Synthesis of Poly(macromonomer)s by Repeating Ring-Opening Metathesis Polymerization (ROMP) with Mo(CHCMe_2Ph)(NAr)(OR)_2 Initiators

摘要

Various poly(macromonomer)s of ring-opened poly(norbornene) backbone containing ring-opened poly(norbornene) derivatives in the side chain have been prepared efficiently by repeating the ring-opening metathesis polymerizations (ROMP) using well-defined molybdenum initiator of the type, Mo(CHCMe_2Ph)(N-2,6-~iPr_2C_6H_3)(OR)_2 [OR = OCMe_3, OCMe(CF_3)_2]. The key steps for synthesis of the macromonomer are both exclusive end-capping and quantitative esterification of hydroxy group at the polymer chain end with norbornene carboxylic acid chloride, and the use of Mo(CHCMe_2Ph)(N-2,6-~i-Pr_2C_6H_3)[OCMe(CF_3)_2]_2 was found to be an effective initiator in order for this polymerization to proceed to the complete conversion. The present synthetic approach should be useful for preparing various poly-(macromonomer)s containing functional groups, especially amphiphilic poly(macromonomer) architectures precisely.