Allylboration as a versatile tool for the in situ post-polymerization functionalization of 1,4-cis-poly(butadiene)
Allylboration is a versatile tool for the post-polymerization functionalization of poly(butadiene-co-[4,4,5,5-tetramethyl-2-(3-methyl-1,3-butadienyl)-1,3,2-dioxaborolane]). Polar functionalized aldehydes HC(O)C6H4(CH2)R (R = Br, NR2, PPh3, P(O)(OEt)2) react readily with the allyl boronic acid ester groups in the copolymer without interfering with the reactive double bonds in the polymer backbone. This provides access to stereoregular poly(butadiene) functionalized with a broad range of polar groups. Functionalization proceeds under polymerization conditions and therefore does not require a prior polymer work-up.