Reactions of m-chloroperoxybenzoic acid with dimeric cyclopalladated complexes derived from 2-phenyl-2-oxazolines

摘要: Cyclopalladated complexes (CPCs) (S,S)-di-μ-Cl(κ2-C,N)2Pd2 (1a,b) and (S,S)-di-μ-OAc(κ2-C,N)2Pd2 (7a,b) obtained from (S)-4-t-butyl-(a) (S)-4-ethyl-2-phenyl-2-oxazoline (b) were reacted with m-chloroperoxybenzoic acid (m-CPBA) at room temperature in methylene chloride, ethyl acetate or acetonitrile followed by workup lithium chloride. Oxidation products formed these reactions include dinuclear (S,S)-di-μ-Cl(κ2-N,O)2Pd2 (2a), (S,S)-di-μ-oxo(κ2-N,O)2Pd2Cl2 (2b), (S,S)-di-μ-(m-Cl-C6H4CO2)(κ2-N,O)2Pd2 (3a,b), mononuclear derivatives (S,S)-bis(κ2-N,O)Pd (4a,b) monooxidation (S,S)-di-μ-Cl(κ2-N,O)(κ2-C,N)Pd2 (5a,b). Each complex was isolated low yield (6–46 %) the combined of oxidation reaching up to 64 %. The best selectivity product distribution observed for μ-OAc–CPCs 7a,b 2.7 equiv. m-CPBA acetonitrile, which oxygen-insertion adducts 2a 4b 44 46 % yields, respectively. structures all supported spectroscopic methods. An X-ray crystallographic study compound 4a performed, confirming its structure revealing an unusual bent geometry.