Bicyclic Bridgehead Phosphoramidite (Briphos) Ligands with Tunable π-Acceptor Ability and Catalytic Activity in the Rhodium-Catalyzed Conjugate Additions
摘要:
A new type of bicyclic bridgehead phosphoramidites (briphos) is reported, where the geometrical constraints significantly enhance the pi-acceptor ability compared with its monocyclic analogs. The briphos is shown to be highly efficient and tunable for Rh(I)-catalyzed conjugate additions of aryl boronic acids to alpha,beta-unsaturated ketones and N-tosyl ketimines.
Synergistic Ligand Effect between N-Heterocyclic Carbene (NHC) and Bicyclic Phosphoramidite (Briphos) Ligands in Pd-Catalyzed Amination
作者:Miji Kim、Taeil Shin、Ansoo Lee、Hyunwoo Kim
DOI:10.1021/acs.organomet.8b00413
日期:2018.10.8
Buchwald–Hartwig amination reactions was demonstrated with tunable π-acceptor bicyclic bridgehead phosphoramidite (briphos) ligands. The catalytic activity of NHC-Pd-L (L = phosphorus ligand) precatalysts depends on the electronic properties of L. A NHC-Pd-L catalyst with an N-cyclohexyl-substituted briphos ligand was found to be highly efficient. A series of C–N bond coupling reactions between primary or