The cyclopalladation reaction of benzylamine revisited

The reaction of benzylamine and palladium(II) acetate in a one-to-one molar ratio in toluene or in glacial acetic acid at 60 degreesC for 24 h produced the acetato bridged cyclopalladated dimer of benzylamine (mu-OAC)(2)[Pd(C6H4CH2NH2)](2) (1) in yields of 40-75% and of 20-40%, respectively. In addition, mixtures of compounds 1, 1d1 of formula [(3-DC6H3CH2NH2)Pd](mu-OAc)(2)[Pd(C6H4CH2NH2)] and 1d2 of formula (mu-OAC)(2)[Pd(3-DC6H3CH2NH2)](2) were obtained when benzylamine and palladium(II) acetate in a one-to-one molar were treated in monodeuterated acetic acid (DOAc) at 60 degreesC for 24 h. These mixtures were isolated in yields of 10-30% and deuterium contents in the range between 0.7 and 0.9. Furthermore, the treatment of benzylamine and palladium(II) acetate in a one-to-one molar ratio under reflux of glacial acetic acid for 45 min produced the acetato bridged endo-cyclopalladated dimer of benzyl-benzylidene-amine (mu-OAc)(2)[Pd(C6H4CH=NCH2C6H5)] (compound 4), which was isolated in 14% yield relative to the initial palladium(II) acetate, together with other unidentified compounds. (C) 2002 Elsevier Science Ltd. All rights reserved.