleophile concentrations.This suggests a change to an earlier rate-limiting step.The data, including the variation of rate constant with acidity, are quantitatively in accord with a reaction mechanism involving protonation of the nitosamine followed by nucleophilic attack, either stage being rate limiting, depending on the reactivity and concentration of the nucleophile.The kinetic solvent isotope effect kH2O/kD2O decreases from 1.59 at 0.43M-thiourea to 0.71 at 0.015M-thiourea, which is consistent with a change from general acid catalysis at high to specific hydrogen ion catalysis at low .Substituent effects at the amino-nitrogen atom and also in the 4-position of a phenyl substituent are very amall, the largest effect being a three-fold reduction in rate constant effected by a 4-NO2 group.These results are in accord with the known dipolar nature of nitrosamines.There is a close analogy between this system and the acid-catalysed cleavage reaction of carbamate derivatives.A similar mechanism is proposed involving a pre-association of the reactants forming a hydrogen-bonded intermediate.
- Al-Kaabi, Sharifa S.,Hallett, Geoffrey,Meyer, Thomas A.,Williams, D. Lyn H.
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p. 1803 - 1808
(2007/10/02)
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