N-Heterocyclic carbene phosphaketene adducts as precursors to carbene–phosphinidene adducts and a rearranged π-system

Abstract

The nucleophilic attack of NHCs on the electron deficient carbon of tetryl substituted phosphaketenes Ph3E-P[double bond, length as m-dash]C[double bond, length as m-dash]O (E = Sn-Si), leads quantitatively to the formation of NHC-phosphaketene adducts. With E = Sn or Ge, these zwitterionic adducts decompose upon thermolysis under the release of carbon monoxide to give zwitterionic NHC-phosphinidene adducts. With E = Si an OCP to CPO rearrangement occurs which leads to the formation of a linear π-conjugated molecule, NHC[double bond, length as m-dash]C[double bond, length as m-dash]P-O-SiPh3.