507 research outputs found

    Alternative conditions for the synthesis of novel spiro[1,3-N,N-heterocyclic-adamantanes]

    Get PDF
    A series of new spiro[N-heterocyclic-adamantanes] was synthesized through the reaction of 2-adamantanone with beta-amino carboxamides. Depending on the chemical and physical characteristics of the starting compounds, the cyclocondensations proceeded under simple and mild (aqueous, solvent-free, ball-milling or/and microwave-assisted) conditions with no necessity for chromatographic purification of the products. The reaction was extended to leucinamide and salicylamide

    Syntheses, transformations and applications of aminonaphthol derivatives prepared via modified Mannich reactions

    Get PDF
    A special alteration is the three-component modi fi ed Mannich reaction (mMR), in which formaldehyde is replaced by an aromatic aldehyde, the secondary amine by ammonia, and the C e H acid by an electron-rich aromatic compound such as 1- or 2-naphthol, quinolinol or isoquinolinol. Based on this, it can be interpreted as a formal Mannich reaction. Starting from ammonia, benzaldehyde, and 2-naphthol in this mMR, 100 years ago, Mario Betti reported the straightforward synthesis of 1,3-diphenylnaphthoxazine in methanol. Acidic hydrolysis of the ring compound produced led to 1-aminobenzyl-2-naphthol. The aminonaphthol product became known in the literature as a Betti base, and the protocol as the Betti reaction. 3 e 5 This reaction has subsequently been extended by using different N sources, the order and character of which (ammonia, amine or amide) greatly determine the reaction conditions and the method of isolation of the Mannich product. 6 On the other hand, the use of non-racemic amines has opened up a new area of ap- plication of enantiopure aminonaphthols as chiral catalysts in enantioselective transformations

    Multifrekvenciás elektron spin rezonancia erősen korrelált fémekben és szupravezetőkben = Multifrequency electron spin resonance in strongly correlated metals and superconductors

    Get PDF
    A projekt célja olyan szilárd testek elektron spin rezonancia vizsgálata, amelyekben az elektron-elektron korrelációk alapvetően fontosak. A vizsgált kuprát, szerves és fullerén vegyületek fémek, szupravezetők vagy a szupravezetéshez közel álló mágnesesen rendezett anyagok, amelyekben az elektron korrelációnak lényeges szerepe van. Megmértük és egy elméletet dolgoztunk ki a MgB2 szervetlen szupravezető vezetési elektron spin élettartamára, ami alapvető fizikai mennyiség. Befejeztük egy, a magas hőmérsékletű szupravezetéshez közel álló kuprát rendszer mágneses fázis diagramjának meghatározását. Az ET2Cu[N(CN)2]Cl réteges szerves gyenge ferromágnes rezonancia módusainak feltérképezésével egy régóta megfejthetetlen problémát oldottunk meg egy, a szupravezetés és mágnesség határán lévő anyagra. A Parmai Egyetem (Olaszország) és a Cambridge-i Egyetem (Nagy Britannia) kutatóival együttműködve megmutattuk, hogy a Li4C60 fullerén vegyület egy ionos vezető, amely alkalmazható lehet elektromos telepekben. Az eredményeket magas impaktú tudományos folyóiratokban közöltük. A munka két PhD tézis alapjául szolgált. Az ESR spektrumok fejlődése megújította az érdeklődést a módszer iránt. A nagy frekvenciás ESR spektrométert felújítottuk, új kvázi-optikai hidat, nagyteljesítméníű mm-hullámú forrást, mérőfejeket és egy rezgésmentes tartószerkezetet helyeztünk üzembe. Az érzékenységet egy nagyságrenddel megnöveltük. | The aim of the project was an electron spin resonance investigation of solids in which electron-electron correlations are of fundamental importance. The cuprate, organic and fullerene compounds investigated are metals, superconductors or magnetically ordered systems related to superconductivity in which electron correlations play an essential role. We measured and proposed a theory of the conduction electron spin life time in an inorganic superconductor, MgB2. We completed work on the magnetic phase diagram of a cuprate system close to high temperature superconductivity. The mapping of the magnetic resonance modes of a layered organic weak ferromagnet, ET2Cu(N(CN)2)Cl, solved a long standing problem of a material at the borderline of magnetic order and superconductivity. We showed, in collaboration with researchers at the University of Parma (Italy) and University of Cambridge (UK) that the fullerene compound, Li4C60 is a crystalline superionic conductor with possible applications in electrical batteries. Results were published in high impact scientific journals. The work served the basis for the completion of two PhD thesis. The recent progress of high frequencies ESR spectrometers has renewed interest in the method. The high frequency ESR spectrometer has been reconstructed, a new quasi optical bridge, a powerful mm-wave source, probe heads and a vibration free supporting structure were installed. As a result the sensitivity was increased by an order of magnitude

    Fluorination of some functionalized cycloalkenes through epoxidation and oxirane opening with Deoxofluor or XtalFluor-E

    Get PDF
    A convenient, simple synthetic method is described for the synthesis of some fluorinecontaining, highly functionalized cycloalkane derivatives. The synthetic protocol involves the stereoselective epoxidation of selected substituted cyclohexenes as model compounds, followed by regioselective opening of epoxides under various conditions with fluorinating reagents Deoxofluor and XtalFluor-E

    BEFRIEND - a benchmark for evaluating reverse engineering tools

    Get PDF
    Reverse engineering tools analyze the source code of a software system and produce various results, which usually point back to the original source code. Such tools are e.g. design pattern miners, duplicated code detectors and coding rule violation checkers. Most of the time these tools present their results in different formats, which makes them very difficult to compare. In this paper, we present work in progress towards implementing a benchmark called BEFRIEND (BEnchmark For Reverse engInEering tools workiNg on source coDe) with which the outputs of reverse engineering tools can be easily and efficiently evaluated and compared. It supports different kinds of tool families, programming languages and software systems, and it enables the users to define their own evaluation criteria. Furthermore, it is a freely available web-application open to the community. We hope that in the future it will be accepted and used by the community members to evaluate and compare their tools with each other
    corecore