Electronic Effects on the Bergman Cyclisation of Enediynes. A Review

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Title:Electronic Effects on the Bergman Cyclisation of Enediynes. A Review
Creators:
Klein, Michael
Walenzyk, Thomas
König, Burkhard
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 69, 5, pp. 945-965
Uncontrolled Keywords:Cytotoxic compounds, Antibiotics, Enediynes, Bergman cyclisations, DNA cleavage agents, Alkynes, Electronic substituent effects

Abstract

The thermal cyclisation of enediynes to benzene-1,4-diyl diradicals (Bergman cyclisation) is affected by geometrical and electronic conditions. While the effect of ring strain or conformational constrains on the cyclisation temperature has been investigated in detail, electronic contributions have been less studied. Often geometrical and electronic contributions cannot be clearly distinguished. In most cases metal ion chelation does involve both. In this review we have summarised clear-cut observations of electronic substituents effects on the thermal enediyne reactivity. The effects of substituents in the vinylic and terminal alkyne position, the influence of benzo-fusion and hetarene fusion, as well as the changes induced by heteroatoms in the enediyne skeleton, are within the scope of this review. With the exception of more complex heterocyclic hetarene-fused enediynes the experimental data of electronic substituent effects on the thermal Bergman cyclisation of enediynes follow theoretical predictions. A review with 57 references. <p>

Title:Electronic Effects on the Bergman Cyclisation of Enediynes. A Review
Creators:
Klein, Michael
Walenzyk, Thomas
König, Burkhard
Uncontrolled Keywords:Cytotoxic compounds, Antibiotics, Enediynes, Bergman cyclisations, DNA cleavage agents, Alkynes, Electronic substituent effects
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:69
Number:5
Page Range:pp. 945-965
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20040945UNSPECIFIED
ID Code:2254
Item Type:Article
Deposited On:06 Feb 2009 17:17
Last Modified:06 Feb 2009 16:17

Citation

Klein, Michael; Walenzyk, Thomas; König, Burkhard (2004) Electronic Effects on the Bergman Cyclisation of Enediynes. A Review. Collection of Czechoslovak Chemical Communications, 69 (5). pp. 945-965. ISSN 0010-0765

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