Oligomerization and Hydroamination of Terminal Alkynes Promoted by the Cationic Organoactinide Compound [(Et2N)3U][BPh4]
作者:Jiaxi Wang、Aswini Kumar Dash、Moshe Kapon、Jean-Claude Berthet、Michel Ephritikhine、Moris S. Eisen
DOI:10.1002/1521-3765(20021202)8:23<5384::aid-chem5384>3.0.co;2-x
日期:2002.12.2
hydroamination imine as the major product. However, when other bulkier amines were used (iPrNH2 or tBuNH2) both hydroamination isomeric imines Z and E were obtained. During the catalytic reaction, the E (kinetic) isomer is transformed into the most stable Z (thermodynamic) isomer. The unique reactivity of the alkyne (TMS) C identical to CH with the secondary amine Et2NH is remarkable because it afforded
阳离子络合物[(Et2N)3U] [BPh4]中的三个辅助酰胺基部分具有很高的反应性,当用伯胺处理该络合物时,很容易被取代。[(Et2N)3U] [BPh4]与过量的tBuNH2的反应可以形成阳离子络合物[(tBuNH2)3(tBuNH)3U] [BPh4]。对络合物的X射线衍射研究表明,三个酰胺和三个胺配体以略微扭曲的八面体mer几何形状排列在阳离子金属中心周围。阳离子络合物在外部伯胺存在下与伯炔反应,主要提供意外的顺式二聚体,在某些情况下,同时获得加氢胺化产物。顺式二聚体的形成是通过金属-环丙基阳离子络合物的包膜异构化的结果。如氘标记实验所证实,在各种伯胺的存在下,与CH相同的大体积炔烃tBuC与阳离子铀络合物的反应中,区域选择性地获得了顺二聚体,一个三聚体和一个四聚体。三聚体和四聚体对应于炔烃分子连续插入到乙烯基CH键中,该乙烯基CH键反过来是庞大的叔丁基。在EtNH2存在下,(TM