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.
Dynamic Kinetic Cross-Coupling Strategy for the Asymmetric Synthesis of Axially Chiral Heterobiaryls
作者:Abel Ros、Beatriz Estepa、Pedro Ramírez-López、Eleuterio Álvarez、Rosario Fernández、José M. Lassaletta
DOI:10.1021/ja4087819
日期:2013.10.23
A dynamic kinetic asymmetric transformation (DYKAT) technique has been designed for the synthesis of 2'-substituted 2-aryl pyridines/isoquinolines and related heterobiaryls. In this way, the Pd(0)-catalyzed coupling of racemic 2-triflates with aryl boroxines using a TADDOL-derived phosphoramidite as the ligand provides the corresponding coupling products with good to excellent enantioselectivities
Strongly Emissive and Photostable Four‐Coordinate Organoboron N,C Chelates and Their Use in Fluorescence Microscopy
作者:Vânia F. Pais、María M. Alcaide、Rocío López‐Rodríguez、Daniel Collado、Francisco Nájera、Ezequiel Pérez‐Inestrosa、Eleuterio Álvarez、José M. Lassaletta、Rosario Fernández、Abel Ros、Uwe Pischel
DOI:10.1002/chem.201501626
日期:2015.10.19
Six strongly fluorescent four‐coordinateorganoboronN,Cchelates containing an aryl isoquinoline skeleton were prepared. Remarkably, the fluorescence quantum yields reach values of up to 0.74 in oxygen‐free toluene. The strong BN interaction was corroborated by the single‐crystal X‐ray analysis of two dyes. The intramolecular charge‐transfer character of the fluorophores was evidenced by solvatochromism
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