Degradation of the active species in the catalytic system Pd(OAc)₂/NEt₃

Abstract

The degradation under ambient humidity and room temperature of Pd(OAc)2(NEt3), which is an efficient catalyst for the aerobic oxidation of alcohols, to diethylamine and acetaldehyde derivatives is disclosed.

Amino acid-derived bisphenolate palladium complexes as C–C coupling catalysts

“…45 The latter species -formed through the coordination of hydrolysed HNEt2 to Pd(OAc)2 -was found to be thermally instable, which accounts for the aforementioned decomposition to Pd 0 black particles, especially at temperatures above 40 °C. 46 These simple Pd(OAc)2(amine)2 complexes have been previously observed, as Pd(OAc)2/Et3N catalyst systems are widely applied in the aerobic oxidation of alcohols, where the C-N cleavage forming HNEt2 is considered an unfavourable catalyst degradation process. 47,48 Although the ratio of Pd(OAc)2(NHEt3)2 could be reduced through limiting the excess of NEt3 present in the reaction mixture, the dealkylation could not be completely excluded.…”