Iterative Radical Addition with a Special Monomer Carrying Bulky and Convertible Pendant: A New Concept toward Controlling the Sequence for Vinyl Polymers.

Herein we propose a new concept to control sequence for vinyl polymers. A tertiary alkyl methacrylate monomer carrying both adamantyl and isopropyl groups (IPAMA) is very unique to allow control of single unit addition with an alkyl halide initiator for metal-catalyzed living radical polymerization due to the exceptional bulkiness. After control of the single unit addition, the bulkiness can be removed via acidolysis to further convert into the ester pendant with less bulky and nontertiary alcohol. The resultant adduct can be used as an initiator for the next single unit addition of IPAMA and the terminal ester can be selectively hydrolyzed followed by esterification similar to the first process. Namely, the cycle consisting of "radical addition of IPAMA", "acidolysis of the IPAMA side group", and "esterification of resultant carboxylic acid" can be repeated to construct sequence well-defined poly(oligo-)methacrylates. In this letter, results of the cycle and the iterative process with the special methacrylate monomer are actually demonstrated as well as the scope of applicable alcohols for the esterification process toward sequence control with functional units.