One-pot synthesis of sequence-controlled macromonomers via living anionic addition reaction and subsequent acyclic diene metathesis polymerization

Abstract

We developed a new synthetic approach for sequence-controlled polymers through a 1 : 1 addition reaction, living anionic addition reaction (LAAR) of 1,1-diphenylethylene (DPE) derivatives and acyclic diene metathesis (ADMET) polymerization. Divinyl-functionalized sequence-controlled BAAB-type oligomers were synthesized in high yield by sequentially reacting potassium naphthalenide (K-Naph) with 1,1-bis(4-tert-butyldimethylsilyloxyphenyl)ethylene (OSi, A), DPE (H, B), and an alkyl halide possessing a vinyl group in one pot. Five covalent bonds were quantitatively formed during the reactions, so the desired symmetrical oligomers were easily isolated without tedious purification such as column chromatography. The following ADMET polymerization of the resulting divinyl-functionalized oligomer gave the sequence-controlled polymer with a well-defined BAABR-type repeating unit composed of the DPE tetramer. Our proposed synthetic approach based on the combination of LAAR and ADMET polymerization realized the facile and precise control of the monomer sequence.