1423-10-5Relevant articles and documents
Facile H/D exchange at (hetero)aromatic hydrocarbons catalyzed by a stable trans-dihydride n-heterocyclic carbene (NHC) iron complex
De Ruiter, Graham,Garhwal, Subhash,Kaushansky, Alexander,Fridman, Natalia,Shimon, Linda J.W.
supporting information, p. 17131 - 17139 (2020/11/09)
Earth-abundant metal pincer complexes have played an important role in homogeneous catalysis during the last ten years. Yet, despite intense research efforts, the synthesis of iron PCcarbeneP pincer complexes has so far remained elusive. Here we report the synthesis of the first PCNHCP functionalized iron complex [(PCNHCP)FeCl2] (1) and the reactivity of the corresponding trans-dihydride iron(II) dinitrogen complex [(PCNHCP)- Fe(H)2N2)] (2). Complex 2 is stable under an atmosphere of N2 and is highly active for hydrogen isotope exchange at (hetero)aromatic hydrocarbons under mild conditions (50 °C, N2). With benzene-d6 as the deuterium source, easily reducible functional groups such as esters and amides are well tolerated, contributing to the overall wide substrate scope (e.g., halides, ethers, and amines). DFT studies suggest a complex assisted σ-bond metathesis pathway for C(sp2)-H bond activation, which is further discussed in this study.
The thermal conversions of 6,6-difluorobicyclo[3.1.0]hex-2-enes to fluorobenzenes. An interesting dichotomy of mechanisms
Dolbier Jr.,Keaffaber,Burkholder,Koroniak,Pradhan
, p. 9649 - 9660 (2007/10/02)
A kinetic study of the thermal, dehydrofluorinative aromatization reactions of two ostensibly-similar 6,6-difluorobicyclo[3.1.0]hex-2-ene systems led to the conclusion that drastically different mechanisms operate for the two reactions. Activation parameters, solvent effects, kinetic isotope effects, isotope labelling experiments and observation of reactive intermediates all contributed to the conclusion that the reaction of 6,6-difluorobicyclo[3.1.0]hex-2-ene, 1, proceeds via a homolytic hydrogen-shift rearrangement, while the reaction of 2,3-benzo-6,6-difluorobicyclo[3.1.0]hex-2-ene, 6, proceeds via a solvolytic mechanism involving rate-determining carbocation formation.