The stepwise synthesis of a palladium(II) bound alternating oligomer of CO and strained alkenes is described together with the factors that allow full control of each successive step. The sequence starts with acetylpalladium-(II) complexes PdX(COMe)(N-N) (2, 4), (X = Cl(a), Br(b), or I(c); N-N = N,N,N’,N’-tetramethylethylenediamine (tmeda) or 2,2’-bipyridyl (bpy)). The bpy-coordinated acetyl complexes (4a-c) show an unexpected isomerization reaction of the groups around the metal center for which thermodynamic parameters have been determined. A mechanism for the isomerization is proposed. The ionic complexes [Pd(COMe)(MeCN)(N-N)]OTf (5, 6; OTf = trifluoromethanesulfonate), obtained in situ from reaction of 2a-c and 4a-c with AgOTf, react with a number of alkenes. Nonstrained alkenes do insert, but decomposition (probably involving beta-elimination) is fast. Alkenes containing potential donor groups do not insert at all. Only in the case of strained alkenes like norbornene and its derivatives were the insertion products isolated and fully characterized by C-13 NMR, IR, and X-ray analysis. Crystals of the dicyclopentadiene insertion product [Pd(C(10)H(12)COMe)(bpy)]OTf (8c) are monoclinic, space group P2(1)/n, a = 8.3086(4) Angstrom, b = 15.3894(6) Angstrom, c = 18.1479(9) Angstrom, beta = 99.98(1)degrees, V = 2285.36(19) Angstrom(3), Z = 4, R = 0.042 (wR = 0.034). Here, the alkene insertion has occurred in cis,exo fashion on the norbornene-type alkene moiety, indicating this reaction to be both stereo- and chemoselective. The molecular structure shows that the acyl group is coordinated to the metal. Products resulting from a second CO insertion into the Pd-C bond of 8a, i.e. PdX(COC(7)H(10)COMe)-(bpy) (X = C1 (12a) or I (12b)), were formed in the presence of a large excess of a sodium halide salt. Reaction of 12a,b with AgOTf and norbornene gave the alkyl complex [Pd(C(7)H(10)COC(7)H(10)COMe)(bpy)]OTf (13a). Norbornadiene was inserted similarly. Attempted recrystallization of the insertion product of 5-norbornene-endo-2,3-dicarboxylic anhydride (13c) gave the alkyl complex 8a. This is the first example of a reversible alkene insertion reaction on an isolated palladium complex. Addition of CO and excess NaI (20 equiv) to 13a gave the neutral acyl complex PdI(COC(7)H(10)COC(7)H(10)COMe)(bpy) (14), the first isolated and fully characterized CO/alkene oligomer still connected to the palladium(II) catalytic site. Crystals are triclinic, space group P ($) over bar 1 with a = 10.128(2) Angstrom, b = 11.655(2) Angstrom, c = 13.633(2) Angstrom, alpha = 109.89(1)degrees, beta = 100.58(1)degrees, gamma = 92.92(2)degrees, V = 1476.3(4) Angstrom(3), Z = 2 and R = 0.044 (wR = 0.057). Norbornadiene also reacts with 2 equiv. of 5 or 6 to give the homoligated dinuclear complexes [(N-N)Pd{(C7H8)(CoMe)(2)-2,5}Pd(N-N)](OTf)(2) with N-N = tmeda (9) or bpy (10). Crystals of 9 are orthorhombic, space group P2(1)2(1)2(1), a = 11.176(3) Angstrom, b = 11.362(1) Angstrom, c = 30.394(3) Angstrom, V = 3859(1) Angstrom(3), Z = 4, wR2 = 0.124, R = 0.049. In this complex a double alkene insertion reaction has taken place involving both alkene functionalities of a dialkene : 9 is symmetrically substituted with the Pd atoms at opposite (trans) positions.