Simple, convenient methods for the preparation of alkyne-Co2(CO)6 complexes from CoBr2 for application in Pauson-Khand cyclopentenone synthesis
作者:Mariappan Periasamy、Malladi Rama Reddy、Arokiasamy Devasagayaraj
DOI:10.1016/s0040-4020(01)81348-x
日期:1994.1
Alkyne-dicobalthexacarbonyl complexes are readily prepared by the reduction of cobalt bromide by Zn in the presence of alkynes in THF while bubbling carbon monoxide under ambient conditions. The complexes prepared in this way react with olefins to give the corresponding Pauson-Khand cyclopentenones in moderate to good yields. The alkyne-dicobalthexacarbonyl complexes can be also prepared in situ by
炔烃-二钴六羰基配合物可通过在炔烃存在下于THF中同时在环境条件下鼓泡一氧化碳的情况下,通过Zn还原溴化钴而制得。以这种方式制备的配合物与烯烃反应,以中等至良好的产率得到相应的Pauson-Khand环戊烯酮。炔-二钴六羰基配合物还可以通过在CO气氛下用萘钠还原溴化钴,然后在炔烃的存在下进行CuBr处理来原位制备。用这种方法制得的配合物在与降冰片烯加热下也能得到环戊烯,但前一种利用锌的方法能得到更好的结果。