The Pd–C/Pb(OAc)2 system catalyzes selective O2-oxidation of ArCH(R)CH2OH to ArCH(R)COOH (useful intermediates for drug synthesis) in high yields without contamination of ArCOOH. The turnover number (substrate/Pd) is improved to 85 and >1800 by recycling the catalyst and using a special reactor, respectively. Alkanols are also efficiently oxidized to alkanoic acids by the title catalyst system.
The liquid-phase oxidation of p-methoxy toluene to p-anisaldehyde in the presence of Co based catalysts has been studied. With Co(OAc)2 alone in acetic acid as a solvent, only a trace amount of p-anisaldehyde could be obtained; however, upon the addition of a second metal salt (e.g., Mn(OAc)2 or Ce(OAc)3) a considerable improvement in the yield (up to 60%) was observed. The synergism of Co and the second component as well as the optimization of the reaction conditions were investigated. Co(OAc)2–Ce(OAc)3–Cr(OAc)3 (3:1:2) was finally found to be the most effective catalytic system, which gave a 76% yield of p-anisaldehyde under 3 atm O2 at 110° for 3 h.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.