25827-94-5Relevant academic research and scientific papers
Selective synthesis of oxazoles and pyrazines from α-bromo-1-phenylethanone using a by-product-promoted strategy
Liu, Changhui,Zhao, Jiateng,Qiao, Yu,Huang, Wenbo,Rao, Zhonghao,Gu, Yanlong
, p. 7351 - 7357 (2018/11/23)
Oxazoles and pyrazines are fundamental heterocycles that widely found in natural products or drugs. In this work, a selective strategy for oxazoles and pyrazines synthesis using α-bromo-1-phenylethanone and ammonium acetate as starting materials was reported. This methodology features mild reaction conditions, readily accessible starting materials and good chemoselectivity. Mechanistic study indicates that this reaction involves a by-product-promoted (BPP) process for the formation of oxazole, that is, the in-situ formed hydrogen bromide (HBr) during the reaction promotes the whole tandem process.
Acceptorless Dehydrogenative Coupling Using Ammonia: Direct Synthesis of N-Heteroaromatics from Diols Catalyzed by Ruthenium
Daw, Prosenjit,Ben-David, Yehoshoa,Milstein, David
supporting information, p. 11931 - 11934 (2018/09/27)
The synthesis of N-heteroaromatic compounds via an acceptorless dehydrogenative coupling process involving direct use of ammonia as the nitrogen source was explored. We report the synthesis of pyrazine derivatives from 1,2-diols and the synthesis of N-substituted pyrroles by a multicomponent dehydrogenative coupling of 1,4-diols and primary alcohols with ammonia. The acridine-based Ru-pincer complex 1 is an effective catalyst for these transformations, in which the acridine backbone is converted to an anionic dearomatized PNP-pincer ligand framework.
Switchable Synthesis of Pyrroles and Pyrazines via Rh(II)-Catalyzed Reaction of 1,2,3-Triazoles with Isoxazoles: Experimental and DFT Evidence for the 1,4-Diazahexatriene Intermediate
Rostovskii, Nikolai V.,Ruvinskaya, Julia O.,Novikov, Mikhail S.,Khlebnikov, Alexander F.,Smetanin, Ilia A.,Agafonova, Anastasiya V.
, p. 256 - 268 (2017/04/26)
4-Aminopyrrole-3-carboxylates and pyrazine-2-carboxylates were synthesized from 5-alkoxyisoxazoles and 1-sulfonyl-1,2,3-triazoles by tuning the Rh(II) catalyst and the reaction conditions. The reaction in chloroform at 100 °C under Rh2(OAc)4 catalysis provides 4-aminopyrrole-3-carboxylates in good yields. The use of Rh2(Piv)4 in refluxing toluene results in the formation of 1,2-dihydropyrazine-2-carboxylates as the main products, which can be converted by a one-pot procedure to pyrazine-2-carboxylates by heating with catalytic amounts of TsOH. According to the NMR and DFT investigations of the reaction mechanism, pyrroles and dihydropyrazines are formed, respectively, via 1,5- and 1,6-cyclization of common (5Z)-1,4-diazahexa-1,3,5-triene intermediates. The influence of the nature of the catalyst on the product distribution is rationalized in terms of the Rh-catalyzed isomerization of a pyrrolin-2-ylium-3-aminide zwitterion, the primary product of 1,4-diazahexatriene 1,5-cyclization.
The reaction of α-halocarbonyl compounds with (NH4)OH, (NH4)So4 or NH4CI solution under microwave-irradiation
Utsukihara, Takamitsu,Koshimura, Masahiro,Kitsuta, Kazunori,Sato, Akinori,Matsushita, Masatoshi,Takahashi, T. Tomoyoshi,Horiuchi, C. Akira
, p. 1495 - 1502 (2017/11/10)
Reaction of α-halo ketone (a-bromo ketone) under microwave, irradiation gives the pyrazine and quinoxaline derivative in good yields. This reaction affords a clean and convenient synthetic method for pyrazine and quinoxaline derivatives.
A general catalyst for Suzuki-Miyaura and Sonogashira reactions of aryl and heteroaryl chlorides in water
Peng, Hui,Chen, Ya-Qin,Mao, Shu-Lan,Pi, Yun-Xiao,Chen, You,Lian, Ze-Yu,Meng, Tong,Liu, Sheng-Hua,Yu, Guang-Ao
supporting information, p. 6944 - 6952 (2014/09/29)
We report the synthesis of 2-(3-sulfonatomesityl)-5-sulfonatoindenyl) dicyclohexylphosphine hydrate sodium salt and its use in palladium-catalyzed Suzuki-Miyaura and Sonogashira coupling reactions in water (and biphasic water-organic solvent mixtures) to prepare a variety of functionalized biaryls and aryl alkynes in excellent yield. This journal is the Partner Organisations 2014.
Highly efficient synthesis of 2,5-disubstituted pyrazines from (Z)-β-haloenol acetates
Chen, Zhengwang,Ye, Dongnai,Xu, Guohai,Ye, Min,Liu, Liangxian
, p. 6699 - 6702 (2013/10/01)
A highly efficient synthesis of a wide range of 2,5-disubstituted pyrazines from (Z)-β-haloenol acetates is described. The reactions are conducted under convenient conditions and provide products with excellent regioselectivity in moderate to excellent yields with a broad substrate scope, including a variety of aromatic and aliphatic haloenol acetates.
Synthesis of biaryls through a one-pot tandem borylation/Suzuki-Miyaura cross-coupling reaction catalyzed by a palladacycle
Wang, Lianhui,Cui, Xiuling,Li, Jingya,Wu, Yusheng,Zhu, Zhiwu,Wu, Yangjie
experimental part, p. 595 - 603 (2012/03/09)
The tricyclohexylphosphane adduct of cyclopalladated ferrocenylimine I exhibited high catalytic activity in the one-pot borylation/Suzuki-Miyaura coupling (BSC) reaction with low catalyst loading (2 mol-%). Various biaryls were obtained in good to excellent yields for 37 examples. This process was applied to aryl and heteroaryl halides (Br and Cl) containing a variety of functional groups and did not require an excess amount of phosphane ligand and the addition of the palladium catalyst in the second step. Cyclopalladated ferrocenylimine I exhibited high catalytic activity in the borylation/Suzuki- Miyaura coupling (BSC) reaction with low catalyst loading. Various unsymmetrical biaryls were obtained ingood to excellent yields in one pot. This protocol was applied to aryl and heteroaryl halides (Br and Cl) containing a variety of functional groups without adding catalyst in the second step. Copyright
The study of cyclization of N-acylphenacyl anthranilates with ammonium salts under various conditions
Hradil, Pavel,Grepl, Martin,Hlavac, Jan,Lycka, Antonin
, p. 269 - 280 (2008/02/09)
N-Acylphenacyl anthranilates were heated with ammonium salts in organic acid or NMP, and formation of various heterocyclic compounds was observed. Reaction results are strongly influenced by reaction conditions. The most interesting are imidazole derivati
Suzuki cross-couplings on aryl (heteroaryl) bromides and chlorides with bulky aliphatic phosphines/Pd(0)-triolefinic macrocyclic catalyst
Moreno-Ma?as, Marcial,Pleixats, Roser,Serra-Muns, Anna
, p. 3001 - 3004 (2008/02/12)
The combination of a bulky aliphatic phosphine, e.g. tricyclohexylphosphine or the tetrafluoroborate salt of tri-tert-butylphosphine, with the Pd(0) complex of a 15-membered triolefinic macrocycle is an excellent catalyst for the Suzuki cross-coupling of aryl and heteroaryl bromides and chlorides. The palladium can be recovered in the form of the initial complex. Georg Thieme Verlag Stuttgart.
NOVEL USE OF TRICYCLIC COMPOUND
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Page/Page column 14-15; 17, (2008/06/13)
Pharmaceutical compositions for enhancing the expression of apoAI are provided, which are used as medicaments for treatment of cardiovascular diseases on the basis of improving the functions of HDL.Pharmaceutical compositions for enhancing the expression of apoAI which comprises a compound of formula (I): in which X1 and X2 are independently an aryl or heteroaryl that may be optionally substituted, a hydrogen, a halogen, or the like; ring A is a benzene ring or 6-membered aromatic heterocyclic ring containing 1 to 3 N atoms that may be optionally condensed with another aromatic ring; R1 to R4 are independently a hydrogen, a halogen, a lower alkyl, a lower alkoxy or the like; a prodrug thereof, a pharmaceutically acceptable salt or solvate of them are disclosed.
