Designing functional aromatic multisulfonyl chloride initiators for complex organic synthesis by living radical polymerization

The similarities and differences between sulfonyl chloride and alkyl halide initiators for metal-catalyzed living radical polymerizations are discusse d. The differences in the rates of formation, reactivities, and reactions o f primary radicals derived from sulfonyl halides and alkyl halides demonstr ated the design principles for mono-sulfonyl and multisulfonyl chlorides th at provided quantitative initiation and higher rates of initiation than of propagation. Multifunctional initiators with two, three, four, six, and eig ht sulfonyl chloride groups that produced perfect star polymers in 95% conv ersions were designed and synthesized on the basis of these principles. (C) 2000 John Wiley & Sons, Inc.