Method for preparing h3-allylpalladium(ii) halide dimer that is unsubstituted or hydrocarbyl-substituted at its h3-allyl groups

A method for preparing [(η3—CR1R2-CR3-CHR4)PdX]2 by reaction of HaNabKc(NH4)dPdX4 with CR1R2=CR3-CHR4-Si(R5)3,

• where a+b+c+d=2,
• where H, Na, K and (NH4) represent hydrogen, sodium, potassium and ammonium,
• where X represents bromine (Br) or chlorine (Cl), wherein
• (i) the substituent groups R1 and R2 are selected, independently of one another, from hydrogen (H), phenyl, methyl, ethyl, n-propyl, isopropyl and the isomeric non-cyclic butyl substituent groups, provided that the substituent groups R1 and R2 are not both phenyl, the substituent groups R3 and R4 are selected, independently of one another, from H, methyl, ethyl and n-propyl, and
• the substituent groups R5 are methyl or ethyl,
• or wherein
• (ii) by means of one of the substituent groups R1 or R2, —CR1R2- together with —CR3- form adjacent ring members of a carbocyclic ring system bonded as a substituent to the —CHR4-carbon,
• the substituent group R2 or R1 which is not involved in the formation of the carbocyclic ring system is selected from H, phenyl, methyl, ethyl, n-propyl, isopropyl and the isomeric non-cyclic butyl substituent groups,
• the substituent group R4 is selected from H, methyl, ethyl and n-propyl, and
• the substituent groups R5 are methyl or ethyl.