Use of Hemilabile N,N Ligands in Nitrogen-Directed Iridium-Catalyzed Borylations of Arenes
作者:Abel Ros、Beatriz Estepa、Rocío López-Rodríguez、Eleuterio Álvarez、Rosario Fernández、José M. Lassaletta
DOI:10.1002/anie.201104544
日期:2011.12.2
The hemilabile character of 2‐pyridyl carbaldehyde hydrazones as N,N bidentate ligands is key to performing regioselective IrIII‐catalyzed ortho borylations of 2‐aryl pyridines(isoquinolines) and aromatic N,N‐dimethylhydrazones (see scheme; pin=pinacol, Bn=benzyl). Internal “ate” complexes or products free from NB interactions are formed depending on the steric properties of the substrates.
Synthesis of IAN-type N,N-Ligands via Dynamic Kinetic Asymmetric Buchwald–Hartwig Amination
作者:Pedro Ramírez-López、Abel Ros、Antonio Romero-Arenas、Javier Iglesias-Sigüenza、Rosario Fernández、José M. Lassaletta
DOI:10.1021/jacs.6b07972
日期:2016.9.21
nonaflates with aryl/alkyl primary amines using QUINAP as the ligand provides the corresponding axially chiral heterobiaryl amines with excellent yields and enantioselectivities. Reactivity and structural studies of neutral and cationic oxidative addition intermediates support a dynamic kinetic asymmetric amination mechanism based on the labilization of the stereogenic axis in the latter and suggest that