Ring closing metathesis employing organometallic substrates and the templated synthesis of macrocycles

Templation is a well-known strategy for the selective generation of complex products. Ring-closing metathesis, catalyzed by well-characterized Ru and Mo catalysts, is a powerful method for CC bond formation and has certainly developed into one of the most important modern reactions in organic synthesis and in polymer chemistry. Despite the extensive research on this reaction, the use of organometallic containing substrates is not well-studied. Here, we give a detailed account of our ongoing efforts to employ ring-closing metathesis with bis(α-olefin) substituted pyridines in the presence of trimeric metallopincer templates for the selective synthesis of macroheterocycles with ring sizes up to 81 atoms.

Olefin metathesis has been employed in the selective generation of a number of pyridine containing macroheterocycles using multi-meric rigid pincer platinum complexes as templates. The trispyridine cycles have been used in host–guest chemistry for the complexation of trimeric pincer species. As well, details of the utility and generality of olefin metathesis employing these organometallic substrates are explored. Figure optionsDownload as PowerPoint slide