Synthesis of aldehydes and ketones through carbonylation of (9-methoxytricyclo[5,2,1,02,6]dec-4-en-8-yl) triphenylphosphinepalladium(II) chloride

Abstract

The complex [Pd(C₁₀H₁₂OMe)(PPh₃)Cl](1) reacts with carbon monoxide in aprotic solvents to give an intermediate which i.r. and n.m.r. spectra indicate to be [Pd{(C₁₀H₁₂OMe)(CO)}(PPh₃)(CO)Cl](2). This intermediate, which could not be isolated, reacts with phenyl- or methyl-lithium to yield unsaturated ketones of the type RCO·C₁₀H₁₂·OMe with concomitant reduction of Pd^II to metallic palladium. The reaction of (2) with methyl iodide or hydrogen chloride gives the corresponding ketone or aldehyde, respectively, with formation of a palladium(II) dimeric complex. Compound (1) reacts with acetyl chloride to give a Pd^II dimeric complex and the ketone MeCO·C₁₀H₁₂·OMe which is the same as that obtained by reaction with carbon monoxide and methyl iodide.