Until now natural fatty acid esters with their internal CC‐bonds cannot be used as substrates for catalytic polymerization reactions. It is always necessary to convert them to terminal unsaturated fatty acid esters first. Therefore, we now developed a two‐catalyst system consisting of an isomerization catalyst and a Brookhart polymerization catalyst. With this system of isomerizing copolymerization (IsoCoP) it is possible to copolymerize high oleic plant oils or fatty acid methyl esters with ethylene in a one‐pot reaction. The resulting polymers have molecular weights above 30 kDa and can contain more than 20 weight percent plant oils. The copolymers of fatty acid methyl esters are soluble in organic solvents. The predominant part of the copolymers from plant oils is usually soluble. The insoluble fraction is soluble after hydrolysis indicating a rare cross‐linking of polyolefin chains by triglycerol units. The catalytic system is effective yielding polymers with a productivity of up to 100 kg polymer per mole catalyst and pretty robust. Plants oils need to be purified only by a simple filtration over alumina before copolymerization. Practical Application: The possibility to copolymerize plant oils with ethylene leads to a new class of polymers and may enhance the usage of plant oils for plastics greatly. The new polymers might be used, e.g., for tackifiers or primers. High oleic plant oils as well as unsaturated fatty acid methyl esters can be directly copolymerized with ethylene by a combination of an isomerization catalyst with a Brookhart polymerization catalyst.

Radical hydrosilylation, hydrogermylation and hydrostannylation without any added initiator may be initiated by alkene‐assisted homolysis of the respective Si‐H, Ge‐H and Sn‐H bond, three more examples of molecule‐assisted homolysis (MAH). We studied the thermally initiated radical addition of tris(trimethylsilyl) silane 1a, tributylgermane 1b, and tributylstannane 1c to methyl 10‐undecenoate 2a and of 1a to 1‐decene 2b. Computed reaction enthalpies and pathways support the radical formation by MAH. These results give evidence that many respective radical reactions without any added initiator reported in literature may be initiated analogously by MAH.

Natural, internal unsaturated fatty acid esters or plant oils can be copolymerized with ethylene in a one‐pot reaction using a two‐catalyst system composed of an isomerization catalyst and a Brookhart‐type polymerization catalyst. The copolymers have molecular weights up to 90 kDa, low (poly‐)dispersity, and are highly branched with low glass transition temperatures.