Scalable ω‐Substituted α‐Olefins via Living Chain Transfer Telomerization: A Platform for Next Generation Polyolefins
Lauren G. Logue, Cole M. Burrows, Vince J. Wedekind, Hyunku C. Kim, Lawrence R. SitaABSTRACT
Isomerically pure, ω‐substituted α‐olefins of general structure, X‐(CH 2 ) m (CH 2 CH 2 ) n ‐1 CH = CH 2 ( m = 0 or 1; X = alkyl or aryl) ( 3 ), have been produced in practical and scalable quantities as narrow Poisson molar mass distributions of separable n ‐mers (e.g. n = 1 – 10) through a one‐pot, two‐step process involving: living ternary chain transfer telomerization of tris(ω‐substituted alkyl)aluminum, [X‐(CH 2 ) m CH 2 CH 2 ] 3 Al ( 1 ), with ethene and a small amount of diethylzinc as a chain transfer mediator, using an in situ generated ion pair initiator derived from the cyclopentadienyl, amidinate (CPAM) Hf pre‐initiator, (η 5 ‐C 5 Me 5 )[κ 2 ‐( N,N’ )‐N(Et)C(Me)N(Et)]HfMe 2 ( 2 ) and the borate co‐initiator, [PhNHMe 2 ][B(C 6 F 5 ) 4 ] ( B ), followed by catalytic displacement of the trialkylaluminum intermediate using bis(1,5‐cyclooctadiene)Ni(0) as the pre‐catalyst. Results are further presented for production of several families of “next generation” polyolefins that are obtained through CPAM Zr‐ and Hf‐mediated stereoselective (enantioselective) living coordination polymerization of different derivatives of 3 and including copolymerization with a variety of linear and branched α‐olefins and 1,5‐hexadiene.