Oligomerization of one or more olefins is carried out over 2 or more transition metal catalysts, one a tetramerization catalyst and a higher oligomerization catalyst, both of which contain bulky ligands. The tetramerization catalyst consists of a transition metal compound (preferably a Group IV to VI transition metal complex) and a ligand of general formula (R1)mX1-(Y)-X2(R2)n (X1 and X2 = N, P, As, Sb, Bi, O, S, and Se; Y is a linking group; m,n = 0 or more; R1 and R2 = H, hydrocarbyl, and heterohydrocarbyl). The higher oligomerization catalyst also consists of a transition metal compound and a ligand of general formula (R3)m-A-B-C(R4)m (A and C = N, P, As, Sb, Bi, O, S, and Se; B is a linking group; m,n = 0 or more; and R3 and R4 = H, hydrocarbyl, or heterohydrocarbyl). The catalysts can optionally contain an activator (e.g., an alumoxane).
Please note: Titles and abstracts are routinely enhanced for patent records in CAplus to better describe the claimed invention. In this example, CAS enhanced both the title and the abstract using additional information found in the patent.
View the full-text U.S. patent from USPTO.