Amines, amides, nitriles, and enol ether functional groups, which are frequently present in natural and biologically active substances, are well-tolerated in Mo-, W-catalyzed metathesis reactions.
Link to blog: Schrock, Hoveyda, et al. Org. Lett. 2003, 5, 4899.
Link to blog: Schrock, Hoveyda, et al. J. Am. Chem. Soc. 2005, 127, 8526.
Link to blog: Blechert, et al. Angew. Chem. Int. Ed. 1997, 36, 257.
Link to blog: Hoveyda, et al. Nature 2011, 471, 461.