Jx. Wang et al., SOLID-LIQUID PHASE-TRANSFER AND COBALT OR PALLADIUM COMPLEX-CATALYZEDSYNTHESIS OF ANHYDRIDES FROM ACYL CHLORIDES, Synthetic communications, 24(22), 1994, pp. 3261-3268
Acyl chloride can efficiently be converted into anhydride under solid
liquid phase transfer catalysis by using bis(triphenylphosphine)cobalt
dichloride or bis(triphenylphospine)palladium dichloride as catalyst.