Ring closing metathesis , carbene synthesis applications

With the discovery by Grubbs of ruthenium carbene complexes such as Cl2(PCy3)2Ru=CHR, which mediate olefin metathesis under mild reaction conditions and which are compatible with a broad range of functional groups [111], the application of olefin metathesis to solid-phase synthesis became a realistic approach for the preparation of alkenes. Both ring-closing metathesis and cross-metathesis of alkenes and alkynes bound to insoluble supports have been realized (Figure 5.12). 

There are several important applications of the Mo-carbene complex (1) in the synthesis of natural products, illustrating the power of the ring-closing olefin metathesis. Thus, elegant syntheses of coronafacic acid, dactylol, and fluvirucin have been reported. 

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