The phenol countdown: Novel imidazole‐based phosphineligands are synthesized on scales up to 100 g by a convenient lithiation–phosphorylation method. The phosphines are stable towards air and moisture and are successfully applied as ligands in the palladium‐catalyzed selectivehydroxylation of arylhalides (see scheme, dba=dibenzylideneacetone).
2-Phosphinoimidazole Ligands: N–H NHC or P–N Coordination Complexes in Palladium-Catalyzed Suzuki–Miyaura Reactions of Aryl Chlorides
作者:Erin E. Martinez、Alexandra J. S. Larson、Sydney K. Fuller、Kathryn M. Petersen、Stacey J. Smith、David J. Michaelis
DOI:10.1021/acs.organomet.1c00165
日期:2021.6.14
for Suzuki–Miyaura reactions with (hetero)arylchlorides at room temperature. Our mechanistic studies demonstrate that these palladium complexes exist as an equilibrium mixture between the P–N coordinated and N–H NHC forms of ligand. Our studies suggest that the N–H NHC form may be important for high catalytic activity in Suzuki–Miyaura reactions with arylchlorides. These reactions proceed at or near