Synthesis, Structural Studies, and Catalytic Application of Palladium Complexes Containing Anilido‐Oxazolinate Ligands

Abstract

AbstractA series of palladium anilido‐oxazolinate complexes 1–8 prepared from ligand precursors HNArOxa [ortho‐C6H4(NHAr)(4,4‐dimethyl‐2‐oxazoline) where Ar = 2,4,6‐trimethylphenyl, HNPhTriMeOxa; 2,6‐diisopropylphenyl, HNPhDiiPrOxa; phenyl, HNPhHOxa; 2‐methoxyphenyl, HNPhOMeOxa; 2‐methylthiophenyl, HNPhSMeOxa] is reported. Treatment of HNArOxawith 1.1 equiv. Pd(OAc)2 afforded palladium(II) acetate complexes (NPhTriMeOxa)Pd(η2‐OAc) (1) and (NPhDiiPrOxa)Pd(η2‐OAc) (2) as monomeric complexes, [(NPhHOxa)Pd(OAc)]2 (3) as an anilido‐bridged dinuclear complex, [(NPhOMeOxa)Pd(OAc)]2 (4) as an acetate‐bridged dinuclear complex, and (NPhSMeOxa)Pd(OAc) (5) as a monomeric complex. The reactions of 2, 4, and 5 with an excess of NaCl(aq.) in acetone yielded palladium(II) chloride complexes, [(NPhDiiPrOxa)Pd(Cl)]2 (6) as a chloro‐bridged dinuclear complex, (NPhOMeOxa)Pd(Cl) (7) as a monomeric complex, [(NPhOMeOxa)Pd(Cl)]2 (7′) as an anilido‐bridged dinuclear complex, and (NPhSMeOxa)Pd(Cl) (8) as a monomeric complex. The crystal and molecular structures of 1–8 are reported, and their application towards Suzuki and Heck reactions with a wide range of aryl halides has been examined.