Metallapolycycles from the Coupling of Two Re–C Bonds

The metal center can form multiple σ-bonds with a polydentate ligand. In this work, novel rhenapolycycles with up to six σ-bonds (four Re–C and two Re–N σ-bonds) are obtained from the reaction of ReCl3(PPh3)2(NCCH3) or ReOCl2(OEt)(PPh3)2 with 2-ethynylaniline. The key step is proposed to be the coupling of two Re–C bonds in Re(V)bisvinyl or bis(alkenyl ylide) structures.