M. C. White/ Chem 153 Oligomerization -305 Week of november 18. 2002 SHOP Shell Higher Olefin Process) ate metal is highly tolerant of oxygenated SHOP process is operated on a I million ton activity=6000 mol ethylene/mol Ni capacity and constitutes one of the largest (40am) 50C. tolt 99%linear can be run in acetone or EtOh) Keim and Kruger ACIEE 1978(17)466 Keim ACIEE 1990(29)235 Proposed mechanism: Catahyst activation Ph2 Ph2 Ph If there is B-hydride elimination, why don't we see Formation of the bis ligand associative displacement of the a-olefin oligomer is complex results in irreversible pid relative to cis hydrometallation to the branched Kyl 2. branched alkyl insertion into ethylene is Ittel J Mol Catal. 1987(41)123 入 B-hydride elimination propagation)M.C. White/ Chem 153 Oligomerization -305- Week of November 18, 2002 SHOP (Shell Higher Olefin Process) P O NiII Ph PPh3 SHOP process is operated on a 1 million ton capacity and constitutes one of the largest applications of homogeneous catalysis by a transition metal. (40 atm) 50 oC, toluene n 99% linear 98% α-olefins up to C30 late metal is highly tolerant of oxygenated functionality activity = 6000 mol ethylene/mol Ni Keim and Kruger ACIEE 1978 (17) 466. Keim ACIEE 1990 (29) 235. Catalyst activation: Ph2 P O NiII Ph Ph PPh3 Ph2 P O NiII Ph Ph PPh3 Ph2 P O NiII Ph Ph H Ph2 P O NiII Ph H Ph2 P O NiII Ph H Ph2 P O NiII Ph Ph2 P O NiII Ph H Ph2 P O NiII Ph H n n hydride migratory insertion/ ethylene association alkyl migratory insertion/ ethylene assocation, repeat.. (propagation) termination via β-hydride elimination n associative displacement If there is β-hydride elimination, why don't we see significant branching? Possibilities include 1. associative displacement of the α-olefin oligomer is rapid relative to cis hydrometallation to the branched alkyl 2. branched alkyl insertion into ethylene is unfavorable. Ph2 P O NiII Ph n Ph2 P O NiII Ph n etc.. branching pathway Proposed mechanism: (can be run in acetone or EtOH) Ph2 P O NiII Ph Ph2 P O Ph Formation of the bis ligand complex results in irreversible catalyst inactivation. Ittel J. Mol. Catal. 1987 (41) 123