Gallium Hydrides and O/N-Donors as Tunable Systems in C-F Bond Activation.

The gallium hydrides (iBu) GaH (1 a), LiGaH (1 b) and Me N⋅GaH (1 c) hydrodefluorinate vinylic and aromatic C-F bonds when O and N donor molecules are present. 1 b exhibits the highest reactivity. Quantitative conversion to the hydrodefluorination (HDF) products could be observed for hexafluoropropene and 1,1,3,3,3-pentafluoropropene, 94 % conversion of pentafluoropyridine and 49 % of octafluorotoluene.

Organocatalytic C-F Bond Activation with Alanes.

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.