text: Many template reactions are only stoichiometric, and the decomplexation of the "templating ion" can be difficult. The alkali metal-templated syntheses of crown ether syntheses are notable exceptions. Metal Phthalocyanines are generated by metal-templated condensations of phthalonitriles, but the liberation of metal-free phthalocyanine is difficult.
  Some so-called template reactions proceed similarly in the absence of the templating ion. One example being the condensation of acetone and ethylenediamine, which yields isomeric 14-membered tetraaza rings.  Similarly, porphyrins, which feature 16-membered central rings, form in the absence of metal templates.