Isomerisierung, Ringerweiterungs- und Ringverengungsreaktionen von 1,3-Diphosphet-Komplexen

Autor: Manfred Scheer, Gábor Balázs, Eva-Maria Rummel, Veronika Heinl
Rok vydání: 2017
Předmět:
Zdroj: Angewandte Chemie. 129:9720-9725
ISSN: 0044-8249
DOI: 10.1002/ange.201703633
Popis: Reactions between the 1,3-diphosphete complex [Cp'''Co(η4-P2C2tBu2)] (1) and Ag[Al{OC(CF3)3}4] (Ag[pftb]) were carried out. In CH2Cl2, the unprecedented 1,2-diphosphete isomerization product [Ag2{Cp'''Co(µ,η4:η1:η1-1,2-P2C2tBu2)}2{Cp'''Co(µ,η4:η1-1,2-P2C2tBu2)}2]·2[pftb] (2) could be isolated. In diffusion experiments of 1 in hexane with Ag[pftb] in CH2Cl2, the triphosphacobaltocenium complex [Cp'''Co(η5-P3C2tBu2)][pftb] (4) and the phosphirenylium complex [Cp'''Co(η3-PC2tBu2)][pftb] (5) were obtained, showing a ring expansion and a ring contraction, respectively, under mild conditions. Moreover, by addition of pyridine to the Ag complex 2, the novel 1,2-diphosphete complex [Cp'''Co(η4-1,2-P2C2tBu2)] (3) was released. The formation of 3 has also shown to be possible by thermolysis of 1. Compound 3 represents a rare example of the family of the 1,2-diphosphete complexes, which are thermodynamically more stable but also synthetically more elusive than their 1,3-isomer counterparts.
Databáze: OpenAIRE
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