Norbomene derivatives 7-11 were prepared from norbornadiene and the corresponding diynes by Ru-catalyzed [(2+2)+2] cycloaddition and subsequent transfer hydrogenation. The structure and stereochemistry of the cycloadducts were confirmed by X-ray crystal analysis. This procedure provides high diastereoselectivity to generate norbornenes 7-11 in up to 82 % yield. The scope and limitations of this reaction were investigated. Compounds that contained the skeleton of 1,7diaryl-1,6-heptadiynes were suitable starting materials. Additionly, 9h was empolyed in the synthesis of polynorbomene 31 by ring-opening metathesis polymerization (ROMP). The number-average molecular weight (M n) and polymer-distribution index (PDI) of this new polymer were determined to be 28.6 kDa and 1.35, respectively.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry