and facile method to synthesize zwitterionic nido-carborane-fused five-membered P-heterocycles was developed. Intermolecular cyclization between carboranylphosphines and electron-deficient alkynes occurred at 50 °C in THF, affording the products with up to 82% yield. For unsymmetrical alkynes, the more electrical-deficient site is selectively connected to phosphorus in the products. Structures of three
开发了一种高效、简便的方法来合成两性离子nido-碳
硼烷稠合的五元 P-杂环。碳
硼基膦和缺电子
炔烃在 50°C 下在 THF 中发生分子间环化,产物产率高达 82%。对于不对称
炔烃,更缺电的位点选择性地与产物中的
磷相连。三种产物的结构已通过单晶的 X 射线衍射分析得到证实。该反应的关键步骤被认为是碳
硼烷的酸性 C-H 被碳
硼烷膦与
炔烃加成得到的烯基阴离子去质子化。