ISSN:
0947-6539
Keywords:
alkyne complexes
;
carbene complexes
;
chelates
;
chromium
;
chrysenes
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Tetracarbonyl-π2-alkyne-carbene chromium(0) complexes 3a-c stabilized by a rigid C2-arene unit bridging the alkyne and the carbene ligands were synthesized from their pentacarbonyl precursors 2a-c by low-temperature photodecarbonylation. The chelates 3a-c are the first stable alkyne-carbene complexes containing a Group VIB metal carbonyl unit, and can be regarded as arrested intermediates in the chromium-mediated benzannulation reaction. Comparative X-ray and 13C NMR studies indicate only weak coordination of the alkyne, both in the solid state and in solution. Decomposition of chelates 3a-c as well as the thermal decarbonylation of their pentacarbonyl precursors 2a-c results in dimerization of the alkynylcarbene ligands to give densely substituted oxygenated chrysene derivatives. A modification of the substitution pattern in the central chrysene rings results in a gradual distortion of the arene system across the central C—C arene bond.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19970030605
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