Research Library

Premium Imidovanadium( V ) Complexes as Reaction Partners for Kinetically Stabilized Phosphaalkynes: Synthesis of 1,2,4‐Azaphosphavanada( V )‐cyclobutenes, 1,3,5‐Triphosphabenzenes, and 1 H ‐1,2,4‐Azadiphospholes
Tabellion Frank,
Peters Christoph,
Fischbeck Uwe,
Regitz Manfred,
Preuss Fritz
Publication title
chemistry – a european journal
Resource typeJournals
PublisherWILEY‐VCH Verlag
Abstract Cycloaddition reactions of the kinetically stabilized phosphaalkynes 1 with the imidovanadium( V ) trihalides 9 furnish the 1,2,4‐azaphosphavanada( V )cyclobutenes 10 . The stability of these novel metallacyclic compounds depends solely on the substitutents of the imido unit. Thus, the imidovanadium( V ) species 9 with tertiary alkyl groups on the N atom form stable addition products with 1 while in the cases of compounds 9 with a lower degree of substitution at N (primary and secondary alkyl groups) the primarily formed adducts 10 undergo irreversible decomposition to afford the 1 H ‐1,2,4‐azadiphospholes 13 . Reactions of an excess of the phosphaaalkyne 1 with the vanadium complexes 9 furnish the corresponding triphosphabenzenes 8 in good yields (36–68 %). A catalytic reaction course has been demonstrated for the all‐ tert‐ butyl system 1 a/9 a in which the metallacyclic species 10 a serves as the catalytically active species. Poisoning of the catalyst leads to a second reaction pathway, which results in formation of the azatetraphosphaquadricyclanes 16 . By means of the stepwise use of different phosphaalkynes 1 a , b this methodology provides the first access to the differently substituted triphosphabenzenes through cyclotrimerization.
SCImago Journal Rank1.687

Seeing content that should not be on Zendy? Contact us.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here