Synthesis of Sequence-Controlled Polymers via Acyclic Diene Metathesis Polymerization of AA- and BAAB-Type Macromonomers Prepared by Utilizing Nonhomopolymerizability of 1,1-Diphenylethylene Derivatives

Abstract

Sequence-controlled polymers with AAR- and BAABR-type repeating units composed of 1,1-diphenylethylene (DPE) derivatives possessing various functional groups, including trialkylsilyloxy, dodecyl, trimethylsilyl, and bromo substituents, were successfully synthesized in a two-step reaction through the one-pot synthesis of AA- and BAAB-type α,ω-diene macromonomers, followed by acyclic diene metathesis (ADMET) polymerization. Defect-free BAAB-type α,ω-diene macromonomers were quantitatively prepared by the dimerization of a DPE derivative (A) using potassium naphthalenide, a 1:1 living anionic addition reaction of another DPE derivative (B), and a substitution reaction with 5-bromo-1-pentene (5Br1pe). The sequential addition of reagents induced the successive formation of five covalent bonds without side reactions, resulting in a precisely regulated monomer sequence. Similarly, AA-type macromonomers were synthesized by the substitution reaction of precursor AA-type dianions with 5Br1pe. Four AA-type and nine BAAB-type macromonomers were isolated in high yields (71–94%) and subjected to ADMET polymerization to obtain sequence-controlled polymers periodically with functional groups along the main chains.