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1

Reactions of ‘Cage’ Dione with Primary Amines; Revision of an Earlier Report

100%

Romański J.

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2007

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tom Vol. 81, nr 2

187-191

EN

Reactions of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (1, ‘cage’ dione) with primary amines (i.e. benzylamine, aniline, methylamine and 2-aminoethanol) leading to the adducts 4a–d in good yields are described. In all cases the transannular cyclization process was observed and oxa-bridged products 4a–d were obtained. Isolated compounds were identified as hemiacetals or their internal salts. The type of the formed product is dependent on basicity of the used amines. Subsequent dehydration of the initially obtained adducts in boiling benzene led to monoimines 3a–d..

2

RuO4-mediated oxidation of N-benzylated tertiary amines. 3. Behavior of 1,4-dibenzylpiperazine and its oxygenated derivatives

88%

Petride H. , Drăghici C. , Florea C. , Petride A.

Open Chemistry

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2006

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tom 4

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nr 4

674-694

EN

1,4-Dibenzylpiperazine (1),-2-piperazinone (7),-2,6-piperazinedione (9), and 1-benzoyl-4-benzylpiperazine (30) were oxidized by RuO4 (generated in situ) by attack at their endocyclic and exocyclic (i.e., benzylic) aminic N-α-C-H bonds to afford various oxygenated derivatives, including acyclic diformamides, benzaldehyde, and benzoic acid. The reaction outcome was complicated by (i) the hydrolysis of diformamides, occurred during the work-up, and (ii) the reaction of benzaldehyde with the hydrolysis-derived amines giving imidazolidines and/or Schiff bases. Benzoic acid resulted from benzaldehyde only. Compounds 7, 30, and 1-benzylpiperazine, but not 9, were transiently formed during the oxidation of 1. In the same reaction conditions, 1,4-dibenzyl-2,3-(or 2,5)-piperazinedione, 1,4-dibenzyl-2,3,6-piperazinetrione, 4-benzyol-1-benzyl-2-piperazinone, and 1,4-dibenzoylpiperazine were inert. The proposed oxidation mechanism involves the formation of endocyclic and exocyclic iminium cations, as well as of cyclic enamines. The latter intermediates probably result by base-induced deprotonation of the iminium cations, provided an N +−β-proton is available. In the case of 1, the cations were trapped with NaCN as the corresponding α-aminonitriles. The statistically corrected regioselectivity (endocyclic/exocyclic) of the RuO4-induced oxidation reaction of 1, 7, and 30 was 1.2–1.3.

3

RuO4-mediated oxidation ofN-benzylated tertiary amines. Are amineN-oxides and iminium cations reaction intermediates?

88%

Petride H. , Drãghici C. , Florea C. , Petride A.

Open Chemistry

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2004

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tom 2

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nr 2

302-322

EN

N-Benzylmorpholine,-piperidine, and-pyrrolidine (1A-C, resp.) are oxidised by RuO4 (generatedin situ) at both endocyclic and exocyclic (benzylic)N-α-methylene positions to afford lactams (and dioxo-derivatives) and benzaldehyde (and benzoyl derivatives), respectively. TheN-oxides of1A-C, formed by a minor side reaction, are not involved as intermediates. Control experiments showed the transient formation of endo- and exocyclic iminium cations trapped with NaCN as the corresponding nitriles. The proposed course of the RuO4-mediated oxidation of1A-C involves the consecutive steps1⇒iminium cations+cyclic enamine⇒oxidation products. The endocyclic/exocyclic regioselectivity of the oxidation reaction lies between 0.8 (for1A) and 2.1 (for1B). The amine cation radical and theN-α-C· carbon-centered radical seem not to be involved.

4

Wydzielanie jonów Cr(VI) aminami w procesach ekstrakcji i ciekłych membran.

63%

Kozłowski C. , Walkowiak W.

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1998

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tom R. 43, nr 9

420-427

PL

Przedstawiono stan badań procesu ekstrakcji jonowych form chromu(VI) z roztworów wodnych ekstrahentami z grupy Ill-rzędowych amin i IV-rzędowych soli amoniowych. Omówiono budowę i właściwości ekstrakcyjne pochodnych amin w procesie ekstrakcji. Omówiono modele ekstrakcyjne jonów Cr(Vl) z roztworów chlorkowych i siarczanowych w zależności od kwasowości fazy wodnej. Wykazano również przydatność metod wydzielania jonów Cr(Vl) za pomocą ciekłych membran typu: grubowarstwowych, popartych i emulsyjnych zawierających nośniki z grupy amin. Przedstawiono wyniki badań transportu jonów Cr(VI) przez ciekłe membrany z kwaśnych roztworów III-rzędowymi aminami oraz z roztworów zasadowych IV-rzędowymi solami amoniowymi. Procesy te pozwalają na wydzielenie jonów Cr(VI) z 90-procentową wydajnością przy dużej stabilności układu membranowego. Silną tendencję do tworzenia trwałych par jonowych amin z anionami Cr(VI) wykorzystano również do rozdziału jonów Cr(VI) i Cr(III) w procesach ciekłych membran.

EN

The solvent extraction of chromium(VI) ions from aqueous solutions, with the use of tertiary amines and quaternary ammonium salts as extractants, is reviewed. The structure and extraction properties of amine derivatives in the process and the extraction models of Cr(VI) ions from chloride and sulphate solutions, as a function of aqueous phase acidity, are treated. There is presented also the usability of liquid membranes of the type: thick-layer, supported and emulsion liquid membranes, containing carriers of the amine type. The transport of Cr(VI) ions through the liquid membranes out of acidic solutions by 111-order amines and out of alkaline solutions by the IV-order ammonium salts is treated too. Those methods allow to remove up to 90% of CrtVI) with a very stable membrane system. High affinity of Cr(VI) anions with amines was utilized to separate Cr(VI) and Cr(lII) ions in the liquid membran process.

5

Aminy w stabilizacji polioksymetylenu

63%

Pawłowski S. , Tokarz L. , Stasiński J.

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2007

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tom Nr 4

185-190

PL

Zbadano wpływ Chimassorbu l 19 FL na stabilność polioksymctyienu. Dodatek tego stabilizatora spowodował poprawę wskaźnika K220 oznaczającego szybkość degradacji w 220st.C, a więc poprawę tcrmostabilności, ale zwiększył szybkość starzenia się polimeru. Wzrost emisji formaldehydu powierzchniowego oraz zawartości frakcji niestabilnej wskazuje na konieczność dalszych badań.

EN

The results of investigations of polyoxymethylene stabilisation with use of commercial stabiliser Chimassorb 119 FL arc presented. The addition of the stabiliser caused the improvement of polymer thermostability represented by K22o parameter. The growth of the formaldehyde emission from the polymer surface and content of the unstable fraction indicates the necessity of further research.