Pyridine–hydrazone ligands in enantioselective palladium-catalyzed Suzuki–Miyaura cross-couplings
作者:Yolanda Álvarez-Casao、Beatriz Estepa、David Monge、Abel Ros、Javier Iglesias-Sigüenza、Eleuterio Álvarez、Rosario Fernández、José M. Lassaletta
DOI:10.1016/j.tet.2015.12.053
日期:2016.8
The geometries and coordination properties of modular pyridine hydrazone N,N-ligands containing C-2-symmetric trans-2,5-diphenylpyrrolidine and trans-2,5-diphenylpiperidine as the terminal dialkylamino units have been analyzed by X-ray diffraction analysis of [PdCl2(N,N)] complexes [(N,N)=pyridine hydrazone ligand]. In combination with Pd(OAc)(2) as the precatalyst, these ligands provide high enantioselectivities (up to 95:5 er) in asymmetric Suzuki-Miyaura cross couplings of 2-methoxy-1-naphthyl bromides with 1-naphthyl and 2-tolyl boronic acids. (C) 2015 Elsevier Ltd. All rights reserved.