ALVAREZ LORENZO, DANIEL, Diaz, Jesus , Isabel Menendez, M. , Lopez, Ramon
No
Eur. J. Inorg. Chem.
Article
Científica
2.524
0.667
23/01/2020
000506127400001
Reactions between [Re(X)(CO)(3)(bipy)] (X = OH, OMe, NHpTol, PPh2; bipy = 2,2 '-bipyridine) complexes and methyl propiolate (HMAD) are studied to rationalize the different products experimentally obtained. Three reaction patterns were found with a common and limiting initial attack of X to HMAD. Thus, the experimental selectivity depends on the kinetics and/or thermodynamics of the last reaction stages. For X = OH and NHpTol an easy intramolecular attack of the X-linked HMAD to a highly electrophilic CO ligand is followed by a hydrogen transposition to this CO, yielding very stable species (C-C-COH products). When X = OMe, the insertion of the X-attached HMAD into the Re-OMe bond (ins product) takes place due to the smallest barrier and the largest stability of the ins route. Finally, when X = PPh2 the ins route becomes restricted and the route for the coupling of the X-attached HMAD with bipy (C-C-bipy product) wins over the one for the coupling with CO (C-C-CO product) only due to the larger stability of the C-C-bipy product.
Rhenium; Nucleophilic addition; Ligand effects; Reaction mechanisms; Computational chemistry