Extending the Scope of the B(C6 F5 )3 -Catalyzed C=N Bond Reduction: Hydrogenation of Oxime Ethers and Hydrazones.
The B(C6 F5 )3 -catalyzed hydrogenation is applied to aldoxime triisopropylsilyl ethers and hydrazones bearing an easily removable phthaloyl protective group. The CN reduction of aldehyde-derived substrates (oxime ethers and hydrazones) is enabled by using 1,4-dioxane as the solvent known to participate as the Lewis-basic component in FLP-type heterolytic dihydrogen splitting. More basic ketone-derived hydrazones act as Lewis bases themselves in the FLP-type dihydrogen activation and are therefore successfully hydrogenated in nondonating toluene. The difference in reactivity between aldehyde- and ketone-derived substrates is also reflected in the required catalyst loading and dihydrogen pressure.
Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, 10623 Berlin (Germany) http://www.organometallics.tu-berlin.de.
Jens
J
Mohr
Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, 10623 Berlin (Germany) http://www.organometallics.tu-berlin.de.
Digvijay
D
Porwal
Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, 10623 Berlin (Germany) http://www.organometallics.tu-berlin.de.
Indranil
I
Chatterjee
Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, 10623 Berlin (Germany) http://www.organometallics.tu-berlin.de. martin.oestreich@tu-berlin.de.
Martin
M
Oestreich
Lewis acids; boron; homogeneous catalysis; hydrogenation; reduction