- A general regioselective synthesis of 2,4-diarylpyrimidines from 2-thiouracil through two orthogonal cross-coupling reactions
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A novel efficient synthesis of 2,4-diarylpyrimidines was developed based on phosphonium-mediated Suzuki coupling of 2-(methylsulfanyl)pyrimidin-4(3H)-one (at position 4) followed by the Liebeskind-Srogl cross-coupling (at position 2) under microwave irradiation. Georg Thieme Verlag Stuttgart · New York.
- ?erňová, Miroslava,Pohl, Radek,Klepetá?ová, Blanka,Hocek, Michal
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supporting information; experimental part
p. 1305 - 1308
(2012/06/30)
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- Pyrimidine-core extended π-systems: General synthesis and interesting fluorescent properties
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We have developed a simple but powerful synthetic strategy that permits the assembly of π-systems onto a pyrimidine core in a programmable and diversity-oriented format. The nucleophilic addition of ArLi to 2-methylthiopyrimidine, followed by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) oxidation, resulted in the production of 4-aryl-2-methylthiopyrimidines. The iterative reaction sequence then gave 4,6-diaryl-2-methylthiopyrimidines. The resulting adduct was further allowed to react with ArMgBr under the catalytic influence of NiCl2(dppe) to afford 2,4,6-triarylpyrimidines. By following this synthetic scheme, interesting pyrimidine-core π-systems were rapidly constructed in a programmable fashion. The successful discovery of a number of interesting fluorescent materials and properties (e.g., solvatofluorochromism) speaks well for the potential of our platform strategy in the development of functional organic materials. Copyright
- Itami, Kenichiro,Yamazaki, Daisuke,Yoshida, Jun-Ichi
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p. 15396 - 15397
(2007/10/03)
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- Iron catalyzed cross coupling reactions of aromatic compounds
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A process for the production of compounds Ar—R1 by means of a cross-coupling reaction of an organometallic reagent R1—M with an aromatic or heteroaromatic substrate Ar—X catalyzed by one or several iron salts or iron complexes as catalysts or pre-catalysts, present homogeneously or heterogeneously in the reaction mixture. This new invention exhibits substantial advantages over established cross coupling methodology using palladium- or nickel complexes as the catalysts. Most notable aspects are the fact that (i) expensive and/or toxic nobel metal catalysts are replaced by cheap, stable, commercially available and toxicologically benign iron salts or iron complexes as the catalysts or pre-catalysts, (ii) commercially attractive aryl chlorides as well as various aryl sulfonates can be used as starting materials, (iii) the reaction can be performed under “ligand-free” conditons, and (iv) the reaction times are usually very short.
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Page/Page column 16
(2010/02/03)
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- Fungicides
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The invention provides fungicidal compounds of formula (I) or stereoisomers thereof: wherein X is CH2O; A is hydrogen; E is hydrogen; q is 1; any two of K, L and M are nitrogen and the other is CH; T is oxygen or sulfur; and Z is an optionally substituted phenyl group or an optionally substituted heterocyclyl group.
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- Iron-catalyzed cross-coupling reactions
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Simple iron salts such as FeCln, Fe(acac)n (n = 2,3) or the salen complex 4 turned out to be highly efficient, cheap, toxicologically benign, and environmentally friendly precatalysts for a host of cross-coupling reactions of alkyl o
- Fuerstner, Alois,Leitner, Andreas,Mendez, Maria,Krause, Helga
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p. 13856 - 13863
(2007/10/03)
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- Synthesis, antiviral (HSV-1) and antimycotic activities of ethyl or methyl 2,4-disubstituted 5-pyrimidinecarboxylates, 2,4-disubstituted 5-pyrimidinecarboxylic acids and 2,4-disubstituted pyrimidines
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The synthesis of ethyl or methyl 4-substituted or unsubstituted 2-methylthio-5-pyrimidinecarboxylates 3 a-i and 8 o mainly by reaction of ethyl or methyl 2-dimethylaminomethylene-3-oxoalkanoates with 2-methylisothiourea is described. Also some ethyl 2-sub
- Sansebastiano,Mosti,Menozzi,Schenone,Muratore,Petta,Debbia,Pesce Schito,Schito
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p. 335 - 355
(2007/10/02)
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- STANNYLATION REACTIONS AND CROSS-COUPLINGS IN PYRIMIDINES
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Pyrimidines have been stannylated in the activated 4-position by thermal decarboxylation of the corresponding carboxylic organotin esters.The decarboxylation can be catalyzed by bis(acetonitrile)palladium(II) dichloride. 4-Iodopyrimidines are 4-stannylate
- Majeed, Amera J.,Antonsen, Oyvind,Benneche, Tore,Undheim, Kjell
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p. 993 - 1006
(2007/10/02)
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- Regiochemistry in Pd-Catalysed Organotin Reactions with Halopyrimidines
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Chlorines in activated pyrimidine position is replaced by carbon substituents in Pd-catalysed reactions with organotin compounds.The 4(6)-position is more reactive than the 2-position allowing for regioselective coupling in 2,4(6)-dihalopyrimidines.A bromine substituent is required for coupling in the benzenoid 5-position.In 5-bromo-2,4-dichloropyrimidine the 4-chlorine is replaced before the 5-bromine and the latter before the 2-chloro substituent, all in a regioselective manner.The methodology can be used to introduce functionalized carbon substituents into any pyrimidine position.
- Solberg, Jan,Undheim, Kjell
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- REACTIONS OF HETEROCYCLIC CATIONS WITH N-CONTAINING NUCLEOPHILES. 14. RECYCLIZATION OF 2,6-DIPHENYLPYRYLIUM PERCHLORATE UNDER THE INFLUENCE OF NUCLEOPHILES WITH AN N-C-N FRAGMENT
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The recyclization of 2,6-diphenylpyrylium perchlorate under the influence of isothioureas, guanidine, 2-aminobenzimidazoles, 2-aminonaphthimidazole, 2-aminothiazole, 2-aminobenzothiazole, and 2-aminopyridine was studied.The examined reactions lead to monocyclic or condensed pyrimidines.
- Zvezdina, E. A.,Zhdanova, M. P.,Giryavenko, I. I.
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p. 714 - 719
(2007/10/02)
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- (Substituted-phenyl)-1,2,4-triazolo[4,3-a]-pyrimidines and (substituted-phenyl)-1,2,4-triazolo[1,5-a]pyrimidines
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This disclosure describes substituted 1,2,4-triazolo[1,5-a]pyrimidines and substituted 1,2,4-triazolo[4,3-a]pyrimidines which possess anxiolytic activity.
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