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 C=C bond formation and has certainly developed into one of the most important modem 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(alpha-olefin) substituted pyridines in the presence of trimeric metallopincer templates for the selective synthesis of macroheterocycles with ring sizes up to 81 atoms. (c) 2006 Elsevier B.V. All rights reserved.