Preparation and Reactions of Cationic Zirconacycles

为了开发利用锆阳离子物种的新型反应，我们合成了新型的锆络合物，并将其用于该项目。用二丁基二茂锆盐处理C2位含氯的二烯类化合物时，它们会发生环化反应。在该反应中，二烯部分环化生成锆环戊烷作为环化产物。二烯的C2碳上的氯进入了锆环戊烷的β-位。然后，由于β-位上的氯，进一步的反应继续进行。氯化物被消除，该部分转化为碳-碳双键，被消除的氯化物被金属锆中心捕获。通过该反应得到了烷基二茂锆氯化物。当用MAO(甲基铝氧烷)和苯乙炔处理这些化合物时，观察到了一种新型的插入反应。

In order to develop novel type of reactions using zirconium cation species, we synthesized novel zirconium complexes which were used for the project as a target. Dienes which have a chloride at C2 carbon cyclized, when they were treated with dibutylzirconocene. In this reaction, the diene moiety cyclized to form a zirconacyclopentane as the cyclized product. The chloride at C2 carbon of dienes came to β-position of zirconacyclopentanes. And then further reaction proceeded because of the chloride at β-position. Elimination of the chloride occurred and this moiety was converted into a carbon-carbon double bond and the eliminated chloride was trapped by zirconium metal center. By this reaction alkylzirconocene chlorides were obtained. When the compounds were treated with MAO (methylalumoxane) and the phenylacetylene, novel type of insertion reaction was observed.