Single-Crystal to Single-Crystal Transformations: Stepwise CO Insertions into Bridging Hydrides of [(NHC)CuH] Complexes.

Mechanistic studies of substrate insertion into dimeric [(NHC)CuH] (NHC=N-heterocyclic carbene) complexes with two bridging hydrides have been shown to require dimer dissociation to generate transient, highly reactive (NHC)Cu-H monomers in solution. Using single-crystal to single-crystal (SC-SC) transformations, we discovered a new pathway of stepwise insertion of CO into [(NHC)CuH] without complete dissociation of the dimer. The first CO insertion into dimeric [(IPr*OMe)CuH] (IPr*OMe=N,N'-bis(2,6-bis(diphenylmethyl)-4-methoxy-phenyl)imidazole-2-ylidene) produced a dicopper formate hydride [(IPr*OMe)Cu] (μ-1,3-O CH)(μ-H).

A monoanionic pentadentate ligand platform for scandium-pnictogen multiple bonds.

A new monoanionic pentadentate ligand is designed to accommodate Sc = E bonds (E = N, P). The imido complex is stable enough to isolate and characterize, and reacts rapidly with CO. The phosphinidene, on the other hand, is highly reactive and induces C-C bond cleavage to yield a phosphido-pyridyl complex which also undergoes rapid reacton with CO.

Twenty-five years of bis-pentafluorophenyl borane: a versatile reagent for catalyst and materials synthesis.

In 1995, the synthesis, properties and remarkable hydroboration activity of bis-pentafluorophenyl borane was first reported. Its reactivity stems from the ready accessibility of the monomeric borane and its high Lewis acidity. In the intervening twenty five years, this reagent has been widely exploited as a means of incorporating Lewis acidic -B(C6F5)2 groups into complex structures for a range of applications.