A potential new RAFTClick reaction or a cautionary note on the use of diazomethane to methylate RAFT-synthesized polymers

Ming Chen, Graeme Moad, Ezio Rizzardo

Research output: Contribution to journalArticleResearchpeer-review

6 Citations (Scopus)

Abstract

It has been found that diazomethane undergoes a facile 1,3-dipolar cycloaddition with both dithiobenzoate RAFT agents and the dithiobenzoate end-groups of polymers formed by RAFT polymerization. Thus, 2-cyanoprop-2-yl dithiobenzoate on treatment with diazomethane at room temperature provided a mixture of stereoisomeric 1,3-dithiolanes in near quantitative (>95%) yield. A low-molecular-weight RAFT-synthesized poly(methyl methacrylate) with dithiobenzoate end-groups underwent similar reaction as indicated by immediate decolourization and a quantitative doubling of molecular weight. Higher-molecular-weight poly(methyl methacrylate)s were also rapidly decolourized by diazomethane and provided a product with a bimodal molecular weight distribution. Under similar conditions, the trithiocarbonate group does not react with diazomethane.

Original languageEnglish
Pages (from-to)433-437
Number of pages5
JournalAustralian Journal of Chemistry
Volume64
Issue number4
DOIs
Publication statusPublished - 2011
Externally publishedYes

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