Premium
Isomerization, Ring Expansion, and Ring Contraction of 1,3‐Diphosphete Complexes
Author(s) -
Rummel EvaMaria,
Balázs Gábor,
Heinl Veronika,
Scheer Manfred
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201703633
Subject(s) - isomerization , chemistry , pyridine , stereochemistry , ring (chemistry) , thermal decomposition , contraction (grammar) , hexane , medicinal chemistry , catalysis , organic chemistry , medicine
Reactions between the 1,3‐diphosphete complex [Cp′′′Co(η 4 ‐P 2 C 2 tBu 2 )] ( 1 ) and Ag[Al{OC(CF 3 ) 3 } 4 ] (Ag[pftb]) were carried out under different conditions. In CH 2 Cl 2 , the unprecedented 1,2‐diphosphete isomerization product [Ag 2 {Cp′′′Co(μ,η 4 :η 1 :η 1 ‐1,2‐P 2 C 2 tBu 2 )} 2 {Cp′′′Co(μ,η 4 :η 1 ‐1,2‐P 2 C 2 tBu 2 )} 2 ]⋅2[pftb] ( 2 ) could be isolated. In diffusion experiments of 1 in n‐hexane with Ag[pftb] in CH 2 Cl 2 , the triphosphacobaltocenium complex [Cp′′′Co(η 5 ‐P 3 C 2 tBu 2 )][pftb] ( 4 ) and the phosphirenylium complex [Cp′′′Co(η 3 ‐PC 2 tBu 2 )][pftb] ( 5 ) were obtained, showing a ring expansion and a ring contraction, respectively, under mild conditions. Moreover, addition of pyridine to the Ag complex 2 led to the new 1,2‐diphosphete complex [Cp′′′Co(η 4 ‐1,2‐P 2 C 2 tBu 2 )] ( 3 ). Compound 3 is also formed by thermolysis of 1 , making it a promising method for this type of isomerization. 1,2‐Diphosphete complexes like 3 are thermodynamically more stable but also synthetically more elusive than their 1,3‐isomer counterparts.