Addition of a phosphinidene complex to C=N bonds: P-ylides, azaphosphiridines, and 1,3-dipolar cycloadditions.
Addition of a phosphinidene complex to C=N bonds: P-ylides, azaphosphiridines, and 1,3-dipolar cycloadditions.
复制标题
膦亚基配合物与 C=N 键的加成：P-叶立德、氮杂磷啶和 1,3-偶极环加成。
作者：
M. Vlaar;P. Valkier;F. de Kanter;M. Schakel;A. Ehlers;A. Spek;M. Lutz;K. Lammertsma
末端的磷膦配合物PhPW(CO)5与PhHC=N-Ph的亚胺键结合，得到3元环氮杂膦，再与另一个亚胺进行扩环，得到4个异构体五元环氮杂膦。用二亚胺PhHC=N-(CH2) N- N=CHPh （N= 2,3,4）处理，在所有三种情况下，只得到（CH2） N桥接重氮磷烷的单一异构体。当n=2或3时，该动物基团容易水解生成新的6元和7元环杂环。在与二亚胺的加成反应中没有观察到中间氮杂吡啶络合物。B3LYP/6-31G*对未取代、未络合体系的计算表明，H2C=N-(CH)2-N=CH2二亚胺的初始形成的P，N-酰化物在动力学和热力学上都倾向于分子内的1,3偶极环加成，而不是亚胺插入到中间氮磷啶的CPN环上。给出了（CH2）2桥联氮磷烷配合物和七元水解产物的HCl加合物的单晶x射线结构。
The terminal phosphinidene complex PhPW(CO)5 adds to the imine bond of PhHC=N-Ph to give 3-membered ring azaphosphiridines, which undergo ring-expansion with an additional imine to yield a set of four isomeric five-membered ring diazaphospholanes. Treatment with the diimines PhHC=N-(CH2)n-N=CHPh (n=2,3,4) results instead-in all three cases-in only a single isomer of the (CH2)n bridged diazaphospholane. For n=2 or 3, this aminal group is easily hydrolyzed to afford new 6- and 7-membered ring heterocycles. No intermediate azaphosphiridine complex is observed during the addition reaction to the diimines. B3LYP/6-31G* calculations on an unsubstituted, uncomplexed system suggest that the initially formed P,N-ylide of the H2C=N-(CH)2-N=CH2 diimine both kinetically and thermodynamically favors an intramolecular 1,3-dipolar cycloaddition over an imine insertion into the CPN ring of an intermediate azaphosphiridine. Single-crystal X-ray structures for the (CH2)2-bridged azaphospholane complex and the HCl adduct of the 7-membered hydrolysis product are presented.