排序方式: 共有14条查询结果,搜索用时 62 毫秒
1.
Viktor O. Iaroshenko Verena SpecowiusKatharina Vlach Marcelo Vilches-HerreraDmytro Ostrovskyi Satenik MkrtchyanAlexander Villinger Peter Langer 《Tetrahedron》2011,67(31):5663-5677
Difluoromethyl-containing heteroannulated pyridines, pyrimidines and pyrazoles are prepared by a two step method. The regioselective cyclizations of electron-excessive aminoheterocycles, hydrazines and amidines with CF2Cl-substituted 1,3-dicarbonyl compounds provide the corresponding CF2Cl-substituted heterocycles. Subsequent radical reactions with trimethylstannane or allyltrimethylstannane gave difluoromethyl-containing heteroannulated pyridines, pyrimidines and pyrazoles, respectively. 相似文献
2.
Karapetyan V Mkrtchyan S Schmidt A Gütlein JP Villinger A Reinke H Jiao H Fischer C Langer P 《Organic & biomolecular chemistry》2008,6(16):2961-2968
A variety of functionalized 3,4-benzo-7-hydroxy-2,9-diazabicyclo[3.3.1]non-7-enes were prepared by one-pot cyclizations of 1,3-bis(silyl enol ethers) with quinazolines. The mechanism of the cyclization was studied by B3LYP/6-31G(d) density functional theory computations. The products could be functionalized by Suzuki cross-coupling reactions. The reaction of 1,3-bis(silyl enol ethers) with phthalazine afforded open-chain rather than cyclization products. 相似文献
3.
Viktor O. Iaroshenko Satenik Mkrtchyan Ashot Gevorgyan Marcelo Vilches-Herrera Dmitri V. Sevenard Alexander Villinger Tariel V. Ghochikyan Ashot Saghiyan Vyacheslav Ya. Sosnovskikh Peter Langer 《Tetrahedron》2012,68(11):2532-2543
3-Nitrochromone reacts with electron-rich aminoheterocycles (in glacial acetic acid at reflux) and anilines (in a mixture of DMF and TMSCl at 100–140 °C) to give a variety of hetero(carbo)annulated 3-nitropyridines. The reaction, involving a formal [3+3] cyclocondensation, proceeds in high yields and appears not to be influences greatly by the nature of the 1,3-C,N-dinucleophile as seen from the thorough scope study. The synthetic utility of the products was demonstrated by their conversion into the corresponding 3-aminopyridine derivatives. An NMR study and X-ray crystallographic analysis are reported. 相似文献
4.
Satenik Mkrtchyan Micha Jakubczyk Suneel Lanka Michael Pittelkow Viktor O. Iaroshenko 《Molecules (Basel, Switzerland)》2021,26(10)
We describe a mechanism-guided discovery of a synthetic methodology that enables the preparation of aromatic amides from 2-bromo-2,2-difluoroacetamides utilizing a copper-catalyzed direct arylation. Readily available and structurally simple aryl precursors such as aryl boronic acids, aryl trialkoxysilanes and dimethyl-aryl-sulfonium salts were used as the source for the aryl substituents. The scope of the reactions was tested, and the reactions were insensitive to the electronic nature of the aryl groups, as both electron-rich and electron-deficient aryls were successfully introduced. A wide range of 2-bromo-2,2-difluoroacetamides as either aliphatic or aromatic secondary or tertiary amides were also reactive under the developed conditions. The described synthetic protocols displayed excellent efficiency and were successfully utilized for the expeditious preparation of diverse aromatic amides in good-to-excellent yields. The reactions were scaled up to gram quantities. 相似文献
5.
Bagyan S Mair T Suchorski Y Hauser MJ Straube R 《The journal of physical chemistry. B》2008,112(45):14334-14341
The dynamics of glycolytic waves in a yeast extract have been investigated in an open spatial reactor. At low protein contents in the extract, we find a transition from inwardly moving target patterns at the beginning of the experiment to outwardly moving spiral- or circular-shaped waves at later stages. These two phases are separated by a transition phase of more complex spatiotemporal dynamics. We have analyzed the pattern dynamics in these three intervals at different spatial scales by means of a Karhunen-Loeve (KL) decomposition. During the initial phase of the experiment, the observed patterns are sufficiently described by the two dominant KL modes independently of the spatial scale. However, during the last stage of the experiment, at least 6 KL modes are needed to account for the observed patterns at spatial scales larger than 3 mm, while for smaller scales, 2 KL modes are still sufficient. This indicates that in the course of the experiment, the local glycolytic oscillators become desynchronized at spatial scales larger than 3 mm. Possible reasons for the desynchronization of the glycolytic waves are discussed. 相似文献
6.
6-Iodo- and 6-bromomethyl-5,6-dihydro-4H-1,2-oxazines were prepared by condensation of dilithiated acetophenone-oximes with allylbromide and subsequent regioselective iodine- or NBS-mediated cyclization. 相似文献
7.
Viktor O. Iaroshenko Sajid Ali Satenik Mkrtchyan Ashot Gevorgyan Tariq Mahmood Babar Volodymyr Semeniuchenko Zahid Hassan Alexander Villinger Peter Langer 《Tetrahedron letters》2012,53(52):7135-7139
A concise and efficient approach to a series of chromen-4-ones with fused thiophene ring has been developed using the Suzuki–Miyaura reaction of bromothiophene-2- and 3-carboxylates with 2-methoxyboronic acids and subsequent cyclization of prepared alkyl (2-methoxy)aryl thiophene-2- and 3-carboxylates under the action of BBr3/KOtBu. Starting bromothiophenes are easily obtained from corresponding commercially available aminothiophenes by diazotization/bromination reaction. 相似文献
8.
Ashot S. Saghyan Gnel M. Mkrtchyan Ani S. Dadayan Satenik G. Petrosyan Arpine V. Geolchanyan Hayarpi M. Simonyan Anna F. Mkrtchyan Satenik Mkrtchyan Ashot Gevorgyan Viktor O. Iaroshenko Peter Langer 《Tetrahedron: Asymmetry》2013,24(4):229-232
The conjugate addition of S-, N- and O-heterocyclic nucleophiles to the CC bond of dehydroalanine, bonded as a Schiff’s base to the chiral auxiliary (S)-2-[N-(N′-benzylprolyl)amino]benzophenone in the coordination sphere of NiII, resulted in the asymmetric synthesis of novel (S)-α-aminopropionic acids containing a heterocyclic side chain, including imidazole, triazole, thiodiazole, thiazole and oxazole moieties (de 20–92%). After purification and cleavage of the metal complexes, the heterocyclic amino acids were isolated with high enantiomeric purity (ee >97%). 相似文献
9.
Iaroshenko VO Mkrtchyan S Gevorgyan A Miliutina M Villinger A Volochnyuk D Sosnovskikh VY Langer P 《Organic & biomolecular chemistry》2012,10(4):890-894
A divergent and regioselective approach to fused pyridines was developed through formal [3 + 3] cyclocondensations from simple 2,3-unsubstituted chromones or their enaminone precursors. 相似文献
10.
Vahuni Karapetyan Satenik Mkrtchyan Gnuni Karapetyan Alexander Villinger Ashot Saghiyan Tariel V. Ghochikyan Peter Langer 《Helvetica chimica acta》2011,94(11):2045-2053
(Benzyloxycarbonyl)‐protected 3,4‐benzo‐7‐hydroxy‐2,9‐diazabicyclo[3.3.1]non‐7‐enes were prepared by one‐pot cyclizations of 1,3‐bis(silyl enol ethers) with quinazolines. Subsequent hydrogenation resulted in one‐pot deprotection and rearrangement to give 2‐(2‐aminophenyl)‐2,3‐dihydropyridin‐4(1H)‐ones. 相似文献