Isolation and characterization of a monomeric metallapyridine complex: Models for pyridine hydrodenitrogenation intermediates

Article abstract of DOI:10.1016/S0022-328X(96)06612-0

We report the preparation of a stable metallapyridine complex of tantalum prepared in the course of model studies of hydrodenitrogenation reactions. Monomeric Ta(=NC^tBu=CHC^tBu=CH)(OAr)₂(THF)(5 · THF) is isolated upon thermolyzing the η²(N,C)-pyridine complex [η²(N.C)-2,4,6-NC^t₅Bu₃H₂]Ta(OAr)₂Me (2) in THF, while the metallapyridine dimer [Ta( μ - NC^tBu=CH - -C^tBu=CH)(OAr)₂]₂ (6) is isolated when this reaction is carried out in benzene. Complete NMR characterization of 5 · THF is described, along with its conversion into 6.