Reactions of Li/Cl Phosphinidenoid Complexes with 1,3,4,5‐Tetramethylimidazol‐2‐ylidene: A New Route to N‐Heterocyclic Carbene Adducts of Terminal Phosphinidene Complexes and an Unprecedented Transformation of an Oxaphosphirane Complex

Abstract

Abstract The reaction of Li/Cl phosphinidenoid tungsten(0) complex 2 [R = CH(SiMe 3 ) 2 ] with 1,3,4,5‐tetramethylimidazol‐2‐ylidene ( 3 ) yielded the zwitterionic phosphaalkene complex 4 . A comparative study on chloro‐ ( 5 ) or dichloro(organo)phosphane complexes 1 [R = CH(SiMe 3 ) 2 ] and NHC 3 revealed the formation of 4 at ambient temperature. First evidence for the formation of phosphinidenoid complex 7 , having a C ‐Cl imidazolium cation, and its reaction with benzaldehyde to give oxaphosphirane complex 9 are presented. Furthermore, the first example of a formal exchange at the phosphorus center of an oxaphosphirane complex to give zwitterion 4 is demonstrated.