Double bonds linked by C and N atoms

Ol n Metathesis and Metathesis Polymerization 8.4 Double bonds linked by C and N atoms 

Dienes in which the double bonds are separated by 4, 5, or 6 bonds, and linked through amine or amide functions, readily undergo RCM in the presence of various initiators to yield substituted unsaturated cyclic amines or amides (pyrrolidinones, piperidinones, piperidines) see Table 8.4. 

With catalyst 18 one can also carry out RCM in compounds containing unprotected peptidic stmctures, as illustrated by eqn. (11) (Miller 1995b). 

5 Double bonds Unked by C and O atoms 8.5.1 Ethers and formats 

Examples of such reactions are shown in Table 8.5. Divinyl ether is unreactive but diallyl ether, when treated in bulk with 8, gives an equilibrium mixture of 63% 2,5-dihydrofuran and 37% of its -trans, ring-opened polymer, albeit of low MW (Fig. 8.3). The analogous tungsten complex is not a good initiator for the ADMET polymerization of diallyl ether. 

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