Stereo- and regioselective cyclopolymerization of chiral 1,7-octadiynes

摘要: A series of diastereomeric 4,5-diethoxycarbonyl-1,7-octadiynes were synthesized from which the pure diastereomers obtained by selective Soxhlet extraction in CHCl3. The concept “small alkoxides” was used with varying size alkoxide ligands and all monomers cyclopolymerized two different Schrock-type initiators. As a result, poly(1,7-octadiyne)s consisting virtually solely six membered repeat units via regioselective α-insertion. structure polymers regioselectivity insertion further confirmed comparing 13C NMR shifts model compounds those corresponding polymers. living character polymerization demonstrated kinetic studies end group analysis MALDI-ToF MS; diblock copolymers successfully prepared 1,7-octadiynes 1,6-heptadiynes. Finally, tacticity cyclopolymers elucidated poly(1,7-octadiyne) 1,7-octadiyne-4,4-dicarboxylic esters containing enantiomerically menthyl ester groups. These investigations revealed formation highly tactic (>86%) at least predominantly trans-configured exocyclic double bonds.