Phosphine-catalyzed Highly Diastereoselective [3+2] Cyclization Of Isatin Derived Electron-deficient Alkenes With α-Allenic Esters

The first part of dissertation is carried out on the reactions of isatin derived electron-deficient alkenes with a-allenic esters catalyzed by two kinds of phophine. The second part of this dissertation focused on the route of 5'-(3-mercaptopropoxy)nucleotide.1 We designed new isatin derived electron-deficient alkenes reaction with a-allenic esters catalyzed by phosphine, it gave two highly diastereoselective products were formed after 8 hours at room temperature. When PBu3(20 mol%) was used as phosphine catalyst, the result was very different from P(4-FC6H4)3. In the face of this result, we assumed a plausible mechanism to explain it.2 Owing to the special structure of nucleotide deviant, we designed new route to synthesize 5'-(3-mercaptopropoxy)nucleotide. From the substrate and framed good route, we made many attempt to synthesize the four compounds. In despite of that we only synthesized one the them, it give a good reference to us.