Diimine Pd(II) chelates are prepared with an activated ester moiety which can be used to install initiating groups for ring-opening polymerizations (ROP) and controlled radical polymerizations (CRP). With this, a practical access to polyolefin block copolymers are achieved with unprecedented variety of the choice of monomers to prepare the second segment of the block copolymer, such as esters, ethers acrylic and vinylic monomers. The ability to polymerize the second block copolymer from the polyolefin block copolymer depends on the nature of the installed initiator and with this technique it is an option to perform a light initiated MILRad technique to achieve a block copolymer through free radical polymerization or perform a ROP or CRP through the chosen initiating unit. The achieved block copolymers contain then not only segments of polyolefins but also polyacrylates, polyvinyls, polyesters and polyethers. Polyolefin block copolymers with these segments can find applications in many fields such as advanced plastic materials, plastic recycling, plastic foils for food packaging and biomedical applications. The broadness of the achievable block copolymers is unmatched by using this technique.