- Stereochemical modulation of emission behaviour in E/Z isomers of diphenyldipyrroethene from aggregation induced emission to crystallization induced emission
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Herein, we report the synthesis, separation and characterisation of the E- and Z-isomers of dipyrrolyldiphenylethene to study their emission behaviour in the aggregation state and solid state. The E-isomer showed pronounced aggregation induced emission (A
- Garg,Ganapathi,Rajakannu,Ravikanth
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Read Online
- Synthesis method of 2-aromatic acyl pyrrole compounds
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The invention relates to the field of organic synthesis, and discloses a synthesis method of 2-aromatic acyl pyrrole compounds, wherein the synthesis method comprises the steps: taking an N-aromatic acyl pyrrole compound as a raw material, and carrying ou
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Paragraph 0025-0028
(2021/06/12)
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- K2S2O8mediated synthesis of 5-Aryldipyrromethanes and meso-substituted A4-Tetraarylporphyrins
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The synthesis of dipyrromethanes from pyrrole and arylglyoxylic acids in the presence of K2S2O8at 90 C is reported affording dipyrromethanes in very good yields. Unlike an excess pyrrole traditionally used in dipyrromethane synthesis, the current method uses a stoichiometric amount of pyrrole avoiding any use of Br?nsted or Lewis acid. A gram scale synthesis of 5-phenyldipyrromethane is also achieved demonstrating potential scale up of dipyrromethanes using this method feasible. Subsequently, dipyrromethanes were converted to A4tetraarylporphyrins also in the presence of K2S2O8at 90C. A direct synthesis of A4-tetraphenylporphyrin from excess pyrrole and phenylglyoxylic acid in the presence of K2S2O8 at 90C is also reported.
- Laha, Joydev K.,Hunjan, Mandeep Kaur
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p. 664 - 673
(2021/06/03)
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- K2S2O8activation by glucose at room temperature for the synthesis and functionalization of heterocycles in water
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While persulfate activation at room temperature using glucose has primarily been focused on kinetic studies of the sulfate radical anion, the utilization of this protocol in organic synthesis is rarely demonstrated. We reinvestigated selected K2S2O8-mediated known organic reactions that invariably require higher temperatures and an organic solvent. A diverse, mild functionalization and synthesis of heterocycles using the inexpensive oxidant K2S2O8 in water at room temperature is reported, demonstrating the sustainability and broad scope of the method. Unlike traditional methods used for persulfate activation, the current method uses naturally abundant glucose as a K2S2O8 activator, avoiding the use of higher temperature, UV light, transition metals or bases.
- Hunjan, Mandeep Kaur,Laha, Joydev K.
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supporting information
p. 8437 - 8440
(2021/09/02)
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- Rational design of fluorescent probes for targeted: In vivo nitroreductase visualization
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Nitroreductase (NTR) has been recognized as a biomarker for identifying the hypoxic status of cancers. Therefore, it is of high scientific interest to design effective fluorescent probes for tracking NTR activity. However, studies on elucidation of the structure-performance relationship of fluorescent probes and those providing valuable insight into optimized probe design have rarely been reported. Three BODIPY based fluorescent probes were made by conjugation of para-, ortho-, and meta-nitrobenzene to the BODIPY core via a thiolether bond, respectively. Our study revealed that the linkage and nitro substituent position significantly influence the capability of nitroreductase detection.
- Chen, Ji-An,Gao, Jie,Gu, Xianfeng,Li, Mimi,Tan, Jiahui,Yin, Xiaofan,Zhao, Zhen
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supporting information
p. 4744 - 4747
(2020/07/13)
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- Selective PdII-Catalyzed Acylation of Pyrrole with Aldehydes. Application to the Synthesis of Celastramycin Analogues and Tolmetin
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The PdII-catalyzed C-2 acylation of pyrrole with aldehydes in the presence of TBHP as oxidant has been studied for the synthesis of di(hetero)aryl ketones. The use of 2-pyrimidine as directing group leads to 2-acylpyrroles in moderate to good yields, although 2,5-diacylpyrroles are obtained as by products. This side-reaction could be avoided using 3-methy-2-pyridine as directing group, obtaining selectively 2-acylpyrroles. The reaction has been extended to a series of aromatic and heteroaromatic aldehydes, obtaining the best results with electron rich aromatic aldehydes. The methodology has been applied in the synthesis of pyrrolomycin alkaloid Celastramycin analogues and for an improved synthesis of Tolmetin, a nonsteroidal anti-inflammatory drug.
- Santiago, Carlos,Rubio, Ibon,Sotomayor, Nuria,Lete, Esther
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p. 4284 - 4295
(2020/05/25)
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- Aroylation of Electron-Rich Pyrroles under Minisci Reaction Conditions
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The development of Minisci acylation on electron-rich pyrroles under silver-free neutral conditions has been reported featuring the regioselective monoacylation of (NH)-free pyrroles. Unlike conventional Minisci conditions, the avoidance of any acid that could result in the polymerization of pyrroles was the key to success. The umpolung reactivity of the nucleophilic acyl radical, generated in situ from arylglyoxylic acid, could help explain the mechanism of product formation with electron-rich pyrroles. Alternatively, the nucleophilic substitution of the acyl radical on the electron-deficient pyrrole radical cation is proposed.
- Laha, Joydev K.,Kaur Hunjan, Mandeep,Hegde, Shalakha,Gupta, Anjali
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supporting information
p. 1442 - 1447
(2020/02/22)
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- Design of fluorescent probes with optimized responsiveness and selectivity to GSH
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We designed and synthesized a series of BODIPY based probes with fast and distinct ratiometric responsiveness for discriminative detection of GSH from Cys and Hcy. The discriminative detection is based on the different products obtained by the SNAr between probes and thiol-containing amino acids. The amino group of the obtained thioether from the reaction with Cys or Hcy but not GSH would trigger an intramolecular nucleophilic substitution through five- or six-membered cyclic transition state, finally yielding an amino substituted derivative. To achieve highly discriminative detection and fast response, a series of structure modifications and improvements have been made by elongating the π-conjugation and introducing electron withdrawing groups, finally affording probe BOD-DBNPF with optimized responsiveness and selectivity. Importantly, BOD-DBNPF was successfully used for the selective detection of GSH from Cys with distinct fluorescent ratiometric responses in living HeLa cells.
- Chen, Ji-An,Zhang, Zhen-Yu,Gao, Jie,Tan, Jia-Hui,Gu, Xian-Feng
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supporting information
p. 1226 - 1230
(2019/03/27)
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- The Sn(IV)-tetra(4-sulfonatophenyl) porphyrin complexes with antioxidants: Synthesis, structure, properties
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Complexes of Sn(IV)-tetra(4-sulfophenyl)porphyrin with antioxidants (methoxydol and ionol) and their precursors (para-cresol and 3-hydroxypyridine) were synthesized. All four complexes were obtained by boiling in aqueous solutions of the p-sulfo substitut
- Mamardashvili, Galina M.,Lazovskiy, Dmitriy A.,Maltceva, Olga V.,Zh. Mamardashvili, Nugzar,Koifman, Oscar I.
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supporting information
p. 468 - 475
(2018/11/23)
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- Zinc mediated straightforward access to diacylpyrroles
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In this article, we report the preparation of various 2,4- and 2,5-diacylpyrroles via two zinc-mediated acylation reactions of non-protected pyrroles.
- Faye, Djiby,Mbaye, Mbaye Diagne,Coufourier, Sébastien,Lator, Alexis,Dieng, Samba Yandé,Gaillard, Sylvain,Renaud, Jean-Luc
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p. 492 - 499
(2017/05/19)
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- Palladium(II) Catalyzed C-H Functionalization Cascades for the Diastereoselective Synthesis of Polyheterocycles
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C-H activation offers huge potential in the generation of complex structures from simple starting materials. Herein we report the development of a highly diastereoselective palladium(II) catalyzed C-H functionalization cascade to produce novel, unsaturate
- Watt, Michael S.,Booker-Milburn, Kevin I.
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supporting information
p. 5716 - 5719
(2016/11/17)
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- Hexafluoro-2-propanol-Promoted Intermolecular Friedel-Crafts Acylation Reaction
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The intermolecular Friedel-Crafts acylation was carried out in hexafluoro-2-propanol to yield aryl and heteroaryl ketones at room temperature without any additional reagents.
- Vekariya, Rakesh H.,Aubé, Jeffrey
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supporting information
p. 3534 - 3537
(2016/08/16)
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- Design, synthesis and anxiolytic-like activity of 1-arylpyrrolo[1,2-a]pyrazine-3-carboxamides
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Abstract A series of 1-arylpyrrolo[1,2-a]pyrazine-3-carboxamides were designed and synthesized as 18 kDa translocator protein (TSPO) ligands. Anxiolytic-like activity of compounds was evaluated in the open field test and elevated plus maze test. Compounds 1a and 1b demonstrated high anxiolytic-like effect in the dose range of 0.1-1.0 mg/kg comparable with that of diazepam. The involvement of TSPO receptor in the mechanism of anxiolytic-like activity of new compounds was proved by antagonism of the most active compound 1a with TSPO selective inhibitor PK11195. In vitro binding studies demonstrated high TSPO affinities for compounds 1a and 1b.
- Mokrov,Deeva,Gudasheva,Yarkov,Yarkova,Seredenin
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p. 3368 - 3378
(2015/08/03)
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- Reactions of nitrilium salts with indole and pyrrole and their derivatives in the synthesis of imines, ketones and secondary amines
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Abstract Reactions of N-methyl- and N-ethyl-nitrilium salts with indole and pyrrole and their derivatives yield imines or imine salts in good yields. The related imines are obtained from the salts after careful basification and hydrolysis of the imine salts or the imines by heating with aqueous base give the related ketones in good yields. Alternatively, the imine salts can be reduced using sodium borohydride in methanol to give the related secondary amines.
- Giles, Robert G.,Heaney, Harry,Plater, M. John
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p. 7367 - 7385
(2015/08/24)
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- Synthesis of 2-benzoylpyrrole derivatives via C-H functionalization adjacent to nitrogen of pyrrole
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A direct transition-metal-free synthesis of 2-benzoylpyrrole derivatives from free (N-H) pyrroles and benzaldehyde has been developed. The benzoylation reaction at the 2 or 5-position of pyrrole proceeded well under the alkali metalation system and with 2
- Guo, Zhiqiang,Wei, Xuehong,Hua, Yupeng,Chao, Jianbin,Liu, Diansheng
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p. 3919 - 3922
(2015/06/08)
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- Synthesis of a new compound family, 1-aryl-3H-pyrrolo[2,1-d][1,2,5] triazepin-4(5H)-ones
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Representatives of a new family, 1-aryl-3H-pyrrolo[2,1-d][1,2,5]triazepin- 4(5H)-ones have been synthesized at our laboratory as bioisosters of biologically active 1-aryl-2,3-benzodiazepine-4-ones. The efficient synthetic route described applies the synth
- Milen, Mátyás,ábrányi-Balogh, Péter,Dancsó, András,Simig, Gyula,Volk, Balázs
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p. 465 - 476
(2014/01/06)
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- Facile Synthesis of 9,10,19,20-Tetraarylporphycenes
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A simple route was developed for the synthesis of 9,10,19,20-tetraarylporphycenes by combining both McMurry and oxidative synthetic strategies and using readily available precursors. The desired 5,6-diaryldipyrroethenes, which were prepared in multigram quantities over two steps, were used to prepare 9,10,19,20-tetraarylporphycenes under mild acid-catalyzed conditions. As 5,6-diaryldipyrroethene precursors can easily be prepared in multigram quantities, this method is useful for the preparation of meso-tetrarylporphycenes that contain different aryl substituents. The molecular structures of these macrocycles were determined by HRMS analysis as well as 1D and 2D NMR studies. The tetraarylporphycenes exhibited a strong Soret band at approximately 380 nm and three Q bands in the region of 580-655 nm. The tetraarylprophycenes are reasonably fluorescent and stable under redox conditions. A simple, rapid method was developed for the synthesis of meso-tetraarylporphycenes by employing a McMurry coupling followed by an oxidation reaction as the key steps. This synthetic strategy uses readily available precursors to afford 9,10,19,20-tetraarylporphycenes. The absorption, fluorescence, and electrochemical properties of these macrocycles were also studied.
- Ganapathi, Emandi,Chatterjee, Tamal,Ravikanth, Mangalampalli
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p. 6701 - 6706
(2016/02/18)
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- Acylation of pyrroles and their free (N-H)-derivatives via palladium-catalyzed carbopalladation of nitriles
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An efficient regioselective synthesis of 2-acylpyrroles via palladium-catalyzed addition of pyrroles with benzonitriles and subsequent hydrolysis is developed. The direct acylation reaction of protected as well as (NH)-free pyrroles proceeded smoothly to
- Jafarpour, Farnaz,Hazrati, Hamideh,Darvishmolla, Masoumeh
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supporting information
p. 3784 - 3788
(2015/02/19)
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- One-pot synthesis of 2,5-dihydropyrroles from terminal alkynes, azides, and propargylic alcohols by relay actions of copper, rhodium, and gold
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Relay actions of copper, rhodium, and gold formulate a one-pot multistep pathway, which directly gives 2,5-dihydropyrroles starting from terminal alkynes, sulfonyl azides, and propargylic alcohols. Initially, copper-catalyzed 1,3-dipolar cycloaddition of
- Miura, Tomoya,Tanaka, Takamasa,Matsumoto, Kohei,Murakami, Masahiro
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p. 16078 - 16082
(2015/01/09)
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- Solvent free synthesis of 2-acylpyrroles and its derivatives catalysed by reuseable zinc oxide
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A highly efficient procedure for preparing 2-acylpyrroles and its derivatives is described. The products were obtained through regioselective Friedel-Crafts reactions of pyrroles and its derivatives with alkyl or aryl acid chlorides catalysed by zinc oxide under solvent-free conditions. This method has the advantages of green chemistry, operational simplicity, solvent-free conditions, and recoverable catalyst.
- Zhang, Shuguang,Feng, Chengliang,Cai, Jin,Chen, Junqing,Hu, Huayou,Ji, Min
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p. 480 - 482
(2013/09/12)
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- Synthesis and in vitro antitumor activity of 1-(3-dimethylamino)propyl indolin-2-one derivatives
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A series of 1-(3-dimethylaminopropyl)indolin-2-one derivatives were designed and synthesized based on the structural features of TMP-20, LK-B030, and BX-517. These newly synthesized derivatives were evaluated for in vitro activity against five human cancer cell lines and three HUVECs. Results revealed that all of the target compounds 1a-h generally show potent activity against these cancer cell lines and higher selectivity on VEGF- and bFGF-stimulated HUVECs than HUVEC. In particular, 1f (IC50s: 1.10-1.47 μM) is 1.8-6.0-fold more potent than sunitinib against MDA-MB-231, A549, HL-60 and K-562, and 1.6-2.8-fold more potent than LK-B030 against MDA-MB-231 and A549.
- Lv, Kai,Wang, Li-Li,Zhou, Xin-Bo,Liu, Ming-Liang,Liu, Hong-Ying,Zheng, Zhi-Bing,Li, Song
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p. 1723 - 1729
(2013/07/26)
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- Design and synthesis of pyrrolotriazepine derivatives: An experimental and computational study
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The pyrrole derivatives having carbonyl groups at the C-2 position were converted to N-propargyl pyrroles. The reaction of those compounds with hydrazine monohydrate resulted in the formation of 5H-pyrrolo[2,1-d][1,2,5] triazepine derivatives. The synthesis of these compounds was accomplished in three steps starting from pyrrole. On the other hand, attempted cyclization of a pyrrole ester substituted with a propargyl group at the nitrogen atom gave, unexpectedly, the six-membered cyclization product, 2-amino-3-methylpyrrolo[1,2- a]pyrazin-1(2H)-one as the major product. The expected cyclization product with a seven-membered ring, 4-methyl-2,3-dihydro-1H-pyrrolo[2,1-d][1,2,5]triazepin-1- one was formed as the minor product and was converted quantitatively to the major product. The formation mechanism of the products was investigated, and the results obtained were also supported by theoretical calculations.
- Menges, Nurettin,Sari, Ozlem,Abdullayev, Yusif,Erdem, Safiye Sag,Balci, Metin
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p. 5184 - 5195
(2013/07/25)
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- Silver(I)-Catalyzed conia-ene reaction: Synthesis of 3-pyrrolines via a 5-endo-dig cyclization
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A novel method has been developed for the synthesis of 3-pyrrolines from β-ketopropargylamines via a 5-endo-dig carbocyclization. This transformation involves a silver-catalyzed Conia-ene type reaction tolerating broad substrate scope with good to excellent yields. Furthermore, this methodology has been extended for the construction of 2-substituted pyrroles under base-mediated conditions. Copyright
- Boominathan, Siva Senthil Kumar,Hu, Wan-Ping,Senadi, Gopal Chandru,Wang, Jeh-Jeng
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p. 3570 - 3574
(2014/01/06)
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- Friedel-crafts acylation of arenes with carboxylic acids using polystyrene-supported aluminum triflate
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Cross-linked polystyrene-supported aluminum triflate (Ps-Al(OTf) 3) has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for the acylation of aromatic compounds. The catalyst can be easily prepared from cheap starting materials, is stable (as a bench top catalyst) and is reusable.
- Boroujeni, Kaveh Parvanak,Parvanak, Kamran
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experimental part
p. 155 - 163
(2012/01/02)
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- Polystyrene supported Al(OTf)3: An environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of aromatic compounds
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Stable and non-hygroscopic polystyrene supported aluminium triflate (Ps-Al(OTf)3), which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of arenes using acid chlorides in the absence of solvent under mild reaction conditions. The catalyst can be reused up to five times after simple washing with dichloromethane.
- Boroujeni, Kaveh Parvanak
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experimental part
p. 3156 - 3158
(2012/05/20)
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- A novel one-pot synthesis of 2-benzoylpyrroles from benzaldehydes
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We herein report a novel one-pot reaction for benzoylation of pyrrole. The key step in the reaction is generation of di(1H-pyrrol-1-yl)zirconium(IV) chloride complex which reacts with benzaldehydes and methyl benzoates to give 2-benzoylpyrroles as the major product.
- Sharma, Ratnesh,Chouhan, Mangilal,Nair, Vipin A.
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experimental part
p. 2039 - 2043
(2010/06/14)
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- Friedel-Crafts acylation of arenes with carboxylic acids using silica gel supported AlCl3
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Aromatic compounds react smoothly with carboxylic acids in the presence of silica gel supported aluminium trichloride to afford the corresponding ketones with high regioselectivity in high to excellent yields. The catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency. tuebitak.
- Parvanak Boroujeni, Kaveh
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experimental part
p. 621 - 630
(2010/11/04)
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- In Situ vinylpyrrole synthesis. Diels-alder reactions with maleimides to give tetrahydroindoles
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(Chemical Equation Presented) A series of 108 tetrahydroindoles has been prepared by a one-pot synthesis from 2-alkylpyrroles, cyclic ketones, maleimides, and an acid catalyst. A 5-vinylpyrrole is formed by an acid-catalyzed condensation of a 2-alkyl-substituted pyrrole with a ketone, which is subsequently trapped in situ by a maleimide in a predominantly endo-addition Diels-Alder reaction. Isomerization of the double bond into the pyrrole ring gives a tetrahydroindole with predominant cis-fusion of the cycloalkane ring.
- Noland, Wayland E.,Lanzatella, Nicholas P.,Sizova, Elena P.,Venkatraman, Lakshmanan,Afanasyev, Oleg V.
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scheme or table
p. 503 - 534
(2009/09/05)
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- HETEROCYCLIC MODULATORS OF TGR5
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The present invention relates to heterocyclic compounds useful as modulators of TGR5 and methods for the treatment of prevention of metabolic, cardiovascular, and inflammatory diseases.
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Page/Page column 64
(2008/12/06)
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- Vilsmeier-Haack preparation of 2-acylpyrroles using bis(trichloromethyl) carbonate and N,N-dimethylacylamines
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A series of 2-acylpyrroles were synthesized by using bis(trichloromethyl) carbonate and N,N-dimethylacylamines as Vilsmeier-Haack reagents under mild conditions in good yields.
- Shi,Su,Shan
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p. 1019 - 1021
(2007/10/03)
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- Aluminum dodecatungstophosphate (AlPW12O40) as a non-hygroscopic Lewis acid catalyst for the efficient Friedel-Crafts acylation of aromatic compounds under solvent-less conditions
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Stable and non-hygroscopic aluminum dodecatungstophosphate (AlPW 12O40), which is prepared easily from cheap and commercially available compounds was found to be an effective catalyst for Friedel-Crafts acylation reactions using carboxylic acids, acetic anhydride and benzoyl chloride in the absence of solvent under mild reaction conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad
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p. 10843 - 10850
(2007/10/03)
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- Infrared and Nuclear Magnetic Resonance Properties of Benzoyl Derivatives of Five-membered Monoheterocycles and Determination of Aromaticity Indices
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Benzophenones, 2-benzoylthiophenes, 2-benzoylpyrroles, and 2-benzoylfurans, which have substituents at m- and p-positions of the benzoyl ring were prepared and their ir and nmr spectra were obtained in 0.1 M chloroform-d solution. The chemical shift values of each series were plotted against the Hammett substituent parameters to give good correlation, with the exception of the ortho-Hs and -Cs. The slopes as well as the differences in chemical shift gave sets of meaningful values for the indices of aromaticy.
- Jeon, Kyu Ok,Jun, Jung Ho,Yu, Ji Sook,Lee, Chang Kiu
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p. 763 - 771
(2007/10/03)
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- Diethoxymethyl protected pyrroles: Synthesis and regioselective transformations
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Treatment of the acceptor-substituted pyrroles 1a-k with neat triethyl orthoformate gives access to the diethoxymethyl (DEM) protected derivatives 2a-k in high yield. Convenient and mild cleavage was achieved by subsequent treatment of the DEM-pyrroles 2a-k with trifluoroacetic acid in acetonitrile and aqueous NaOH at room temperature. DEM protection proved suitable for a variety of regioselective transformations involving directed orthometalation and iodine-magnesium exchange processes. Furthermore, electrophilic halogenations and Pd-catalyzed coupling reactions were also carried out.
- Bergauer,Gmeiner
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p. 2281 - 2288
(2007/10/03)
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- Synthesis of some diethylphosphono substituted 3H-pyrrolizines
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The preparation of various alkyl substituted monophosphonate 3H-pynolizines via a tandem Michael □ Horner-Emmons reaction is reported. These products were prepared from tetraethyl ethylidene gem-bisphosphonate and corresponding 2-acylpyrroles.
- Loussouarn,Servant,Guervenou,Sturtz
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p. 275 - 285
(2007/10/03)
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- One-flask synthesis of meso-substituted dipyrromethanes and their application of the synthesis of trans-substituted porphyrin building blocks
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The reaction at room temperature of an aldehyde with excess pyrrole in the absence of solvent affords the meso-substituted dipyrromethane. The reaction is catalyzed with trifluoroacetic acid or with BF3·O(Et)2. The dipyrromethane is purified by crystallization or by flash chromatography on silica with eluants containing 1% triethylamine. The reaction is compatible with aliphatic or aromatic aldehydes, including 2,6-disubstituted benzaldehydes. Nine dipyrromethanes have been prepared in this manner in yields of 47-86%, indicating the broad scope of the reaction. The dipyrromethanes are stable in the purified form in the absence of light and air. Similar reaction with terephthalaldehyde and pyrrole affords the corresponding bis-dipyrromethane. The reaction of a meso-substituted dipyrromethane with an aldehyde under the conditions of the two-step one-flask porphyrin synthesis affords a direct route to trans-substituted meso-porphyrins. Acidolysis of the dipyrromethane is negligible under the conditions of the porphyrin-forming reaction. Four porphyrins bearing peripheral functional groups and facially-encumbering groups have been prepared which serve as key building blocks in the synthesis of linear porphyrin arrays.
- Lee,Lindsey
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p. 11427 - 11440
(2007/10/02)
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- General Methods for Synthesizing 2,4-Diacylpyrroles and their Precursors Containing One or Two Masked Acyl Groups
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A thorough study of the synthesis of 2,4-diacylpyrroles by direct acylation of pyrrole and 2- and 3-acylpyrroles is reported.Among these, Friedel-Crafts acylation of 3-acylpyrroles is the most general and advantageous method because it utilises easily accessible starting materials.In addition it is always regiospecific and readily provides 2,4-diacylpyrroles containing identical or different acyl groups in very high yields (81-100percent) under mild conditions, Alternative procedures concern the synthesis of precursors of 2,4-diacylpyrroles containing one or two acyl groups masked by a 1,3-benzodithiolyl or 1,3-benzoxathiolyl group and subsequent hydrolysis with HgO-35percent aq.HBF4-Me2SO.Overall yields are always good (52-60percent).Indirect acylation constitutes a secure complement to direct acylation when it is necessary to operate in the presence of protected acyl groups.
- Cadamuro, Silvano,Degani, Iacopo,Dughera, Stefano,Fochi, Rita,Gatti, Antonella,Piscopo, Laura
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p. 273 - 284
(2007/10/02)
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- Rational Tetraarylporphyrin Syntheses: Tetraarylporphyrins from the MacDonald Route
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Four new synthetic routes to meso-tetraarylporphyrins using a MacDonald-type 2 + 2 condensation are described.Self-condensation of a 5-arylpyrromethane (e.g., 17) with an aryl-substituted one-carbon bridging unit affords a mixture of tetraarylporphyrins due to acid-catalyzed redistribution reactions.The second and third methods presented here show wide applicability for the preparation of 5,10,15,20-tetraaryl-substituted porphyrins (e.g., 31, 37, 48, 49) with 2-fold rotational symmetry and involve self-condensation of 5-aryl-1-aryldipyrromethanecarbinols.Finally, the fourth approach involves a 2 + 2 approach in which one of the two dipyrromethanes bears both of the bridging carbons in the porphyrin products, affording porphyrin 50 which possesses three different aryl rings, with one pair of uniquely opposite identical aryl groups.The last two 2 + 2 methods are further extended to give a tetraarylporphyrin 38 bearing four different aryl groups in a predesignated array, the structure of which is confirmed by a single-crystal X-ray study.
- Wallace, David M.,Leung, Sam H.,Senge, Mathias O.,Smith, Kevin M.
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p. 7245 - 7257
(2007/10/02)
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- Antifungal agents, II: Synthesis and antifungal activities of aryl-1H-pyrrol-2-yl-1H-imidazol-1-yl-methane derivatives with unsaturated chains
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The synthesis and antifungal activities of aryl-1H-pyrrol-2-yl-1H-imidazol-1-yl-methanes having allyl, crotyl, and acrylate chains linked to the N-pyrrole atom and substituted at phenyl ring by Cl, F, CH3, and NO2 groups are reported
- Massa,Ragno,Porretta,Mai,Retico,Artico,Simonetti
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p. 539 - 546
(2007/10/02)
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- Ethenyl-substituted dipyrrometheneboron difluoride dyes and their synthesis
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This invention relates to ethenyl-substituted derivatives of dipyrrometheneboron difluoride dyes that have an absorption maximum at wavelengths longer than about 525 nm, and are electrically neutral, highly photostable and, in most cases, highly fluoresce
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- Process for preparing 5-aroyl-2,3-dihydro-1H-pyrrolizine-1,1-dicarboxylates (II) and intermediates therefor
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5-Aroyl-2,3-dihydro-1H-pyrrolizine-1,1-dicarboxylates of the formula STR1 are prepared from 2-aroylpyrroles. Hydrolysis and mono-decarboxylation of these compounds affords ketorolac and related compounds.
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- RECYCLIZATION OF PYRROLOPYRAZINIUM SALTS INTO 6- AND 8-AMINOINDOLIZINES
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Recyclization of 3-alkylpyrrolopyrazinium salts in the presence of base afforded derivatives of 6-aminoindolizine.Rearrangement of 1,3-dialkylpyrrolopyrazinium salts proceeded in two directions, giving rise to both 6- and 8-aminoindolizines,
- Terenin, V. I.,Kabanova, E. V.,Feoktistova, E. S.,Bundel', Yu. G.
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p. 766 - 771
(2007/10/02)
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- Gas-phase heteroaromatic substitution. 11. Electron transfer mechanism in the gas-phase acylation of simple five-membered heteroarenes
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The results of a study of the gas-phase reactions of unsaturated carbocations, such as the CH3CO+ ion from γ-radiolysis of CH3F/CO mixtures, and the C6H4TCO+ ion from the β-decay of 1,4-ditritiobenzene in the presence of CO, with pyrrole, N-methylpyrrole, furan, and thiophene, are reported.In all systems investigated, acylated heteroarenes represent the predominant reaction products, accompanied by the methylated derivatives in the CH3F/CO radiolytic mixtures, and by the phenylated ones in the 1,4-ditritiobenzene/CO decay samples.All substrates investigated are found to undergo predominat α substitution by both acetyl (88.6-98.4percent (pyrrole); 90.8-98.7percent (N-methylpyrrole); 97.2-98.9percent (furan); 94.9-98.6percent (thiophene)) and benzoyl cations (92.6-96.5percent (pyrrole)) under all conditions.The predominant formation of the α-acylated pyrroles from both reactants (>88percent), whose relative yields appear unaffected within the temperature interval from 303 to 383 K, indicates, in agreement with ancillary FT-ICR mass spectrometric evidence, that gas-phase acylation reactions toward simple five-membered heteroarenes proceed via a two-step substitution mechanism, involving a quasi-resonant single-electron transfer (SET) step followed by recombination of the ensuing radical - radical ion pair.By virtue of this entropy-favored mechanism, gaseous electrophiles with relatively high SCF STO-3G calculated LUMO energies such CH3CO+ and C6H4TCO+ are effectively oriented toward the "soft" Cα sites of the selected heteroarenes, at variance with Klopman's Charge and Frontier Orbital Control predictions.The behavior of gaseous acylating reactants toward simple heteroarenes is discussed and compared with that of other gaseous electrophiles, whose reactivity appears instead in qualitative agreement with Klopman's model.
- Filippi, Antonello,Occhiucci, Giorgio,Sparapani, Cinzia
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p. 740 - 748
(2007/10/02)
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- The N-tert-butylcarbamoyl directed metalation group for the regiospecific synthesis of 2-substituted pyrroles and indoles
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The N-tert-butylcarbamoyl serves as a useful, readily removable (LiOH/MeOH/THF) new directed metalation group for the synthesis of 2-substituted pyrroles and indoles.
- Gharpure,Stoller,Bellamy,Firnau,Snieckus
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p. 1079 - 1082
(2007/10/02)
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- 2-SUBSTITUTED 1,3-BENZODITHIOLIUM TETRAFLUOROBORATES AS USEFUL ACYLATING AGENTS OF PYRROLE
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A comparative study on the acylation of pyrrole by utilizing 2-substituted 1,3-benzodithiolium tetrafluoroborates instead of 2-substituted 1,3-benzoxathiolium tetrafluoroborates has been accomplished.The use of 2-substituted 1,3-benzodithiolium tetrafluoroborates proved to be more convenient since it gives higher yields of 2-acylpyrroles (58-90percent) and appears of larger applicability for the preparation of symmetrical and unsymmetrical 2,5-diacylpyrroles which were obtained in most cases in quantitative yields.
- Barbero, Margherita,Cadamuro, Silvano,Degani, Iacopo,Dughera, Stefano,Fochi, Rita,et al.
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p. 619 - 627
(2007/10/02)
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- SYNTHESE DE PYRROLES ET D'OXAZOLES PAR PYROLYSE DE N-(HYDROXY-2' ETHYL) AMINO-3 PROPENOATE
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The gas phas pyrolysis of various N-(2'-hydroxyethyl)-3-amino propenoates 1-6 and N-(2'-hydroxy-2'-phenyl ethyl)-3-amino propanoate 7-9 at 390 deg C-420 deg C leads respectively to formylpyrroles 11-16 and benzoylpyrroles 17-19 and, in some cases, to substituted oxazoles 36-39.The results are best explained by the intermediate formation of a dicarbonyl derivative followed either by an intramolecular thermal crotonisation or a six ? electrocyclization of an azomethine ylide.
- Pale-Grosdemange, Catherine,Chuche, Josselin
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p. 3397 - 3414
(2007/10/02)
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- First Reactions of Dialkoxycarbenium Tetrafluoroborates with Pyrroles, 5H-Dibenzazepines, and Electron-Rich Arenes
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Pyrrole (2a) and 2,5-dimethylpyrrole (2b) react with the dialkoxycarbenium tetrafluoroborates 1a-1c under kinetic control to yield the corresponding acylpyrrole derivatives. 5H-Dibenzazepine (9a) and the 10,11-dihydro derivative 9b react only with the most elecrophilic of the series of electrophiles tested, namely, diethoxycarbenium tetrafluoroborate (1a), to furnish the corresponding formyl derivatives.Similarly, in arene chemistry, the highly electron-rich N,N-dimethylaniline (13a) and 1,3,5-trimethoxybenzene (13b) are formylated by reaction with 1a.
- Pindur, U.,Flo, C.
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p. 1563 - 1568
(2007/10/02)
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- A NEW ROUTE FOR MESO-SUBSTITUTED PORPHYRIN
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A new synthetic route of meso-substituted porphyrins was esthablished.The method presented here shows wide applicability for the preparation of aryl and alkyl meso-substituted porphyrins.
- Kuroda, Yasuhisa,Murase, Hiroaki,Suzuki, Yasuhiko,Ogoshi, Hisanobu
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p. 2411 - 2412
(2007/10/02)
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- 2-Substituted 1,3-Benzoxathiolium Tetrafluoroborates as Useful Acylating Agents of Electron-Rich Aromatic and Heteroaromatic Compounds
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2-Substituted 1,3-benzoxathiolium tetrafluoroborates were used for the two-step acylation of electron-rich aromatic and heteroaromatic compounds: 1,3-dimethoxybenzene, 1,3,5-trimethoxybenzene, pyrrole and indoles.In most of the cases intermediate 2,2-disubstituted 1,3-benzoxathioles were obtained in good to high yields (55-100percent) and subsequent hydrolysis of these with mercury(II) oxide and aqueous tetrafluoroboric acid (35percent) in tetrahydrofuran afforded the corresponding ketones in almost quantitative yields.
- Cadamuro, Silvano,Degani, Iacopo,Fochi, Rita,Gatti, Antonella,Regondi, Valeria
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p. 311 - 314
(2007/10/02)
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- FRIEDEL-CRAFTS ACYLATION OF 1-TERT-BUTYLDIMETHYLSILYLPYRROLE, A VERY SHORT AND SIMPLE ROUTE TO 3-SUBSTITUTED PYRROLES.
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1-tert-Butyldimethylsilylpyrrole undergoes Friedel-Crafts acylation almost exclusively at β-position giving after sodium fluoride supported hydrolysis the 3-pyrroloketones.
- Simchen, Gerhard,Majchrzak, Michal W.
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p. 5035 - 5036
(2007/10/02)
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- THE FORMATION OF ACYLAMINO-DERIVATIVES OF INDOLES AND PYRROLES BY REACTIONS WITH NITRILIUM SALTS
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N-Methylnitrilum fluoroborates are prepared rapidly by warming trimethyloxonium fluoroborate wiht a slight excess of the nitrile, subsquent addition of indoles and pyrroles at low temperatures (-50 deg C to -20 deg C) gives iminium salts (and hence ketones) in high yields.
- Eyley, Stephen C.,Giles, Robert G.,Heaney, Harry
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p. 4649 - 4652
(2007/10/02)
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