Tetraphosphacubanes and isomeric cage compounds

CI3C-CCI3 CsHs, 25 °C - Cp2ZrCt2 -Cl2C=CClz 

As already mentioned, the modest yield of tetraphosphacubane from the reaction 59 c -+ 53 c is due to the formation of isomeric polycyclic compounds. 

As already mentioned (see Section 6.5.1.6), the phosphorus atoms in the tetrapbosphacubane system have lost basicity/nucleophilicity on account of the participation of the phosphorus lone electron pairs in the P-C o-bonds. Particularly strongly electrophilic reagents are thus 

---