Synthesis of linear α-olefins via polyhomologation

Linear α-olefins (LAOs) of controlled molecular weight and low PDI were synthesized in high yield by the polyhomologation reaction of dimethylsulfoxonium methylide (1) with triallylborane (2). Following polymerization, propionic acid or trimethylamine N-oxide dihydrate (TAO) was used to afford α-vinyl-ω-methyl or α-vinyl-ω-hydroxy end-functionalized polymethylene, respectively. Controllable molecular weights up to 13 kDa were obtained by varying the initial monomer/catalyst ratio, and the resultant polymers had very narrow polydispersities (PDI < 1.08). Although polymer yields were generally high, quantities of oxidized side products were observed in α-vinyl-ω-methyl samples; however, these oxidized side products could be removed for samples of low molecular weights (C _n ≤ 36).