Organocatalytic C-F Bond Activation with Alanes was written by Jaeger, Alma D.;Ehm, Christian;Lentz, Dieter. And the article was included in Chemistry – A European Journal in 2018.Name: 2,3,4,5,6-Perfluoropyridine The following contents are mentioned in the article:
Hydrodefluorination reactions (HDF) of per- and polyfluorinated olefins and arenes by cheap aluminum alkyl hydrides in non-coordinating solvents can be catalyzed by O and N donors. TONs with respect to the organocatalysts of up to 87 have been observed Depending on substrate and concentration, high selectivities can be achieved. For the prototypical hexafluoropropene, however, low selectivities are observed (E/Z≈2). DFT studies show that the preferred HDF mechanism for this substrate in the presence of donor solvents proceeds from the dimer Me4Al2(μ-H)2·THF by nucleophilic vinylic substitution (SNV)-like transition states with low selectivity and without formation of an intermediate, not via hydrometallation or σ-bond metathesis. In the absence of donor solvents, hydrometallation is preferred but this is associated with inaccessibly high activation barriers at low temperatures Donor solvents activate the aluminum hydride bond, lower the barrier for HDF significantly, and switch the product preference from Z to E. The exact nature of the donor has only a minimal influence on the selectivity at low concentrations, as the donor is located far away from the active center in the transition states. The mechanism changes at higher donor concentrations and proceeds from Me2AlH·THF via SNV and formation of a stable intermediate, from which elimination is unselective, which results in a loss of selectivity. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Name: 2,3,4,5,6-Perfluoropyridine).
2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Name: 2,3,4,5,6-Perfluoropyridine