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1.
A variety of novel N‐t‐butyl‐N′‐aminocarbonyl‐N‐(substituted)benzoylhydrazines containing α‐aminoalkylphosphonate groups were synthesized. Treatment of α‐aminoalkylphosphonates with triphosgene yielded α‐isocyanatoalkylphosphonates, and subsequent addition with N‐t‐butyl‐N‐substituted benzoylhydrazines provided the title compounds in a one‐pot procedure with good yields. The triphosgene‐mediated reaction for the synthesis of α‐isocyanatoalkylphosphonates enjoys a number of advantages: the reaction is carried out under mild condition in good yield, triphosgene is relatively safe to handle because of its low vapor pressure and high stability, and the experimental procedure is simple. This method can be applicable to the synthesis of other α‐isocyanatoalkyl‐phosphonates and urylenediphosphonates. The structures of all of the products and by‐products were confirmed by 1H NMR, 31P NMR, IR and mass spectroscopy, and elemental analysis. We also found that some of the compounds possess potential antitobacco mosaic virus (TMV) activities and anticancer activities. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:68–72, 2001 相似文献
2.
Kou P. Kawahara Wataru Matsuoka Hideto Ito Kenichiro Itami 《Angewandte Chemie (International ed. in English)》2020,59(16):6383-6388
Nitrogen‐containing polycyclic aromatic compounds (N‐PACs) are an important class of compounds in materials science. Reported here is a new aza‐annulative π‐extension (aza‐APEX) reaction that allows rapid access to a range of N‐PACs in 11–84 % yields from readily available unfunctionalized aromatics and imidoyl chlorides. In the presence of silver hexafluorophosphate, arenes and imidoyl chlorides couple in a regioselective fashion. The follow‐up oxidative treatment with p‐chloranil affords structurally diverse N‐PACs, which are very difficult to synthesize. DFT calculations reveal that the aza‐APEX reaction proceeds through the formal [4+2] cycloaddition of an arene and an in situ generated diarylnitrilium salt, with sequential aromatizations having relatively low activation energies. Transformation of N‐PACs into nitrogen‐doped nanographenes and their photophysical properties are also described. 相似文献
3.
The rates of gas‐phase elimination of N‐ethyl (1), N‐isopropyl (2), N‐t‐butyl (3) substituted 2‐aminopyrazine and N‐ethyl (4), N‐isopropyl (5), and N‐t‐butyl (6) substituted 2‐aminopyrimidine have been measured. The compounds undergo unimolecular first‐order pyrolytic reactions. The relative rates of the primary:secondary;tertiary alkyl homologues at 600 K are 1:14.4:38.0 for the pyrazines and 1:20.8:162.5 for the pyrimidines, respectively. The reactivities of these compounds have been compared with those of the alkoxy analogues and with each other. Product analyses, together with the kinetic data, were used to outline a feasible pathway for the elimination reaction of the compounds under study. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 403–407, 2000 相似文献
4.
Almaz Zagidullin Vasili Miluykov Oleg Sinyashin Peter Lnnecke Evamarie Hey‐Hawkins 《Heteroatom Chemistry》2014,25(1):28-34
The [4+2] cycloaddition reaction of 1‐alkyl‐1,2‐diphospholes ( 1 ) with N‐phenylmaleimide proceeds at 25°С in toluene to give 1,7‐diphosphanorbornenes ( 2 ) as anti‐endo isomer only. Oxidation of 2 with air at room temperature or thionation with excess of sulfur at 80°С results in the formation of mixed valent PIII, PV 7‐oxo(thia)‐1,7‐diphosphanorbornenes ( 3 , 4 ) in high yield. The polycyclic compounds 3 and 4 are air stable and have small sums of valence angles at the phosphorus atoms. 相似文献
5.
Agnieszka Bogdanowicz Henryk Foks Katarzyna Gobis Ewa Augustynowicz‐Kopec 《Heteroatom Chemistry》2012,23(2):223-230
The synthesis of N′‐methyl‐4‐(pyrrolidin‐1‐yl)picolinohydrazide and N′‐methyl‐pyrimidine‐2‐carbohydrazide derivatives ( 5a and 5b ) was carried out. These compounds were used as starting materials to obtain methyl N′‐methylhydrazinecarbodithioates 6a and 6b , which, on reaction with either triethylamine or hydrazine, gave corresponding 1,3,4‐oxadiazioles 7a and 7b or 1,2,4‐triazoles 9a and 9b with the free NH2 group at the N‐4 position, respectively. Compounds 8a – e , particularly containing cyclic amines at N‐4 of the 1,2,4‐triazole ring, were also obtained. Synthesized compounds were tested in vitro for their activity against Mycobacterium tuberculosis. The structure–activity relationship analysis for obtained compounds was done. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:223–230, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21008 相似文献
6.
Ren‐Ming Hu Dong‐Yang Han Ning Li Jie Huang Yu Feng Da‐Zhen Xu 《Angewandte Chemie (International ed. in English)》2020,59(10):3876-3880
Presented herein is the first direct alkylation and hydroxylation reaction between two different C(sp3)?H bonds, indolin‐2‐ones and alkyl‐substituted N‐heteroarenes, through an oxidative cross‐coupling reaction. The reaction is catalyzed by a simple iron salt under mild ligand‐free and base‐free conditions. The reaction is environmentally benign, employs air (molecular oxygen) as the terminal oxidant and oxygen source for the synthesis of O‐containing compounds, and produces only water as the byproduct. 相似文献
7.
Rhodium(II)‐Catalyzed Intramolecular Cycloisomerizations of Methylenecyclopropanes with N‐Sulfonyl 1,2,3‐Triazoles 下载免费PDF全文
Kai Chen Zi‐Zhong Zhu Yong‐Sheng Zhang Dr. Xiang‐Ying Tang Prof. Min Shi 《Angewandte Chemie (International ed. in English)》2014,53(26):6645-6649
A novel rhodium(II)‐catalyzed tandem cycloisomerization of methylenecyclopropanes (MCPs) with N‐sulfonyl 1,2,3‐triazoles is disclosed. The reaction produces a series of highly functionalized polycyclic N heterocycles via a rhodium imino carbene intermediate. A distinct feature of this divergent synthesis is that different types of substrates control the reaction pathways. Moreover, several interesting transformations of these products to construct diazabicyclo[3.2.1]octane derivatives are also reported. 相似文献
8.
A series of novel N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐diacylhydrazines were synthesized by the reaction of chlorosulfenyl[O‐(1‐methylthioethylimino)‐N‐methylcarbamate] with N‐tert‐butyl‐N,N′‐diacylhydrazine in the presence of sodium hydride. The reaction of sulfur dichloride with O‐(1‐methylthioethylimino)‐N‐methylcarbamate (Methomyl) in the presence of pyridine to yield chlorosulfenyl[O‐(1‐methylthioethylimino)‐N‐methylcarbamate] was reported for the first time. X‐ray single crystal diffraction of N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐dibenzoylhydrazine demonstrated that the parent compounds N‐tert‐butyl‐N,N′‐dibenzoylhydrazine and O‐(1‐methylthioethylimino)‐N‐methylcarbamate were combined by N S N band to give the product. Their larvicidal activities against Oriental armyworm and Aphis laburni were evaluated. All of them exhibited excellent larvicidal activities against Oriental armyworm, with some of them showing higher larvicidal activities than the parent diacylhydrazines. Toxicity assays indicated that the products show knockdown activity for O‐(1‐methylthioethylimino)‐N‐methylcarbamate at higher concentration and insect growth regulators' activities of diacylhydrazines at lower concentrations. At the same time, the products possess insecticidal activities against the aphids. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:631–636, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20360 相似文献
9.
Gold‐Catalyzed Formal C−C Bond Insertion Reaction of 2‐Aryl‐2‐diazoesters with 1,3‐Diketones 下载免费PDF全文
《化学:亚洲杂志》2018,13(18):2606-2610
The transition‐metal‐catalyzed formal C−C bond insertion reaction of diazo compounds with monocarbonyl compounds is well established, but the related reaction of 1,3‐diketones instead gives C−H bond insertion products. Herein, we report a protocol for a gold‐catalyzed formal C−C bond insertion reaction of 2‐aryl‐2‐diazoesters with 1,3‐diketones, which provides efficient access to polycarbonyl compounds with an all‐carbon quaternary center. The aryl ester moiety plays a crucial role in the unusual chemoselectivity, and the addition of a Brønsted acid to the reaction mixture improves the yield of the C−C bond insertion product. A reaction mechanism involving cyclopropanation of a gold carbenoid with an enolate and ring‐opening of the resulting donor–acceptor‐type cyclopropane intermediate is proposed. This mechanism differs from that of the traditional Lewis‐acid‐catalyzed C−C bond insertion reaction of diazo compounds with monocarbonyl compounds, which involves a rearrangement of a zwitterion intermediate as a key step. 相似文献
10.
Dr. Yoshiyuki Manabe Hiroki Shomura Naoya Minamoto Dr. Masahiro Nagasaki Yohei Takakura Prof. Katsunori Tanaka Prof. Alba Silipo Prof. Antonio Molinaro Prof. Koichi Fukase 《化学:亚洲杂志》2018,13(12):1544-1551
The chemical synthesis of a bisecting N‐acetylglucosamine (GlcNAc)‐containing N‐glycan was achieved by a convergent synthetic route through [4+2] and [6+2] glycosylations. This synthetic route reduced the number of reaction steps, although the key glycosylations were challenging in terms of yields and selectivities owing to steric hindrance at the glycosylation site and a lack of neighboring group participation. The yields of these glycosylations were enhanced by stabilizing the oxocarbenium ion intermediate through ether coordination. Glycosyl donor protecting groups were explored in an effort to realize perfect α selectivity by manipulating remote participation. The simultaneous glycosylations of a tetrasaccharide with two disaccharides was investigated to efficiently construct a bisecting GlcNAc‐containing N‐glycan. 相似文献
11.
Enantioselective Oxidative Gold Catalysis Enabled by a Designed Chiral P,N‐Bidentate Ligand 下载免费PDF全文
Dr. Kegong Ji Zhitong Zheng Zhixun Wang Prof. Dr. Liming Zhang 《Angewandte Chemie (International ed. in English)》2015,54(4):1245-1249
A newly developed P,N‐bidentate ligand enables enantioselective intramolecular cyclopropanation by a reactive α‐oxo gold carbene intermediate generated in situ. The ligand design is based on our previously proposed structure (with a well‐organized triscoordinated gold center) of the carbene intermediate in the presence of a P,N‐bidentate ligand. A C2‐symmetric piperidine ring was incorporated in the ligand as the nitrogen‐containing moiety. A range of racemic transformations of α‐oxo gold carbene intermediates have been developed recently, and this new class of chiral ligands could enable their modification for asymmetric synthesis, as demonstrated in this study. 相似文献
12.
Yajun Li Dr. Jiangtao Zhu Lisi Zhang Prof. Dr. Yongming Wu Prof. Dr. Yuefa Gong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(25):8294-8299
A highly efficient method for the synthesis of fluorine‐containing multisubstituted phenanthridines through Rh‐catalyzed alkyne [2+2+2] cycloaddition reactions has been developed. This method exhibits excellent functional‐group compatibility. When a bromodifluoromethyl group, rather than a trifluoromethyl group, was employed in the cycloaddition reaction, more‐complicated polycyclic compounds were obtained through tandem Rh‐catalyzed cycloaddition/C? H difluoromethylenation. This route provides convenient access to fluorine‐containing polycyclic compounds. 相似文献
13.
An intriguing C?N transformation involving a catalyst‐free N‐alkylation/N′‐arylation process in a multicomponent reaction with secondary amines, cyclic tertiary amines and electron‐deficient aryl halides has been described. In this case, the N‐alkylation of secondary amines, utilizing cyclic tertiary amines as alkyl group sources, is enabled by a facile C?N cleavage. Such an operationally simple method could facilitate access to aromatic aminoalkyl amines, nitrogen‐containing bioactive molecules, in good to excellent yields. 相似文献
14.
Phosphorylation of N‐arylpyrroles with phosphorus tribromide proceeds regioselectively at the position 2 of the heterocyclic system. A 2‐to‐3 migration of the dibromophosphino group has been discovered, with its ease depending on the electronic nature of a substituent on the phenyl ring, solvent polarity, and the presence of pyridine hydrobromide in the reaction mixture. Further phosphorylation of 2‐ and 3‐monophosphorylated N‐arylpyrroles regioselectively involves the respective positions 4 and 5 of the heterocycle and is governed by the electron‐acceptor effect of the phosphorus‐containing substituent. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:223–228, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10012 相似文献
15.
A series of new N‐benzoyl‐N‐tert‐butyl‐N′‐(β‐triphenylgermyl)propionylhydrazines were synthesized by the condensation reaction of β‐triphenylgermyl propanoic acid with N‐benzoyl‐N‐tert‐butylhydrazines in good yields by using N,N′‐dicyclohexylcorbodiimide as dehydrating agent. These title compounds were evaluated for molting hormone mimicking activity. The results of bioassay showed that the compounds exhibit moderate larvicidal activity, and toxicity assays indicated that the title compounds can induce a premature, abnormal and lethal larval molt. We found that the title compounds possess potential anticancer activities in vitro. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
16.
Abdullah A. Al‐Karim Al‐Shara'ey 《中国化学会会志》2004,51(3):547-552
6‐Aryl‐5‐cyano‐4‐pyrimidinone‐2‐thion derivatives 1a‐c reacted with methyl iodide (1:2) to give the corresponding 2‐S,N‐dimethyl pyrimidine‐4‐one derivatives 2a‐c . Compounds 2a‐c were in turn, reacted with hydrazine hydrate to give the sulfur free reaction products 3a‐c . These reaction products were taken as the starting materials for the synthesis of several new heterocyclic derivatives. Reaction of 3a‐c with acetic anhydride and formic acid gave pyrimido triazines 4a‐c and 7a‐c , respectively. Their reactions with active methylene containing reagents gave the corresponding 2‐(1‐pyrazonyl)‐N‐methyl pyrimidine derivatives 9a‐c and 10a‐c , respectively. Their reactions with aromatic aldehydes afforded the corresponding 2‐hydrazono pyrimidine derivatives 11a‐c . The structure of these reactions products were established based on both elemental analysis and spectral data studies. 相似文献
17.
A series of novel N‐glycosyl‐N′‐pyrazolylmethylene aminothioureas ( 4a‐4e, 5a‐5e ) were synthesized from N‐glycosyl‐N′‐aminothioureas ( 2a‐2d ) and 4‐formylpyrazole ( 3a‐3e ). Activated 4Å molecular sieves were adopted for dehydrated reagent to improve the reaction rate and yield. The structures of the new compounds were identified on the basis of IR, 1H NMR and MS spectra. Simultaneously, the compounds were detected by fluorescence spectrophotometer and had preferable fluorescence activity, so they can be selected as a kind of novel fluorescence labeled derivative of sugar. 相似文献
18.
Firouz Matloubi Moghaddam Salman Taheri Zohreh Mirjafary Hamdollah Saeidian Mostafa Kiamehr Mohsen Tafazzoli 《Helvetica chimica acta》2011,94(1):142-147
The efficient synthesis of bridged polycyclic naphthooxazocines 3 via addition of naphthalenols 1 as a bis‐nucleophile to N‐alkylquinolinium salts 2 is described (Scheme 1 and Table 2). This new approach provides a powerful entry into polycyclic structures containing bicyclic N,O‐acetals related to bioactive compounds. 相似文献
19.
Base‐Promoted/Gold‐Catalyzed Intramolecular Highly Selective and Controllable Detosylative Cyclization 下载免费PDF全文
Chenghao Zhu Dr. Lin Qiu Guangyang Xu Dr. Jian Li Prof. Dr. Jiangtao Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):12871-12875
A highly selective, controllable and synthetically useful base‐promoted intramolecular detosylative cyclization of bis‐N‐tosylhydrazones has been achieved, affording N‐containing heterocycles and cyclic olefins under transition‐metal‐free or gold‐catalyzed procedures, respectively. Moreover, an effective and practical metal‐free or gold‐catalyzed approach to synthesize polycyclic aromatic compounds is also reported. 相似文献
20.
Metal‐Free Cyclization of ortho‐Nitroaryl Ynamides and Ynamines towards Spiropseudoindoxyls 下载免费PDF全文
Niels Marien B. Narendraprasad Reddy Freija De Vleeschouwer Steven Goderis Prof. Kristof Van Hecke Prof. Guido Verniest 《Angewandte Chemie (International ed. in English)》2018,57(20):5660-5664
An efficient metal‐free cascade reaction between 1‐dibromovinyl‐2‐nitro‐substituted arenes and secondary amines results in the formation of polycyclic pseudoindoxyls in a single step. The reaction mechanism leading to these fused ring systems was investigated, and is believed to involve the initial formation of nitroarylated ynamines/ynamides. These intermediates cycloisomerize towards N‐alkenyl‐tethered 2‐aminoisatogens via a carbene intermediate as demonstrated by QTAIM (quantum theory of atoms in molecules) and ELF (electron localization function) analysis. A subsequent intramolecular dipolar cycloaddition afforded the title compounds. 相似文献