Artículos de revistas
MaxPHOS Ligand: PH/NH Tautomerism and Rhodium- Catalyzed Asymmetric Hydrogenations
Fecha
2014-03Registro en:
Verdaguer, Xavier; Costantino, Andrea Rosana; Grabulosa, Arnald; Martín Gago, Pablo; Doran, Séan; Etayo, Pablo; et al.; MaxPHOS Ligand: PH/NH Tautomerism and Rhodium- Catalyzed Asymmetric Hydrogenations; Wiley VCH Verlag; Advanced Synthesis & Catalysis (print); 356; 4; 3-2014; 795-804
1615-4150
CONICET Digital
CONICET
Autor
Cristóbal Lecina, Edgar
Etayo, Pablo
Doran, Séan
Revés, Marc
Martín Gago, Pablo
Grabulosa, Arnald
Costantino, Andrea Rosana
Vidal Ferran, Anton
Riera, Antoni
Verdaguer, Xavier
Resumen
MaxPHOS is an active and robust P-stereogenic ligand for asymmetric catalysis. The presence of an NH bridge between the two phosphine moieties allows the NH/PH tautomerism to take place. The neutral ligand, in which the NH form predominates, is an air-sensitive compound. However, protonation of MaxPHOS leads to the stable PH form of the ligand, in which the overall positive charge is distributed on both P centers. This protonation turns the MaxPHOS·HBF4 salt 3 into an airstable compound both in the solid state and in solution. The salt 3 is also a convenient precursor for the preparation of rhodium(I) complexes by direct ligand exchange with the complex [Rh(acac)(cod)]. Finally, the corresponding rhodium(I)-MaxPHOS complex was tested in the asymmetric hydrogenation of a wide range of substrates. The complex proved to be a highly selective and robust system in these reactions.