Direct Synthesis of Well-Defined Alcohol-Functionalized Polymers via Acyclic Diene Metathesis (ADMET) Polymerization

Abstract

Because of its robust nature, Grubbs' ruthenium benzylidene catalyst RuCl2(CHPh)(PCy3)2 promotes the successful acyclic diene metathesis (ADMET) bulk polymerization of alcohol-functionalized dienes, thus providing a method for the direct synthesis of linear polymers containing hydroxy groups. Primary, secondary, and tertiary alcohol functional groups can be placed at precise intervals along an unsaturated hydrocarbon backbone. Exhaustive hydrogenation of the secondary alcohol homologue produces a well-defined ethylene−vinyl alcohol copolymer. Only the unsaturated and saturated secondary alcohol polymers crystallize, a phenomenon likely attributed to the enhanced packing propensity of these macromolecules in comparison with those of their primary and tertiary analogues.

Poly(p-phenylene alkylene)s – A forgotten class of polymers

“…With the latter, perfectly linear 1,4-polybutadiene 141) , as well as polymers [142][143][144] and copolymers 145,146) of 1,5-hexadiene and 1,9-decadiene with number-average molecular weights, M -n , up to 57 000 142) were synthesized. In addition to the relatively high molecular weights and the readily available monomers, ADMET polymerization proved to be a viable synthetic route to polymers, possessing various functionalities such as ethers 147) , thioethers 148) , silanes 149) , siloxanes 150) , esters 151) , ketones 152) , carbonates 153) , amines 154) , boronates 155) , stannanes 156) , and alcohols 157) . A synthetic route for poly(p-phenylene alkylene)s employing this methodology is, thus, suggested in Scheme 3 f.…”

Unsaturated PA X,20 from Renewable Resources via Metathesis and Catalytic Amidation

“…[6] Due to the development of functional group tolerant metathesis catalysts, it is now possible to polymerize various a,v-dienes bearing ether, ester, ketone, acetal, alcohol, amino acid, boronate, and carboxylic acid functional groups via ADMET polymerization. [7][8][9][10][11][12][13][14] However, attempts to polymerize amide containing a,v-dienes were less successful until now. Tastard et al described the indirect polymerization of a variety of amide containing a,v-dienes by first performing a ring-closing metathesis (RCM) reaction at high dilution in chloroform or THF with 1 mol-% of the Grubbs second generation catalyst to obtain an amide containing macrocycle in moderate to good yields.…”

Synthesis of Polyolefin Block and Graft Copolymers

“…Fu et al [78] reported the direct ring-closing metathesis polymerization of hydroxyl-containing dienes using a well-defined ruthenium-based metathesis catalyst. Valenti and Wagener [80] reported the direct synthesis of precisely defined ethylene-vinyl alcohol copolymers via acyclic diene metathesis polymerization (AD-MET) using ruthenium-based metathesis catalysts. However, the polymer microstructure still shows some randomness in the location of the hydroxyl functionality.…”