SVIBOR - Papers quoted in CC - project code: 1-07-006

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Papers quoted in Current Contents on project 1-07-006


Quoted papers: 5
Other papers: 9
Total: 14


Title: Lack of Secondary beta-Deuterium Kinetic Isotope Effects in the Solvolysis of 2-Chloro-3-hydrosqualene. A Case of Extended pi-Participation and Indication of Concerted Biomimetic Polycyclization

Authors:
Kronja, Olga (23865)
Orlović, Mirko (38572)
Humski, Krešimir
Borčić, Stanko
Journal: Journal of the American Chemical Society
Number: 6
ISSN: 0002-7863
Volume: 113
Year: 1991
Pages: from 2306 to 2308
Number of references: 17
Language: engleski
Summary: 2-Chloro-2-hydrosqualene, its saturated and deuterated analogueswere prepared starting from squalene. These substrates weresubjected to solvolysis and the reaction rates were measured in80% aqueous ethanol. Even though rate effects and activationparameters do not reveal any participation, secondary deuteriumkinetic isotope effect indicates that at least two double CCbonds are involved in the rate determining step, i.e. extendedpi-participation occurs under these conditions.
Keywords: secondary deuterium kinetic isotope effect, extended pi-participation, concerted reaction

Title: Solvolysis Kinetics of 1-Chloro-1-phenyl-5,9,14,18,22-pentamthyl-5,9,13,17,21-tricosapentaene, a Squalene Derivative. Indication of Participation

Authors:
Malnar, Ivica
Kronja, Olga (23865)
Humski, Krešimir
Borčić, Stanko
Journal: Croatica Chemica Acta
Number: 3
ISSN: 0011-1643
Volume: 65
Year: 1992
Pages: from 547 to 549
Number of references: 5
Language: engleski
Summary: The title compound was prepared starting from squalene and thesolvolysis rate and activation parameters were calculated.According to the values obtained it is concluded that thecompound solvolyzes probably with participation of at least onedouble bond.
Keywords: squalene derivative, solvolysis, participation

Title: Deuterium and Carbon-13 Scrambling Processes in Isopropyl Cation

Authors:
Saunders, Martin
Hewett, Alan P.
Kronja, Olga (23865)
Journal: Croatica Chemica Acta
Number: 3
ISSN: 0011-1643
Volume: 65
Year: 1992
Pages: from 673 to 679
Number of references: 13
Language: engleski
Summary: The degenerate rearrangement processes in isopropyl cation werestudied using isotopically double labeled 2-propyl-2-13C-2-d1cation. The first step of the rearrangement is a shift of onemethyl hydrogen to form n-propyl cation, followed by rotation ofthe methylene group. Rotation in one direction (Process I) leadsto formation of isopropyl cation with interchange ofhydrogen, while in other direction (Process II) results aformation of intermediate protonated cyclopropane. Relative ratesof Processes I and II were determined to be 3.4 on the basis ofthe composition of the mixture using Runge-Kutta integration tosimulate the kinetics.
Keywords: isopropyl cation, degenerative rearrangement, protonated cyclopropane

Title: A Kinetic Approach to the Mechanism of Cationic Polyolefinic Cyclization. Simple and Extended pi-Participation

Authors:
Borčić, Stanko
Kronja, Olga (23865)
Humski, Krešimir
Journal: Croatica Chemica Acta
Number: 2
ISSN: 0011-1643
Volume: 67
Year: 1994
Pages: from 171 to 188
Number of references: 38
Language: engleski
Summary: This review deals with mechanism of the biomimetic olefinic cationic polycyclizations considering relative rate effects, activation parameters, substituent rate effects, sigma, ro correlations and secondary deuterium kinetic isotope effects (KIE) in solvolysis, obtained with tertiary and benzylic substrates comprising one, two or more double bonds, respectively, sited at the same positions as in the natural precursors (C-5, C-9, C-13).
Keywords: biomimetic polycyclization, deuterium kinetic isotope effect, pi-participation

Title: 13C and 1H NMR Line Broadening in Desferrioxamine B Spectra. Kinetics and Mechanism of Siderophore Chemistry

Authors:
Biruš, Mladen
Gabričević, Mario
Kronja, Olga (23865)
Klaić, Branimir
Journal: Inorganic Chemistry
ISSN: 1334-3110
Volume: 34
Year: 1995
Pages: from 3110 to 3113
Number of references: 25
Language: engleski
Summary: A slow rotation around C-N bonds of naturallz occuring trishydroxamato acid, desferrioxamine B, was investigated by 1H, 13C dynamic NMR techniques. Correspopnding rate constants for the C-terminal, middle and N-terminal hydroxamates are 12 s-1, 15 s-1, 9 s-1, respectively. The E form of hydroxamate ligands dominates over the Y form in an approximate ratio 4:1. The slow rotation arround the C-N bond of the middle hydroxamato group is proposed to be the rate determining step in dechelation of the middle hydroxamato group. The rate of the E-Z isomerization of the C-terminal group is found to be the rate determinig step in the complexation of La(III) and Cu(II) with desferioxamine B.
Keywords: siderophore chemistry, NMR line broadening, desferrioxamine B


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