Metathesis Catalyst

The ring closing metathesis (RCM) reaction in which metal carbene complexes are used as catalysts is a useful way to afford a new carbon-carbon bond formation by recombinating the bond between terminal olefins. As an example of metal carbene complexes, ruthenium analogues represented by Grubbs catalyst, are widely used because of their high functional group selectivity for olefin. The compoumd 1, another example of a ruthenium carbene complex, is stable in the atmosphere and shows high catalytic activity in the RCM reaction. The total synthesis of various natural products using the RCM reaction with 1, which is situated as key reaction, have been reported.