STEPWISE SUCCESSIVE INSERTION OF CARBON-MONOXIDE AND ALLENES INTO PALLADIUM-CARBON BONDS OF COMPLEXES CONTAINING THE RIGID BIDENTATE NITROGEN LIGAND BIS(P-ANISYLIMINO)ACENAPHTHENE

Propadiene, 3-methyl-1,2-butadiene (DMA), and 2,4-dimethyl-2,3-pentadi ene (TMA) reacted via migratory insertion with both neutral and ionic Pd(R)X(p-An-BIAN) (R = Me (1), C(O)Me (2); X = Cl (a), SO3CF3 (b)) com plexes, containing the rigid nitrogen ligand bis(p-anisylimino)acenaph thene (p-An-BIAN), resulting in the novel and stable allylpalladium co mplexes Pd(eta(3)-C(3)H(4)R)X(p-An-BIAN) (R = Me (3), C(O)Me (6)), Pd( eta(3)-C(5)H(8)R)X(p-An-BIAN) (R = Me (4), C(O)Me (7)), and Pd(eta(3)- C(7)H(12)R)X(p-An-BIAN) (R = Me (5), C(O)Me (8)), respectively (X = Cl (a), SO3CF3 (b)). The neutral complexes 6a and 7a reacted with carbon monoxide to form the acylpalladium complexes Pd(C(O)C3H4C(O)Me)Cl(p-A n-BIAN) (9) and Pd(C(O)C5H8C(O)Me)Cl(p-An-BIAN) (10), respectively, wh ile the analogous trifluoromethanesulfonate complexes 6b and 7b were c ompletely inert toward CO. Complexes 9 and 10 reacted again with propa diene and DMA, respectively, to yield the allylpalladium complexes Pd( eta(3)-C3H4C(O)C3H4C(O)Me)Cl(p-An-BIAN) (11) and Pd(eta(3)-C5H8C(O)C5H 8C(O)Me)Cl(p-An-BIAN) (12), respectively. Also insertion of norbornadi ene in complex 10 was possible, yielding the ionic complex [Pd(C7H8C(O )C5H8C(O)Me)(p-An-BIAN)]Cl (13a), which reacted with AgSO3CF3 to give [Pd(C7H8C(O)C5H8C(O)Me)(p-An-BIAN)]SO3CF3 (13b). The novel complexes 9 -12 are the first isolated and fully characterized complexes formed by successive insertion reactions of carbon monoxide and allenes, while 13a is the first isolated complex containing a metal-bonded ter-oligom er of carbon monoxide, an allene, and norbornadiene. The X-ray crystal structure of 7a has been determined and shows a distorted square pyra midal geometry in which the BIAN ligand is bonded to the palladium cen ter in an unusual asymmetric fashion (Pd-N(1)= 2.144(7) Angstrom; Pd-N (2)= 2.600(8) Angstrom).