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1.
Yukihiro Mitsuda Takahiro Uno Masataka Kubo Takahito Itoh 《Journal of polymer science. Part A, Polymer chemistry》2005,43(21):5195-5206
Spontaneous reactions of an electron‐accepting substituted quinodimethane, 1‐(2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione‐5‐ylidene)‐4‐(dicyanomethylene)‐2,5‐cyclohexadiene, with p‐substituted, α‐substituted, and β‐substituted styrenes were investigated. When p‐substituted styrenes were used as comonomers, no spontaneous reactions took place for styrenes with an electron‐accepting p substituent such as COOMe and CN groups, and both terpolymers and cycloadducts were formed for the other p‐substituted styrenes. When α‐substituted and β‐substituted styrenes were used as comonomers, no reactions occurred for α‐ and β‐substituted styrenes with a bulky phenyl group, and spontaneous reactions took place for those with a smaller methyl group. The reaction products were an alternating copolymer for α‐substituted styrene and both terpolymers and 5‐ethylidene‐2,5‐dimethyl‐1,3‐dioxane‐4,6‐dione for β‐substituted styrenes. The position of the methyl group in the styrenes significantly affected the product formation. This behavior in the spontaneous reactions was discussed on the basis of the ability of formation of the zwitterionic tetramethylene intermediate and its conformation, determined by polar and steric effects of the substituents in the substituted styrenes. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5195–5206, 2005 相似文献
2.
Yoshio Ueno Keiichi Maeda Jinya Koshitani Takatoshi Yoshida 《Journal of heterocyclic chemistry》1982,19(1):189-191
The substituted 6-bromo and 6-chloro-5H-benzo[a]phenoxazin-5-ones, prepared by condensation of substituted 2-aminophenols with 2,3-dibromo or 2,3-dichloro-1,4-naphthoquinone in methanolic potassium hydroxide solution, have been dehalogenated to substituted 5H-benzo[a]phenoxazin-5-ones in the presence of sodium hydrosulfite dissolved in aqueous pyridine under nitrogen atmosphere. 相似文献
3.
Substituted Tetraaza‐ and Hexaazahexacenes and their N,N′‐Dihydro Derivatives: Syntheses,Properties, and Structures
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Jens U. Engelhart Dr. Benjamin D. Lindner Manuel Schaffroth David Schrempp Olena Tverskoy Prof. Uwe H. F. Bunz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8121-8129
The palladium‐catalyzed coupling of a substituted o‐diaminoanthracene and a substituted o‐diaminophenazine to substituted 2,3‐dichloroquinoxalines furnishes 10 differently substituted N,N′‐dihydrotetraaza‐ or ‐hexaazahexacenes with the quinoxaline group of the azaacenes carrying fluorine, chlorine, or nitro groups. The N,N′‐dihydrotetraazahexacenes with hydrogen, chlorine, and fluorine subtituents are oxidized to azaacenes, whereas only the parent N,N′‐dihydrohexaazahexacenes, with hydrogen substituents, are oxidized by MnO2. The resultant azaacenes are characterized by their optical and spectroscopic data. In addition, single‐crystal X‐ray structures have been obtained for the parent tetraazahexacenes and their difluoro‐substituted derivatives. The di‐ and tetrachloro derivatives of the N,N′‐dihydrohexaazahexacene have also been structurally characterized. 相似文献
4.
A. Shafiee J. Shahbazi Mojarrad M. A. Jalili H. R. Adhami F. Hadizadeh 《Journal of heterocyclic chemistry》2002,39(2):367-373
Starting from readily available p‐substituted‐benzylamines a series of ethyl 2‐alkylthio‐1‐substituted‐ben‐zylpyrrolo[2,3‐d]imidazole‐5‐carboxylates was prepared. In addition, starting from 2‐alkyl‐4(or 5)‐formylimidazoles and methyl 4′‐bromomethylbiphenyl‐2‐carboxylate a series of methyl substituted‐pyrrolo[2,3‐d]imidazole‐5‐carboxylates and methyl substituted‐pyrrolo[3,2‐d]imidazole‐5‐carboxylates was prepared. 相似文献
5.
Salvador Vega María Esther Arranz Vicente J. Arn 《Journal of heterocyclic chemistry》2005,42(5):763-773
A series of 2‐substituted 2H‐thieno[3,4‐e][1,2,4]thiadiazin‐3(4H)‐one 1,1‐dioxides ( 2 ), 2‐substituted 2H‐thieno[2,3‐e][1,2,4]thiadiazin‐3(4H)‐one 1,1‐dioxides ( 3 ), 2‐substituted 4,6‐dihydropyrazolo[4,3‐e]‐[1,2,4]thiadiazin‐3(2H)‐one 1,1‐dioxides ( 4 ), 2‐substituted 2,3‐dihydrooxazolo[3,2‐b]thieno[3,4‐e]‐[1,2,4]thiadiazine 5,5‐dioxides, ( 5 ), 6‐substituted 6,7‐dihydro‐2H‐oxazolo[3,2‐b]pyrazolo[4,3‐e][1,2,4]thia‐diazine 9,9‐dioxides ( 6 ) and 7‐substituted 6,7‐dihydro‐2H‐oxazolo[3,2‐b]pyrazolo[4,3‐e][1,2,4]thiadiazine 9,9‐dioxides ( 7 ) were synthesized as potential psychotropic agents. 相似文献
6.
Hanzhen Yuan Lin Wang Gongzhen Cheng Sui Zhao Shizhen Mao Jiayong Yu Youru Du 《Acta Physico》2006,22(12):1435-1440
Micellization of a series of newly synthesized dialkyl benzene sulfonates was studied using proton chemical shift changes, spin-lattice and spin-spin relaxation NMR spectroscopy, and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY). The o-substituted chains are normal alkyl chains with varying lengths, and the m-substituted ones are branched alkyl chains. The results showed that the longer the o-substituted normal alkyl chain, the more the methylene groups participated in the formation of the rigid surface layers of the hydrophobic micellar cores. Consequently, the larger was the area per molecule adsorbed on the interface between oil and water at saturation. The branched m-substituted alkyl chains of the dialkyl benzene sulfonates were less tightly packed than the o-substituted normal alkyl chains in the hydrophobic micellar cores. The shorter the m-substituted branched alkyl chains, the looser they were packed in the hydrophobic micellar cores. The relative arrangement of the surfactant molecules in the micelles was elucidated. 相似文献
7.
Activated quinones: O- versus C-addition of phenols. New regiospecific syntheses of xanthones, thioxanthones and N-methyl-9-acridones The acid catalyzed reaction of phenols with activated quinones, e.g. 2-methoxycarbonyl-1, 4-benzoquinone or 2-acetyl-1, 4-benzoquinone, leads to substituted biphenylderivatives (C, C-addition) as has been previously described [1]. O, C-Addition of phenols has now been achieved by using 2-methoxypyridin or 4-dimethyl-aminopyridin [4] as basic catalysts. The resulting substituted diphenylethers can serve as convenient starting materials for regiospecific syntheses of substituted xanthones, especially for 1, 4-dimethoxyxanthones. Arylthiols and N-methyl-N-arylamines also react readily with activated quinones to give substituted di-aryl-thioethers and N-methyl-N, N-diarylamines respectively; both types of compounds are convenient materials for regiospecific syntheses of substituted thioxanthones and N-methyl-9-acridones. 相似文献
8.
A Convenient Synthesis of N‐Aryl Benzamides by Rhodium‐Catalyzed ortho‐Amidation and Decarboxylation of Benzoic Acids
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Dr. Xian‐Ying Shi Ke‐Yan Liu Juan Fan Xue‐Fen Dong Prof. Dr. Jun‐Fa Wei Prof. Dr. Chao‐Jun Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):1900-1903
The rhodium‐catalyzed amidation of substituted benzoic acids with isocyanates by directed C?H functionalization followed by decarboxylation to afford the corresponding N‐aryl benzamides is demonstrated, in which the carboxylate serves as a unique, removable directing group. Notably, less common meta‐substituted N‐aryl benzamides are generated readily from more accessible para‐ or ortho‐substituted groups by employing this strategy. 相似文献
9.
α‐Oxy/thio substituted β‐keto esters were synthesized through an efficient cross‐Claisen condensation of oxy/thio substituted acetic acid ethyl esters with acid chlorides, which in turn converted in situ into 4‐oxy/thio substituted‐1H‐pyrazol‐5(4H)‐ones by the addition of hydrazine and its derivatives. This method has been found to be extremely fast, general, and useful toward the synthesis of inaccessible pyrazolones and synthetically demanding 4‐oxy/thio substituted pyrazolones. J. Heterocyclic Chem., (2011). 相似文献
10.
meso‐Ester and Carboxylic Acid Substituted BODIPYs with Far‐Red and Near‐Infrared Emission for Bioimaging Applications
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Yong Ni Prof. Lintao Zeng Dr. Nam‐Young Kang Prof. Kuo‐Wei Huang Prof. Liang Wang Zebing Zeng Prof. Young‐Tae Chang Prof. Jishan Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(8):2301-2310
A series of meso‐ester‐substituted BODIPY derivatives 1–6 are synthesized and characterized. In particular, dyes functionalized with oligo(ethylene glycol) ether styryl or naphthalene vinylene groups at the α positions of the BODIPY core ( 3 – 6 ) become partially soluble in water, and their absorptions and emissions are located in the far‐red or near‐infrared region. Three synthetic approaches are attempted to access the meso‐carboxylic acid (COOH)‐substituted BODIPYs 7 and 8 from the meso‐ester‐substituted BODIPYs. Two feasible synthetic routes are developed successfully, including one short route with only three steps. The meso‐COOH‐substituted BODIPY 7 is completely soluble in pure water, and its fluorescence maximum reaches around 650 nm with a fluorescence quantum yield of up to 15 %. Time‐dependent density functional theory calculations are conducted to understand the structure–optical properties relationship, and it is revealed that the Stokes shift is dependent mainly on the geometric change from the ground state to the first excited singlet state. Furthermore, cell staining tests demonstrate that the meso‐ester‐substituted BODIPYs ( 1 and 3 – 6 ) and one of the meso‐COOH‐substituted BODIPYs ( 8 ) are very membrane‐permeable. These features make these meso‐ester‐ and meso‐COOH‐substituted BODIPY dyes attractive for bioimaging and biolabeling applications in living cells. 相似文献
11.
Jin‐Jun Wang Young Key Shim Gui‐Ji Jiang Kimiaki Imafuku 《Journal of heterocyclic chemistry》2003,40(6):1075-1079
Methyl pyropheophorbide‐a (MPPa) ( 1 ) was converted to two aldehydes, methyl 2‐formylmethyl‐2‐devinylpyropheophorbide‐a ( 2 ) and methyl 2‐formyl‐2‐devinylpyropheophorbide‐a ( 3 ). The former 2 reacted with active methylene compounds having a cyano function in the presence of sulfur to afford thiophene‐substituted chlorins 5a‐c and reacted with arylhydrazines to yield indole‐substituted chlorins 6a‐d . From the latter 3 , a α‐diketo chlorin 7 was obtained via Wittig reaction and oxidation. Compound 7 reacted with o‐phenylenediamine to afford 2‐quinoxalyl‐substituted pyropheophorbide‐a 8. The reaction of MPPa ( 1 ) with anthranilamide to give a spiro‐substituted compound 9 . 相似文献
12.
Frdric Leroux TilmanU. Hutschenreuter Cline Charrire Rosario Scopelliti RolfW. Hartmann 《Helvetica chimica acta》2003,86(7):2671-2686
3,3′,5,5′‐ And 2,2′,6,6′‐tetrafluoro‐substituted 1‐[(1,1′‐biphenyl]‐4‐yl)methyl]‐1H‐imidazoles were synthesized as inhibitors of 17α‐hydroxylase‐C17,20‐lyase (P450 17, CYP 17). P450 17 is the key enzyme of androgen biosynthesis. Its inhibition is a novel therapeutic approach for treatment of prostate cancer. To increase the so‐far insufficient in vivo lifetime of such compounds, the metabolically sensitive positions were blocked by F‐substitution. The meta‐ and ortho‐F‐substituted compounds were prepared by selective metallation or halogen/metal permutation reactions performed on symmetrically substituted 1,1′‐biphenyls. Compared with the halogen‐free compounds, the ortho‐F‐substituted derivatives did not match the activity, whereas the meta‐F‐substituted isomers equaled or surpassed the latter. 相似文献
13.
Alkyl 2-(substituted cinnamoylamino)-3-dimethylaminopropenoates 5, prepared either from glycine ( 1 ) and substituted cinnamoyl chlorides 2 via oxazol-5(4H)-ones 4 , or from cinnamoylglycinate with t-butoxy-bisdimethylaminomethane, were transformed by nitrosation into 5-substituted-1,2,4-oxadiazole-3-carboxylates 8 . The formation of alkyl N-cinnamoyloxalic acid hydroxyimidic amides 7, which were isolated as intermediates, represent a novel synthesis of N-acyl substituted hydroxyimidic amides. 相似文献
14.
Abstract The benzyl substituted ethyl thioglycoside of L-fucose was found to be a more reactive donor compared to 2-O-benzyl substituted p-tolyl thioglycoside of D-galactose. Using the benzyl substituted ethyl thioglycoside of L-fucose (8), as a donor and the suitably substituted p-tolyl thioglycoside of D-galactose (7) as acceptor, the p-tolyl thioglycoside of the disaccharide, 9, was prepared. This disaccharide donor was allowed to react with a suitably protected galactopyranosyluronic acid acceptor, 16, to give the trisaccharide repeating unit of the K-antigen from Klebsiella type 63. 相似文献
15.
Various new substituted and fused pyridotriazepine analogues have been synthesized via different synthetic pathways. Among which are different heterocyclic compounds consisting of the pyridotriazepine backbone fused to different heterocyclic systems comprising either substituted pyrimidine nucleus such as compounds 3 – 9 or substituted 4‐aminopyridine nucleus such as compounds 10 – 16 . Besides, the tetrahydroquinoline derivative 17 , [1,2,4]triazolopyrimidine derivative 18 , thienodiazocine derivative 19 , dihydrobenzofuropyridine derivative 20 , and the substituted pyrrole derivative 21 were synthesized. In addition, different substituted pyridotriazepine derivatives as indicated in compounds 22 – 25 were designed and synthesized. Twenty‐five of the newly synthesized compounds were subjected to in vitro anticancer screening against mammalian colon carcinoma HCT‐116 cell line using Cisplatin as a reference drug. The anticancer activity screening results revealed that among the tested compounds, the tetrahydropyrido[1,2‐b]pyrimido[4,5‐e][1,2,4]triazepine derivative 4 substituted at C2 and C4 positions with S‐methyl and amino moieties, respectively, and the 2,4‐dithioxo analogue 9 and the 2‐thioxodipyrido[1,2‐b:2′,3′‐e][1,2,4]triazepine derivative 11 substituted at C3 and C4 with a cyano and amino moieties, respectively, exhibited moderate to strong anticancer activity against mammalian colon carcinoma HCT‐116 cell line. 相似文献
16.
A. Shafiee P. Shabani M. Vosooghi A. Foroumadi 《Journal of heterocyclic chemistry》2005,42(5):1011-1015
A series of substituted N‐(4‐substituted‐benzoyl)‐N‐[3‐(1‐methyl‐1H‐imidazol‐2‐yl)propyl]amines ( 13 ) and N‐arylsulfonyl‐N‐[3‐(1‐methyl‐1H‐imidazol‐2‐yl)propyl]amines ( 14 ) were prepared from the reaction of 3‐(1‐methyl‐1H‐imidazol‐2‐yl)propan‐1‐amine ( 7 ) with substituted benzoyl chloride or substituted‐benzene sulfonyl chloride respectively. Compound 7 was prepared by two independent methods. 相似文献
17.
W. B. Kang Seiko Nan'ya Etur
Maekawa Yoshio Ueno 《Journal of heterocyclic chemistry》1988,25(1):113-117
The acid-catalysed reaction of substituted 1,4-naphthoquinones with o-aminoheterocyclic thiones in alcoholic solution afforded substituted monoazabenzo[a]phenothiazin-5-ones 4,5 and substituted benzo[a][1,4]diazabenzothiazino[3,2-c]phenothiazin-5-one ( 6 ). Some of the resulting compounds were subjected to dehalogenation. The structures of the products were assigned by elemental analysis, 1H-nmr, and other spectral analysis. 相似文献
18.
Importance of a Fluorine Substituent for the Preparation of meta‐ and para‐Pentafluoro‐λ6‐sulfanyl‐Substituted Pyridines
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Dr. Mikhail Kosobokov Benqiang Cui Dr. Andrii Balia Kohei Matsuzaki Etsuko Tokunaga Norimichi Saito Prof. Dr. Norio Shibata 《Angewandte Chemie (International ed. in English)》2016,55(36):10781-10785
Although there are ways to synthesize ortho‐pentafluoro‐λ6‐sulfanyl (SF5) pyridines, meta‐ and para‐SF5‐substituted pyridines are rare. We disclose herein a general route for their synthesis. The fundamental synthetic approach is the same as reported methods for ortho‐SF5‐substituted pyridines and SF5‐substituted arenes, that is, oxidative chlorotetrafluorination of the corresponding disulfides to give pyridylsulfur chlorotetrafluorides (SF4Cl‐pyridines), followed by chloride/fluoride exchange with fluorides. However, the trick in this case is the presence on the pyridine ring of at least one fluorine atom, which is essential for the successful transformation of the disulfides into m‐and p‐SF5‐pyridines. After enabling the synthesis of an SF5‐substituted pyridine, ortho‐F groups can be efficiently substituted by C, N, S, and O nucleophiles through an SNAr pathway. This methodology provides access to a variety of previously unavailable SF5‐substituted pyridine building blocks. 相似文献
19.
《Journal of heterocyclic chemistry》2018,55(2):492-497
Polyhydroxy steroids bearing the 3β,5α,6β‐trihydroxy pattern were synthesized from different heterocyclic‐substituted unsaturated steroid by an easy and simple method with high yields. The endocyclic double bond of thiophene‐substituted and quinoline‐substituted steroids were converted to the trans‐diaxial diol by the regioselective and stereoselective reactions with m‐chloroperoxybenzoic acid in the basic medium. 相似文献
20.
Hydrolysis of substituted cyclopropane amino acids was performed. Free and partially substituted Z and E isomers of cyclopropane analogs of aspartic and adipic acids were obtained. 相似文献